// SPDX-License-Identifier: GPL-2.0+ /* * Freescale lpuart serial port driver * * Copyright 2012-2014 Freescale Semiconductor, Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* All registers are 8-bit width */ #define UARTBDH 0x00 #define UARTBDL 0x01 #define UARTCR1 0x02 #define UARTCR2 0x03 #define UARTSR1 0x04 #define UARTCR3 0x06 #define UARTDR 0x07 #define UARTCR4 0x0a #define UARTCR5 0x0b #define UARTMODEM 0x0d #define UARTPFIFO 0x10 #define UARTCFIFO 0x11 #define UARTSFIFO 0x12 #define UARTTWFIFO 0x13 #define UARTTCFIFO 0x14 #define UARTRWFIFO 0x15 #define UARTBDH_LBKDIE 0x80 #define UARTBDH_RXEDGIE 0x40 #define UARTBDH_SBR_MASK 0x1f #define UARTCR1_LOOPS 0x80 #define UARTCR1_RSRC 0x20 #define UARTCR1_M 0x10 #define UARTCR1_WAKE 0x08 #define UARTCR1_ILT 0x04 #define UARTCR1_PE 0x02 #define UARTCR1_PT 0x01 #define UARTCR2_TIE 0x80 #define UARTCR2_TCIE 0x40 #define UARTCR2_RIE 0x20 #define UARTCR2_ILIE 0x10 #define UARTCR2_TE 0x08 #define UARTCR2_RE 0x04 #define UARTCR2_RWU 0x02 #define UARTCR2_SBK 0x01 #define UARTSR1_TDRE 0x80 #define UARTSR1_TC 0x40 #define UARTSR1_RDRF 0x20 #define UARTSR1_IDLE 0x10 #define UARTSR1_OR 0x08 #define UARTSR1_NF 0x04 #define UARTSR1_FE 0x02 #define UARTSR1_PE 0x01 #define UARTCR3_R8 0x80 #define UARTCR3_T8 0x40 #define UARTCR3_TXDIR 0x20 #define UARTCR3_TXINV 0x10 #define UARTCR3_ORIE 0x08 #define UARTCR3_NEIE 0x04 #define UARTCR3_FEIE 0x02 #define UARTCR3_PEIE 0x01 #define UARTCR4_MAEN1 0x80 #define UARTCR4_MAEN2 0x40 #define UARTCR4_M10 0x20 #define UARTCR4_BRFA_MASK 0x1f #define UARTCR4_BRFA_OFF 0 #define UARTCR5_TDMAS 0x80 #define UARTCR5_RDMAS 0x20 #define UARTMODEM_RXRTSE 0x08 #define UARTMODEM_TXRTSPOL 0x04 #define UARTMODEM_TXRTSE 0x02 #define UARTMODEM_TXCTSE 0x01 #define UARTPFIFO_TXFE 0x80 #define UARTPFIFO_FIFOSIZE_MASK 0x7 #define UARTPFIFO_TXSIZE_OFF 4 #define UARTPFIFO_RXFE 0x08 #define UARTPFIFO_RXSIZE_OFF 0 #define UARTCFIFO_TXFLUSH 0x80 #define UARTCFIFO_RXFLUSH 0x40 #define UARTCFIFO_RXOFE 0x04 #define UARTCFIFO_TXOFE 0x02 #define UARTCFIFO_RXUFE 0x01 #define UARTSFIFO_TXEMPT 0x80 #define UARTSFIFO_RXEMPT 0x40 #define UARTSFIFO_RXOF 0x04 #define UARTSFIFO_TXOF 0x02 #define UARTSFIFO_RXUF 0x01 /* 32-bit register definition */ #define UARTBAUD 0x00 #define UARTSTAT 0x04 #define UARTCTRL 0x08 #define UARTDATA 0x0C #define UARTMATCH 0x10 #define UARTMODIR 0x14 #define UARTFIFO 0x18 #define UARTWATER 0x1c #define UARTBAUD_MAEN1 0x80000000 #define UARTBAUD_MAEN2 0x40000000 #define UARTBAUD_M10 0x20000000 #define UARTBAUD_TDMAE 0x00800000 #define UARTBAUD_RDMAE 0x00200000 #define UARTBAUD_MATCFG 0x00400000 #define UARTBAUD_BOTHEDGE 0x00020000 #define UARTBAUD_RESYNCDIS 0x00010000 #define UARTBAUD_LBKDIE 0x00008000 #define UARTBAUD_RXEDGIE 0x00004000 #define UARTBAUD_SBNS 0x00002000 #define UARTBAUD_SBR 0x00000000 #define UARTBAUD_SBR_MASK 0x1fff #define UARTBAUD_OSR_MASK 0x1f #define UARTBAUD_OSR_SHIFT 24 #define UARTSTAT_LBKDIF 0x80000000 #define UARTSTAT_RXEDGIF 0x40000000 #define UARTSTAT_MSBF 0x20000000 #define UARTSTAT_RXINV 0x10000000 #define UARTSTAT_RWUID 0x08000000 #define UARTSTAT_BRK13 0x04000000 #define UARTSTAT_LBKDE 0x02000000 #define UARTSTAT_RAF 0x01000000 #define UARTSTAT_TDRE 0x00800000 #define UARTSTAT_TC 0x00400000 #define UARTSTAT_RDRF 0x00200000 #define UARTSTAT_IDLE 0x00100000 #define UARTSTAT_OR 0x00080000 #define UARTSTAT_NF 0x00040000 #define UARTSTAT_FE 0x00020000 #define UARTSTAT_PE 0x00010000 #define UARTSTAT_MA1F 0x00008000 #define UARTSTAT_M21F 0x00004000 #define UARTCTRL_R8T9 0x80000000 #define UARTCTRL_R9T8 0x40000000 #define UARTCTRL_TXDIR 0x20000000 #define UARTCTRL_TXINV 0x10000000 #define UARTCTRL_ORIE 0x08000000 #define UARTCTRL_NEIE 0x04000000 #define UARTCTRL_FEIE 0x02000000 #define UARTCTRL_PEIE 0x01000000 #define UARTCTRL_TIE 0x00800000 #define UARTCTRL_TCIE 0x00400000 #define UARTCTRL_RIE 0x00200000 #define UARTCTRL_ILIE 0x00100000 #define UARTCTRL_TE 0x00080000 #define UARTCTRL_RE 0x00040000 #define UARTCTRL_RWU 0x00020000 #define UARTCTRL_SBK 0x00010000 #define UARTCTRL_MA1IE 0x00008000 #define UARTCTRL_MA2IE 0x00004000 #define UARTCTRL_IDLECFG 0x00000100 #define UARTCTRL_LOOPS 0x00000080 #define UARTCTRL_DOZEEN 0x00000040 #define UARTCTRL_RSRC 0x00000020 #define UARTCTRL_M 0x00000010 #define UARTCTRL_WAKE 0x00000008 #define UARTCTRL_ILT 0x00000004 #define UARTCTRL_PE 0x00000002 #define UARTCTRL_PT 0x00000001 #define UARTDATA_NOISY 0x00008000 #define UARTDATA_PARITYE 0x00004000 #define UARTDATA_FRETSC 0x00002000 #define UARTDATA_RXEMPT 0x00001000 #define UARTDATA_IDLINE 0x00000800 #define UARTDATA_MASK 0x3ff #define UARTMODIR_IREN 0x00020000 #define UARTMODIR_TXCTSSRC 0x00000020 #define UARTMODIR_TXCTSC 0x00000010 #define UARTMODIR_RXRTSE 0x00000008 #define UARTMODIR_TXRTSPOL 0x00000004 #define UARTMODIR_TXRTSE 0x00000002 #define UARTMODIR_TXCTSE 0x00000001 #define UARTFIFO_TXEMPT 0x00800000 #define UARTFIFO_RXEMPT 0x00400000 #define UARTFIFO_TXOF 0x00020000 #define UARTFIFO_RXUF 0x00010000 #define UARTFIFO_TXFLUSH 0x00008000 #define UARTFIFO_RXFLUSH 0x00004000 #define UARTFIFO_TXOFE 0x00000200 #define UARTFIFO_RXUFE 0x00000100 #define UARTFIFO_TXFE 0x00000080 #define UARTFIFO_FIFOSIZE_MASK 0x7 #define UARTFIFO_TXSIZE_OFF 4 #define UARTFIFO_RXFE 0x00000008 #define UARTFIFO_RXSIZE_OFF 0 #define UARTFIFO_DEPTH(x) (0x1 << ((x) ? ((x) + 1) : 0)) #define UARTWATER_COUNT_MASK 0xff #define UARTWATER_TXCNT_OFF 8 #define UARTWATER_RXCNT_OFF 24 #define UARTWATER_WATER_MASK 0xff #define UARTWATER_TXWATER_OFF 0 #define UARTWATER_RXWATER_OFF 16 /* Rx DMA timeout in ms, which is used to calculate Rx ring buffer size */ #define DMA_RX_TIMEOUT (10) #define DRIVER_NAME "fsl-lpuart" #define DEV_NAME "ttyLP" #define UART_NR 6 /* IMX lpuart has four extra unused regs located at the beginning */ #define IMX_REG_OFF 0x10 enum lpuart_type { VF610_LPUART, LS1021A_LPUART, LS1028A_LPUART, IMX7ULP_LPUART, IMX8QXP_LPUART, }; struct lpuart_port { struct uart_port port; enum lpuart_type devtype; struct clk *ipg_clk; struct clk *baud_clk; unsigned int txfifo_size; unsigned int rxfifo_size; bool lpuart_dma_tx_use; bool lpuart_dma_rx_use; struct dma_chan *dma_tx_chan; struct dma_chan *dma_rx_chan; struct dma_async_tx_descriptor *dma_tx_desc; struct dma_async_tx_descriptor *dma_rx_desc; dma_cookie_t dma_tx_cookie; dma_cookie_t dma_rx_cookie; unsigned int dma_tx_bytes; unsigned int dma_rx_bytes; bool dma_tx_in_progress; unsigned int dma_rx_timeout; struct timer_list lpuart_timer; struct scatterlist rx_sgl, tx_sgl[2]; struct circ_buf rx_ring; int rx_dma_rng_buf_len; unsigned int dma_tx_nents; wait_queue_head_t dma_wait; }; struct lpuart_soc_data { enum lpuart_type devtype; char iotype; u8 reg_off; }; static const struct lpuart_soc_data vf_data = { .devtype = VF610_LPUART, .iotype = UPIO_MEM, }; static const struct lpuart_soc_data ls1021a_data = { .devtype = LS1021A_LPUART, .iotype = UPIO_MEM32BE, }; static const struct lpuart_soc_data ls1028a_data = { .devtype = LS1028A_LPUART, .iotype = UPIO_MEM32, }; static struct lpuart_soc_data imx7ulp_data = { .devtype = IMX7ULP_LPUART, .iotype = UPIO_MEM32, .reg_off = IMX_REG_OFF, }; static struct lpuart_soc_data imx8qxp_data = { .devtype = IMX8QXP_LPUART, .iotype = UPIO_MEM32, .reg_off = IMX_REG_OFF, }; static const struct of_device_id lpuart_dt_ids[] = { { .compatible = "fsl,vf610-lpuart", .data = &vf_data, }, { .compatible = "fsl,ls1021a-lpuart", .data = &ls1021a_data, }, { .compatible = "fsl,ls1028a-lpuart", .data = &ls1028a_data, }, { .compatible = "fsl,imx7ulp-lpuart", .data = &imx7ulp_data, }, { .compatible = "fsl,imx8qxp-lpuart", .data = &imx8qxp_data, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, lpuart_dt_ids); /* Forward declare this for the dma callbacks*/ static void lpuart_dma_tx_complete(void *arg); static inline bool is_layerscape_lpuart(struct lpuart_port *sport) { return (sport->devtype == LS1021A_LPUART || sport->devtype == LS1028A_LPUART); } static inline bool is_imx8qxp_lpuart(struct lpuart_port *sport) { return sport->devtype == IMX8QXP_LPUART; } static inline u32 lpuart32_read(struct uart_port *port, u32 off) { switch (port->iotype) { case UPIO_MEM32: return readl(port->membase + off); case UPIO_MEM32BE: return ioread32be(port->membase + off); default: return 0; } } static inline void lpuart32_write(struct uart_port *port, u32 val, u32 off) { switch (port->iotype) { case UPIO_MEM32: writel(val, port->membase + off); break; case UPIO_MEM32BE: iowrite32be(val, port->membase + off); break; } } static int __lpuart_enable_clks(struct lpuart_port *sport, bool is_en) { int ret = 0; if (is_en) { ret = clk_prepare_enable(sport->ipg_clk); if (ret) return ret; ret = clk_prepare_enable(sport->baud_clk); if (ret) { clk_disable_unprepare(sport->ipg_clk); return ret; } } else { clk_disable_unprepare(sport->baud_clk); clk_disable_unprepare(sport->ipg_clk); } return 0; } static unsigned int lpuart_get_baud_clk_rate(struct lpuart_port *sport) { if (is_imx8qxp_lpuart(sport)) return clk_get_rate(sport->baud_clk); return clk_get_rate(sport->ipg_clk); } #define lpuart_enable_clks(x) __lpuart_enable_clks(x, true) #define lpuart_disable_clks(x) __lpuart_enable_clks(x, false) static void lpuart_stop_tx(struct uart_port *port) { unsigned char temp; temp = readb(port->membase + UARTCR2); temp &= ~(UARTCR2_TIE | UARTCR2_TCIE); writeb(temp, port->membase + UARTCR2); } static void lpuart32_stop_tx(struct uart_port *port) { unsigned long temp; temp = lpuart32_read(port, UARTCTRL); temp &= ~(UARTCTRL_TIE | UARTCTRL_TCIE); lpuart32_write(port, temp, UARTCTRL); } static void lpuart_stop_rx(struct uart_port *port) { unsigned char temp; temp = readb(port->membase + UARTCR2); writeb(temp & ~UARTCR2_RE, port->membase + UARTCR2); } static void lpuart32_stop_rx(struct uart_port *port) { unsigned long temp; temp = lpuart32_read(port, UARTCTRL); lpuart32_write(port, temp & ~UARTCTRL_RE, UARTCTRL); } static void lpuart_dma_tx(struct lpuart_port *sport) { struct circ_buf *xmit = &sport->port.state->xmit; struct scatterlist *sgl = sport->tx_sgl; struct device *dev = sport->port.dev; struct dma_chan *chan = sport->dma_tx_chan; int ret; if (sport->dma_tx_in_progress) return; sport->dma_tx_bytes = uart_circ_chars_pending(xmit); if (xmit->tail < xmit->head || xmit->head == 0) { sport->dma_tx_nents = 1; sg_init_one(sgl, xmit->buf + xmit->tail, sport->dma_tx_bytes); } else { sport->dma_tx_nents = 2; sg_init_table(sgl, 2); sg_set_buf(sgl, xmit->buf + xmit->tail, UART_XMIT_SIZE - xmit->tail); sg_set_buf(sgl + 1, xmit->buf, xmit->head); } ret = dma_map_sg(chan->device->dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); if (!ret) { dev_err(dev, "DMA mapping error for TX.\n"); return; } sport->dma_tx_desc = dmaengine_prep_slave_sg(chan, sgl, ret, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT); if (!sport->dma_tx_desc) { dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); dev_err(dev, "Cannot prepare TX slave DMA!\n"); return; } sport->dma_tx_desc->callback = lpuart_dma_tx_complete; sport->dma_tx_desc->callback_param = sport; sport->dma_tx_in_progress = true; sport->dma_tx_cookie = dmaengine_submit(sport->dma_tx_desc); dma_async_issue_pending(chan); } static bool lpuart_stopped_or_empty(struct uart_port *port) { return uart_circ_empty(&port->state->xmit) || uart_tx_stopped(port); } static void lpuart_dma_tx_complete(void *arg) { struct lpuart_port *sport = arg; struct scatterlist *sgl = &sport->tx_sgl[0]; struct circ_buf *xmit = &sport->port.state->xmit; struct dma_chan *chan = sport->dma_tx_chan; unsigned long flags; spin_lock_irqsave(&sport->port.lock, flags); dma_unmap_sg(chan->device->dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); xmit->tail = (xmit->tail + sport->dma_tx_bytes) & (UART_XMIT_SIZE - 1); sport->port.icount.tx += sport->dma_tx_bytes; sport->dma_tx_in_progress = false; spin_unlock_irqrestore(&sport->port.lock, flags); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&sport->port); if (waitqueue_active(&sport->dma_wait)) { wake_up(&sport->dma_wait); return; } spin_lock_irqsave(&sport->port.lock, flags); if (!lpuart_stopped_or_empty(&sport->port)) lpuart_dma_tx(sport); spin_unlock_irqrestore(&sport->port.lock, flags); } static dma_addr_t lpuart_dma_datareg_addr(struct lpuart_port *sport) { switch (sport->port.iotype) { case UPIO_MEM32: return sport->port.mapbase + UARTDATA; case UPIO_MEM32BE: return sport->port.mapbase + UARTDATA + sizeof(u32) - 1; } return sport->port.mapbase + UARTDR; } static int lpuart_dma_tx_request(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); struct dma_slave_config dma_tx_sconfig = {}; int ret; dma_tx_sconfig.dst_addr = lpuart_dma_datareg_addr(sport); dma_tx_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; dma_tx_sconfig.dst_maxburst = 1; dma_tx_sconfig.direction = DMA_MEM_TO_DEV; ret = dmaengine_slave_config(sport->dma_tx_chan, &dma_tx_sconfig); if (ret) { dev_err(sport->port.dev, "DMA slave config failed, err = %d\n", ret); return ret; } return 0; } static bool lpuart_is_32(struct lpuart_port *sport) { return sport->port.iotype == UPIO_MEM32 || sport->port.iotype == UPIO_MEM32BE; } static void lpuart_flush_buffer(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); struct dma_chan *chan = sport->dma_tx_chan; u32 val; if (sport->lpuart_dma_tx_use) { if (sport->dma_tx_in_progress) { dma_unmap_sg(chan->device->dev, &sport->tx_sgl[0], sport->dma_tx_nents, DMA_TO_DEVICE); sport->dma_tx_in_progress = false; } dmaengine_terminate_all(chan); } if (lpuart_is_32(sport)) { val = lpuart32_read(&sport->port, UARTFIFO); val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH; lpuart32_write(&sport->port, val, UARTFIFO); } else { val = readb(sport->port.membase + UARTCFIFO); val |= UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH; writeb(val, sport->port.membase + UARTCFIFO); } } static void lpuart_wait_bit_set(struct uart_port *port, unsigned int offset, u8 bit) { while (!(readb(port->membase + offset) & bit)) cpu_relax(); } static void lpuart32_wait_bit_set(struct uart_port *port, unsigned int offset, u32 bit) { while (!(lpuart32_read(port, offset) & bit)) cpu_relax(); } #if defined(CONFIG_CONSOLE_POLL) static int lpuart_poll_init(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long flags; unsigned char temp; sport->port.fifosize = 0; spin_lock_irqsave(&sport->port.lock, flags); /* Disable Rx & Tx */ writeb(0, sport->port.membase + UARTCR2); temp = readb(sport->port.membase + UARTPFIFO); /* Enable Rx and Tx FIFO */ writeb(temp | UARTPFIFO_RXFE | UARTPFIFO_TXFE, sport->port.membase + UARTPFIFO); /* flush Tx and Rx FIFO */ writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); /* explicitly clear RDRF */ if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) { readb(sport->port.membase + UARTDR); writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO); } writeb(0, sport->port.membase + UARTTWFIFO); writeb(1, sport->port.membase + UARTRWFIFO); /* Enable Rx and Tx */ writeb(UARTCR2_RE | UARTCR2_TE, sport->port.membase + UARTCR2); spin_unlock_irqrestore(&sport->port.lock, flags); return 0; } static void lpuart_poll_put_char(struct uart_port *port, unsigned char c) { /* drain */ lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE); writeb(c, port->membase + UARTDR); } static int lpuart_poll_get_char(struct uart_port *port) { if (!(readb(port->membase + UARTSR1) & UARTSR1_RDRF)) return NO_POLL_CHAR; return readb(port->membase + UARTDR); } static int lpuart32_poll_init(struct uart_port *port) { unsigned long flags; struct lpuart_port *sport = container_of(port, struct lpuart_port, port); u32 temp; sport->port.fifosize = 0; spin_lock_irqsave(&sport->port.lock, flags); /* Disable Rx & Tx */ lpuart32_write(&sport->port, 0, UARTCTRL); temp = lpuart32_read(&sport->port, UARTFIFO); /* Enable Rx and Tx FIFO */ lpuart32_write(&sport->port, temp | UARTFIFO_RXFE | UARTFIFO_TXFE, UARTFIFO); /* flush Tx and Rx FIFO */ lpuart32_write(&sport->port, UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH, UARTFIFO); /* explicitly clear RDRF */ if (lpuart32_read(&sport->port, UARTSTAT) & UARTSTAT_RDRF) { lpuart32_read(&sport->port, UARTDATA); lpuart32_write(&sport->port, UARTFIFO_RXUF, UARTFIFO); } /* Enable Rx and Tx */ lpuart32_write(&sport->port, UARTCTRL_RE | UARTCTRL_TE, UARTCTRL); spin_unlock_irqrestore(&sport->port.lock, flags); return 0; } static void lpuart32_poll_put_char(struct uart_port *port, unsigned char c) { lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE); lpuart32_write(port, c, UARTDATA); } static int lpuart32_poll_get_char(struct uart_port *port) { if (!(lpuart32_read(port, UARTWATER) >> UARTWATER_RXCNT_OFF)) return NO_POLL_CHAR; return lpuart32_read(port, UARTDATA); } #endif static inline void lpuart_transmit_buffer(struct lpuart_port *sport) { struct circ_buf *xmit = &sport->port.state->xmit; if (sport->port.x_char) { writeb(sport->port.x_char, sport->port.membase + UARTDR); sport->port.icount.tx++; sport->port.x_char = 0; return; } if (lpuart_stopped_or_empty(&sport->port)) { lpuart_stop_tx(&sport->port); return; } while (!uart_circ_empty(xmit) && (readb(sport->port.membase + UARTTCFIFO) < sport->txfifo_size)) { writeb(xmit->buf[xmit->tail], sport->port.membase + UARTDR); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); sport->port.icount.tx++; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&sport->port); if (uart_circ_empty(xmit)) lpuart_stop_tx(&sport->port); } static inline void lpuart32_transmit_buffer(struct lpuart_port *sport) { struct circ_buf *xmit = &sport->port.state->xmit; unsigned long txcnt; if (sport->port.x_char) { lpuart32_write(&sport->port, sport->port.x_char, UARTDATA); sport->port.icount.tx++; sport->port.x_char = 0; return; } if (lpuart_stopped_or_empty(&sport->port)) { lpuart32_stop_tx(&sport->port); return; } txcnt = lpuart32_read(&sport->port, UARTWATER); txcnt = txcnt >> UARTWATER_TXCNT_OFF; txcnt &= UARTWATER_COUNT_MASK; while (!uart_circ_empty(xmit) && (txcnt < sport->txfifo_size)) { lpuart32_write(&sport->port, xmit->buf[xmit->tail], UARTDATA); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); sport->port.icount.tx++; txcnt = lpuart32_read(&sport->port, UARTWATER); txcnt = txcnt >> UARTWATER_TXCNT_OFF; txcnt &= UARTWATER_COUNT_MASK; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&sport->port); if (uart_circ_empty(xmit)) lpuart32_stop_tx(&sport->port); } static void lpuart_start_tx(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned char temp; temp = readb(port->membase + UARTCR2); writeb(temp | UARTCR2_TIE, port->membase + UARTCR2); if (sport->lpuart_dma_tx_use) { if (!lpuart_stopped_or_empty(port)) lpuart_dma_tx(sport); } else { if (readb(port->membase + UARTSR1) & UARTSR1_TDRE) lpuart_transmit_buffer(sport); } } static void lpuart32_start_tx(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long temp; if (sport->lpuart_dma_tx_use) { if (!lpuart_stopped_or_empty(port)) lpuart_dma_tx(sport); } else { temp = lpuart32_read(port, UARTCTRL); lpuart32_write(port, temp | UARTCTRL_TIE, UARTCTRL); if (lpuart32_read(port, UARTSTAT) & UARTSTAT_TDRE) lpuart32_transmit_buffer(sport); } } /* return TIOCSER_TEMT when transmitter is not busy */ static unsigned int lpuart_tx_empty(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned char sr1 = readb(port->membase + UARTSR1); unsigned char sfifo = readb(port->membase + UARTSFIFO); if (sport->dma_tx_in_progress) return 0; if (sr1 & UARTSR1_TC && sfifo & UARTSFIFO_TXEMPT) return TIOCSER_TEMT; return 0; } static unsigned int lpuart32_tx_empty(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long stat = lpuart32_read(port, UARTSTAT); unsigned long sfifo = lpuart32_read(port, UARTFIFO); unsigned long ctrl = lpuart32_read(port, UARTCTRL); if (sport->dma_tx_in_progress) return 0; /* * LPUART Transmission Complete Flag may never be set while queuing a break * character, so avoid checking for transmission complete when UARTCTRL_SBK * is asserted. */ if ((stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT) || ctrl & UARTCTRL_SBK) return TIOCSER_TEMT; return 0; } static void lpuart_txint(struct lpuart_port *sport) { unsigned long flags; spin_lock_irqsave(&sport->port.lock, flags); lpuart_transmit_buffer(sport); spin_unlock_irqrestore(&sport->port.lock, flags); } static void lpuart_rxint(struct lpuart_port *sport) { unsigned int flg, ignored = 0, overrun = 0; struct tty_port *port = &sport->port.state->port; unsigned long flags; unsigned char rx, sr; spin_lock_irqsave(&sport->port.lock, flags); while (!(readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXEMPT)) { flg = TTY_NORMAL; sport->port.icount.rx++; /* * to clear the FE, OR, NF, FE, PE flags, * read SR1 then read DR */ sr = readb(sport->port.membase + UARTSR1); rx = readb(sport->port.membase + UARTDR); if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx)) continue; if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) { if (sr & UARTSR1_PE) sport->port.icount.parity++; else if (sr & UARTSR1_FE) sport->port.icount.frame++; if (sr & UARTSR1_OR) overrun++; if (sr & sport->port.ignore_status_mask) { if (++ignored > 100) goto out; continue; } sr &= sport->port.read_status_mask; if (sr & UARTSR1_PE) flg = TTY_PARITY; else if (sr & UARTSR1_FE) flg = TTY_FRAME; if (sr & UARTSR1_OR) flg = TTY_OVERRUN; sport->port.sysrq = 0; } tty_insert_flip_char(port, rx, flg); } out: if (overrun) { sport->port.icount.overrun += overrun; /* * Overruns cause FIFO pointers to become missaligned. * Flushing the receive FIFO reinitializes the pointers. */ writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); writeb(UARTSFIFO_RXOF, sport->port.membase + UARTSFIFO); } spin_unlock_irqrestore(&sport->port.lock, flags); tty_flip_buffer_push(port); } static void lpuart32_txint(struct lpuart_port *sport) { unsigned long flags; spin_lock_irqsave(&sport->port.lock, flags); lpuart32_transmit_buffer(sport); spin_unlock_irqrestore(&sport->port.lock, flags); } static void lpuart32_rxint(struct lpuart_port *sport) { unsigned int flg, ignored = 0; struct tty_port *port = &sport->port.state->port; unsigned long flags; unsigned long rx, sr; spin_lock_irqsave(&sport->port.lock, flags); while (!(lpuart32_read(&sport->port, UARTFIFO) & UARTFIFO_RXEMPT)) { flg = TTY_NORMAL; sport->port.icount.rx++; /* * to clear the FE, OR, NF, FE, PE flags, * read STAT then read DATA reg */ sr = lpuart32_read(&sport->port, UARTSTAT); rx = lpuart32_read(&sport->port, UARTDATA); rx &= 0x3ff; if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx)) continue; if (sr & (UARTSTAT_PE | UARTSTAT_OR | UARTSTAT_FE)) { if (sr & UARTSTAT_PE) sport->port.icount.parity++; else if (sr & UARTSTAT_FE) sport->port.icount.frame++; if (sr & UARTSTAT_OR) sport->port.icount.overrun++; if (sr & sport->port.ignore_status_mask) { if (++ignored > 100) goto out; continue; } sr &= sport->port.read_status_mask; if (sr & UARTSTAT_PE) flg = TTY_PARITY; else if (sr & UARTSTAT_FE) flg = TTY_FRAME; if (sr & UARTSTAT_OR) flg = TTY_OVERRUN; sport->port.sysrq = 0; } tty_insert_flip_char(port, rx, flg); } out: spin_unlock_irqrestore(&sport->port.lock, flags); tty_flip_buffer_push(port); } static irqreturn_t lpuart_int(int irq, void *dev_id) { struct lpuart_port *sport = dev_id; unsigned char sts; sts = readb(sport->port.membase + UARTSR1); /* SysRq, using dma, check for linebreak by framing err. */ if (sts & UARTSR1_FE && sport->lpuart_dma_rx_use) { readb(sport->port.membase + UARTDR); uart_handle_break(&sport->port); /* linebreak produces some garbage, removing it */ writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); return IRQ_HANDLED; } if (sts & UARTSR1_RDRF && !sport->lpuart_dma_rx_use) lpuart_rxint(sport); if (sts & UARTSR1_TDRE && !sport->lpuart_dma_tx_use) lpuart_txint(sport); return IRQ_HANDLED; } static irqreturn_t lpuart32_int(int irq, void *dev_id) { struct lpuart_port *sport = dev_id; unsigned long sts, rxcount; sts = lpuart32_read(&sport->port, UARTSTAT); rxcount = lpuart32_read(&sport->port, UARTWATER); rxcount = rxcount >> UARTWATER_RXCNT_OFF; if ((sts & UARTSTAT_RDRF || rxcount > 0) && !sport->lpuart_dma_rx_use) lpuart32_rxint(sport); if ((sts & UARTSTAT_TDRE) && !sport->lpuart_dma_tx_use) lpuart32_txint(sport); lpuart32_write(&sport->port, sts, UARTSTAT); return IRQ_HANDLED; } static inline void lpuart_handle_sysrq_chars(struct uart_port *port, unsigned char *p, int count) { while (count--) { if (*p && uart_handle_sysrq_char(port, *p)) return; p++; } } static void lpuart_handle_sysrq(struct lpuart_port *sport) { struct circ_buf *ring = &sport->rx_ring; int count; if (ring->head < ring->tail) { count = sport->rx_sgl.length - ring->tail; lpuart_handle_sysrq_chars(&sport->port, ring->buf + ring->tail, count); ring->tail = 0; } if (ring->head > ring->tail) { count = ring->head - ring->tail; lpuart_handle_sysrq_chars(&sport->port, ring->buf + ring->tail, count); ring->tail = ring->head; } } static void lpuart_copy_rx_to_tty(struct lpuart_port *sport) { struct tty_port *port = &sport->port.state->port; struct dma_tx_state state; enum dma_status dmastat; struct dma_chan *chan = sport->dma_rx_chan; struct circ_buf *ring = &sport->rx_ring; unsigned long flags; int count = 0; if (lpuart_is_32(sport)) { unsigned long sr = lpuart32_read(&sport->port, UARTSTAT); if (sr & (UARTSTAT_PE | UARTSTAT_FE)) { /* Clear the error flags */ lpuart32_write(&sport->port, sr, UARTSTAT); if (sr & UARTSTAT_PE) sport->port.icount.parity++; else if (sr & UARTSTAT_FE) sport->port.icount.frame++; } } else { unsigned char sr = readb(sport->port.membase + UARTSR1); if (sr & (UARTSR1_PE | UARTSR1_FE)) { unsigned char cr2; /* Disable receiver during this operation... */ cr2 = readb(sport->port.membase + UARTCR2); cr2 &= ~UARTCR2_RE; writeb(cr2, sport->port.membase + UARTCR2); /* Read DR to clear the error flags */ readb(sport->port.membase + UARTDR); if (sr & UARTSR1_PE) sport->port.icount.parity++; else if (sr & UARTSR1_FE) sport->port.icount.frame++; /* * At this point parity/framing error is * cleared However, since the DMA already read * the data register and we had to read it * again after reading the status register to * properly clear the flags, the FIFO actually * underflowed... This requires a clearing of * the FIFO... */ if (readb(sport->port.membase + UARTSFIFO) & UARTSFIFO_RXUF) { writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO); writeb(UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); } cr2 |= UARTCR2_RE; writeb(cr2, sport->port.membase + UARTCR2); } } async_tx_ack(sport->dma_rx_desc); spin_lock_irqsave(&sport->port.lock, flags); dmastat = dmaengine_tx_status(chan, sport->dma_rx_cookie, &state); if (dmastat == DMA_ERROR) { dev_err(sport->port.dev, "Rx DMA transfer failed!\n"); spin_unlock_irqrestore(&sport->port.lock, flags); return; } /* CPU claims ownership of RX DMA buffer */ dma_sync_sg_for_cpu(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); /* * ring->head points to the end of data already written by the DMA. * ring->tail points to the beginning of data to be read by the * framework. * The current transfer size should not be larger than the dma buffer * length. */ ring->head = sport->rx_sgl.length - state.residue; BUG_ON(ring->head > sport->rx_sgl.length); /* * Silent handling of keys pressed in the sysrq timeframe */ if (sport->port.sysrq) { lpuart_handle_sysrq(sport); goto exit; } /* * At this point ring->head may point to the first byte right after the * last byte of the dma buffer: * 0 <= ring->head <= sport->rx_sgl.length * * However ring->tail must always points inside the dma buffer: * 0 <= ring->tail <= sport->rx_sgl.length - 1 * * Since we use a ring buffer, we have to handle the case * where head is lower than tail. In such a case, we first read from * tail to the end of the buffer then reset tail. */ if (ring->head < ring->tail) { count = sport->rx_sgl.length - ring->tail; tty_insert_flip_string(port, ring->buf + ring->tail, count); ring->tail = 0; sport->port.icount.rx += count; } /* Finally we read data from tail to head */ if (ring->tail < ring->head) { count = ring->head - ring->tail; tty_insert_flip_string(port, ring->buf + ring->tail, count); /* Wrap ring->head if needed */ if (ring->head >= sport->rx_sgl.length) ring->head = 0; ring->tail = ring->head; sport->port.icount.rx += count; } exit: dma_sync_sg_for_device(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); spin_unlock_irqrestore(&sport->port.lock, flags); tty_flip_buffer_push(port); mod_timer(&sport->lpuart_timer, jiffies + sport->dma_rx_timeout); } static void lpuart_dma_rx_complete(void *arg) { struct lpuart_port *sport = arg; lpuart_copy_rx_to_tty(sport); } static void lpuart_timer_func(struct timer_list *t) { struct lpuart_port *sport = from_timer(sport, t, lpuart_timer); lpuart_copy_rx_to_tty(sport); } static inline int lpuart_start_rx_dma(struct lpuart_port *sport) { struct dma_slave_config dma_rx_sconfig = {}; struct circ_buf *ring = &sport->rx_ring; int ret, nent; int bits, baud; struct tty_port *port = &sport->port.state->port; struct tty_struct *tty = port->tty; struct ktermios *termios = &tty->termios; struct dma_chan *chan = sport->dma_rx_chan; baud = tty_get_baud_rate(tty); bits = (termios->c_cflag & CSIZE) == CS7 ? 9 : 10; if (termios->c_cflag & PARENB) bits++; /* * Calculate length of one DMA buffer size to keep latency below * 10ms at any baud rate. */ sport->rx_dma_rng_buf_len = (DMA_RX_TIMEOUT * baud / bits / 1000) * 2; sport->rx_dma_rng_buf_len = (1 << fls(sport->rx_dma_rng_buf_len)); if (sport->rx_dma_rng_buf_len < 16) sport->rx_dma_rng_buf_len = 16; ring->buf = kzalloc(sport->rx_dma_rng_buf_len, GFP_ATOMIC); if (!ring->buf) return -ENOMEM; sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len); nent = dma_map_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); if (!nent) { dev_err(sport->port.dev, "DMA Rx mapping error\n"); return -EINVAL; } dma_rx_sconfig.src_addr = lpuart_dma_datareg_addr(sport); dma_rx_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; dma_rx_sconfig.src_maxburst = 1; dma_rx_sconfig.direction = DMA_DEV_TO_MEM; ret = dmaengine_slave_config(chan, &dma_rx_sconfig); if (ret < 0) { dev_err(sport->port.dev, "DMA Rx slave config failed, err = %d\n", ret); return ret; } sport->dma_rx_desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(&sport->rx_sgl), sport->rx_sgl.length, sport->rx_sgl.length / 2, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); if (!sport->dma_rx_desc) { dev_err(sport->port.dev, "Cannot prepare cyclic DMA\n"); return -EFAULT; } sport->dma_rx_desc->callback = lpuart_dma_rx_complete; sport->dma_rx_desc->callback_param = sport; sport->dma_rx_cookie = dmaengine_submit(sport->dma_rx_desc); dma_async_issue_pending(chan); if (lpuart_is_32(sport)) { unsigned long temp = lpuart32_read(&sport->port, UARTBAUD); lpuart32_write(&sport->port, temp | UARTBAUD_RDMAE, UARTBAUD); } else { writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_RDMAS, sport->port.membase + UARTCR5); } return 0; } static void lpuart_dma_rx_free(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); struct dma_chan *chan = sport->dma_rx_chan; dmaengine_terminate_all(chan); del_timer_sync(&sport->lpuart_timer); dma_unmap_sg(chan->device->dev, &sport->rx_sgl, 1, DMA_FROM_DEVICE); kfree(sport->rx_ring.buf); sport->rx_ring.tail = 0; sport->rx_ring.head = 0; sport->dma_rx_desc = NULL; sport->dma_rx_cookie = -EINVAL; } static int lpuart_config_rs485(struct uart_port *port, struct serial_rs485 *rs485) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); u8 modem = readb(sport->port.membase + UARTMODEM) & ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE); writeb(modem, sport->port.membase + UARTMODEM); /* clear unsupported configurations */ rs485->delay_rts_before_send = 0; rs485->delay_rts_after_send = 0; rs485->flags &= ~SER_RS485_RX_DURING_TX; if (rs485->flags & SER_RS485_ENABLED) { /* Enable auto RS-485 RTS mode */ modem |= UARTMODEM_TXRTSE; /* * RTS needs to be logic HIGH either during transfer _or_ after * transfer, other variants are not supported by the hardware. */ if (!(rs485->flags & (SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND))) rs485->flags |= SER_RS485_RTS_ON_SEND; if (rs485->flags & SER_RS485_RTS_ON_SEND && rs485->flags & SER_RS485_RTS_AFTER_SEND) rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; /* * The hardware defaults to RTS logic HIGH while transfer. * Switch polarity in case RTS shall be logic HIGH * after transfer. * Note: UART is assumed to be active high. */ if (rs485->flags & SER_RS485_RTS_ON_SEND) modem &= ~UARTMODEM_TXRTSPOL; else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) modem |= UARTMODEM_TXRTSPOL; } /* Store the new configuration */ sport->port.rs485 = *rs485; writeb(modem, sport->port.membase + UARTMODEM); return 0; } static int lpuart32_config_rs485(struct uart_port *port, struct serial_rs485 *rs485) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long modem = lpuart32_read(&sport->port, UARTMODIR) & ~(UARTMODEM_TXRTSPOL | UARTMODEM_TXRTSE); lpuart32_write(&sport->port, modem, UARTMODIR); /* clear unsupported configurations */ rs485->delay_rts_before_send = 0; rs485->delay_rts_after_send = 0; rs485->flags &= ~SER_RS485_RX_DURING_TX; if (rs485->flags & SER_RS485_ENABLED) { /* Enable auto RS-485 RTS mode */ modem |= UARTMODEM_TXRTSE; /* * RTS needs to be logic HIGH either during transfer _or_ after * transfer, other variants are not supported by the hardware. */ if (!(rs485->flags & (SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND))) rs485->flags |= SER_RS485_RTS_ON_SEND; if (rs485->flags & SER_RS485_RTS_ON_SEND && rs485->flags & SER_RS485_RTS_AFTER_SEND) rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; /* * The hardware defaults to RTS logic HIGH while transfer. * Switch polarity in case RTS shall be logic HIGH * after transfer. * Note: UART is assumed to be active high. */ if (rs485->flags & SER_RS485_RTS_ON_SEND) modem |= UARTMODEM_TXRTSPOL; else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) modem &= ~UARTMODEM_TXRTSPOL; } /* Store the new configuration */ sport->port.rs485 = *rs485; lpuart32_write(&sport->port, modem, UARTMODIR); return 0; } static unsigned int lpuart_get_mctrl(struct uart_port *port) { unsigned int temp = 0; unsigned char reg; reg = readb(port->membase + UARTMODEM); if (reg & UARTMODEM_TXCTSE) temp |= TIOCM_CTS; if (reg & UARTMODEM_RXRTSE) temp |= TIOCM_RTS; return temp; } static unsigned int lpuart32_get_mctrl(struct uart_port *port) { return 0; } static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl) { unsigned char temp; struct lpuart_port *sport = container_of(port, struct lpuart_port, port); /* Make sure RXRTSE bit is not set when RS485 is enabled */ if (!(sport->port.rs485.flags & SER_RS485_ENABLED)) { temp = readb(sport->port.membase + UARTMODEM) & ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE); if (mctrl & TIOCM_RTS) temp |= UARTMODEM_RXRTSE; if (mctrl & TIOCM_CTS) temp |= UARTMODEM_TXCTSE; writeb(temp, port->membase + UARTMODEM); } } static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl) { } static void lpuart_break_ctl(struct uart_port *port, int break_state) { unsigned char temp; temp = readb(port->membase + UARTCR2) & ~UARTCR2_SBK; if (break_state != 0) temp |= UARTCR2_SBK; writeb(temp, port->membase + UARTCR2); } static void lpuart32_break_ctl(struct uart_port *port, int break_state) { unsigned long temp; temp = lpuart32_read(port, UARTCTRL); /* * LPUART IP now has two known bugs, one is CTS has higher priority than the * break signal, which causes the break signal sending through UARTCTRL_SBK * may impacted by the CTS input if the HW flow control is enabled. It * exists on all platforms we support in this driver. * Another bug is i.MX8QM LPUART may have an additional break character * being sent after SBK was cleared. * To avoid above two bugs, we use Transmit Data Inversion function to send * the break signal instead of UARTCTRL_SBK. */ if (break_state != 0) { /* * Disable the transmitter to prevent any data from being sent out * during break, then invert the TX line to send break. */ temp &= ~UARTCTRL_TE; lpuart32_write(port, temp, UARTCTRL); temp |= UARTCTRL_TXINV; lpuart32_write(port, temp, UARTCTRL); } else { /* Disable the TXINV to turn off break and re-enable transmitter. */ temp &= ~UARTCTRL_TXINV; lpuart32_write(port, temp, UARTCTRL); temp |= UARTCTRL_TE; lpuart32_write(port, temp, UARTCTRL); } } static void lpuart_setup_watermark(struct lpuart_port *sport) { unsigned char val, cr2; unsigned char cr2_saved; cr2 = readb(sport->port.membase + UARTCR2); cr2_saved = cr2; cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_TE | UARTCR2_RIE | UARTCR2_RE); writeb(cr2, sport->port.membase + UARTCR2); val = readb(sport->port.membase + UARTPFIFO); writeb(val | UARTPFIFO_TXFE | UARTPFIFO_RXFE, sport->port.membase + UARTPFIFO); /* flush Tx and Rx FIFO */ writeb(UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH, sport->port.membase + UARTCFIFO); /* explicitly clear RDRF */ if (readb(sport->port.membase + UARTSR1) & UARTSR1_RDRF) { readb(sport->port.membase + UARTDR); writeb(UARTSFIFO_RXUF, sport->port.membase + UARTSFIFO); } writeb(0, sport->port.membase + UARTTWFIFO); writeb(1, sport->port.membase + UARTRWFIFO); /* Restore cr2 */ writeb(cr2_saved, sport->port.membase + UARTCR2); } static void lpuart_setup_watermark_enable(struct lpuart_port *sport) { unsigned char cr2; lpuart_setup_watermark(sport); cr2 = readb(sport->port.membase + UARTCR2); cr2 |= UARTCR2_RIE | UARTCR2_RE | UARTCR2_TE; writeb(cr2, sport->port.membase + UARTCR2); } static void lpuart32_setup_watermark(struct lpuart_port *sport) { unsigned long val, ctrl; unsigned long ctrl_saved; ctrl = lpuart32_read(&sport->port, UARTCTRL); ctrl_saved = ctrl; ctrl &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_TE | UARTCTRL_RIE | UARTCTRL_RE); lpuart32_write(&sport->port, ctrl, UARTCTRL); /* enable FIFO mode */ val = lpuart32_read(&sport->port, UARTFIFO); val |= UARTFIFO_TXFE | UARTFIFO_RXFE; val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH; lpuart32_write(&sport->port, val, UARTFIFO); /* set the watermark */ val = (0x1 << UARTWATER_RXWATER_OFF) | (0x0 << UARTWATER_TXWATER_OFF); lpuart32_write(&sport->port, val, UARTWATER); /* Restore cr2 */ lpuart32_write(&sport->port, ctrl_saved, UARTCTRL); } static void lpuart32_setup_watermark_enable(struct lpuart_port *sport) { u32 temp; lpuart32_setup_watermark(sport); temp = lpuart32_read(&sport->port, UARTCTRL); temp |= UARTCTRL_RE | UARTCTRL_TE | UARTCTRL_ILIE; lpuart32_write(&sport->port, temp, UARTCTRL); } static void rx_dma_timer_init(struct lpuart_port *sport) { timer_setup(&sport->lpuart_timer, lpuart_timer_func, 0); sport->lpuart_timer.expires = jiffies + sport->dma_rx_timeout; add_timer(&sport->lpuart_timer); } static void lpuart_request_dma(struct lpuart_port *sport) { sport->dma_tx_chan = dma_request_chan(sport->port.dev, "tx"); if (IS_ERR(sport->dma_tx_chan)) { dev_dbg_once(sport->port.dev, "DMA tx channel request failed, operating without tx DMA (%ld)\n", PTR_ERR(sport->dma_tx_chan)); sport->dma_tx_chan = NULL; } sport->dma_rx_chan = dma_request_chan(sport->port.dev, "rx"); if (IS_ERR(sport->dma_rx_chan)) { dev_dbg_once(sport->port.dev, "DMA rx channel request failed, operating without rx DMA (%ld)\n", PTR_ERR(sport->dma_rx_chan)); sport->dma_rx_chan = NULL; } } static void lpuart_tx_dma_startup(struct lpuart_port *sport) { u32 uartbaud; int ret; if (uart_console(&sport->port)) goto err; if (!sport->dma_tx_chan) goto err; ret = lpuart_dma_tx_request(&sport->port); if (ret) goto err; init_waitqueue_head(&sport->dma_wait); sport->lpuart_dma_tx_use = true; if (lpuart_is_32(sport)) { uartbaud = lpuart32_read(&sport->port, UARTBAUD); lpuart32_write(&sport->port, uartbaud | UARTBAUD_TDMAE, UARTBAUD); } else { writeb(readb(sport->port.membase + UARTCR5) | UARTCR5_TDMAS, sport->port.membase + UARTCR5); } return; err: sport->lpuart_dma_tx_use = false; } static void lpuart_rx_dma_startup(struct lpuart_port *sport) { int ret; unsigned char cr3; if (uart_console(&sport->port)) goto err; if (!sport->dma_rx_chan) goto err; ret = lpuart_start_rx_dma(sport); if (ret) goto err; /* set Rx DMA timeout */ sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT); if (!sport->dma_rx_timeout) sport->dma_rx_timeout = 1; sport->lpuart_dma_rx_use = true; rx_dma_timer_init(sport); if (sport->port.has_sysrq && !lpuart_is_32(sport)) { cr3 = readb(sport->port.membase + UARTCR3); cr3 |= UARTCR3_FEIE; writeb(cr3, sport->port.membase + UARTCR3); } return; err: sport->lpuart_dma_rx_use = false; } static int lpuart_startup(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long flags; unsigned char temp; /* determine FIFO size and enable FIFO mode */ temp = readb(sport->port.membase + UARTPFIFO); sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_TXSIZE_OFF) & UARTPFIFO_FIFOSIZE_MASK); sport->port.fifosize = sport->txfifo_size; sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTPFIFO_RXSIZE_OFF) & UARTPFIFO_FIFOSIZE_MASK); lpuart_request_dma(sport); spin_lock_irqsave(&sport->port.lock, flags); lpuart_setup_watermark_enable(sport); lpuart_rx_dma_startup(sport); lpuart_tx_dma_startup(sport); spin_unlock_irqrestore(&sport->port.lock, flags); return 0; } static void lpuart32_configure(struct lpuart_port *sport) { unsigned long temp; if (sport->lpuart_dma_rx_use) { /* RXWATER must be 0 */ temp = lpuart32_read(&sport->port, UARTWATER); temp &= ~(UARTWATER_WATER_MASK << UARTWATER_RXWATER_OFF); lpuart32_write(&sport->port, temp, UARTWATER); } temp = lpuart32_read(&sport->port, UARTCTRL); if (!sport->lpuart_dma_rx_use) temp |= UARTCTRL_RIE; if (!sport->lpuart_dma_tx_use) temp |= UARTCTRL_TIE; lpuart32_write(&sport->port, temp, UARTCTRL); } static int lpuart32_startup(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long flags; unsigned long temp; /* determine FIFO size */ temp = lpuart32_read(&sport->port, UARTFIFO); sport->txfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_TXSIZE_OFF) & UARTFIFO_FIFOSIZE_MASK); sport->port.fifosize = sport->txfifo_size; sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_RXSIZE_OFF) & UARTFIFO_FIFOSIZE_MASK); /* * The LS1021A and LS1028A have a fixed FIFO depth of 16 words. * Although they support the RX/TXSIZE fields, their encoding is * different. Eg the reference manual states 0b101 is 16 words. */ if (is_layerscape_lpuart(sport)) { sport->rxfifo_size = 16; sport->txfifo_size = 16; sport->port.fifosize = sport->txfifo_size; } lpuart_request_dma(sport); spin_lock_irqsave(&sport->port.lock, flags); lpuart32_setup_watermark_enable(sport); lpuart_rx_dma_startup(sport); lpuart_tx_dma_startup(sport); lpuart32_configure(sport); spin_unlock_irqrestore(&sport->port.lock, flags); return 0; } static void lpuart_dma_shutdown(struct lpuart_port *sport) { if (sport->lpuart_dma_rx_use) { lpuart_dma_rx_free(&sport->port); sport->lpuart_dma_rx_use = false; } if (sport->lpuart_dma_tx_use) { if (wait_event_interruptible(sport->dma_wait, !sport->dma_tx_in_progress) != false) { sport->dma_tx_in_progress = false; dmaengine_terminate_all(sport->dma_tx_chan); } sport->lpuart_dma_tx_use = false; } if (sport->dma_tx_chan) dma_release_channel(sport->dma_tx_chan); if (sport->dma_rx_chan) dma_release_channel(sport->dma_rx_chan); } static void lpuart_shutdown(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned char temp; unsigned long flags; spin_lock_irqsave(&port->lock, flags); /* disable Rx/Tx and interrupts */ temp = readb(port->membase + UARTCR2); temp &= ~(UARTCR2_TE | UARTCR2_RE | UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE); writeb(temp, port->membase + UARTCR2); spin_unlock_irqrestore(&port->lock, flags); lpuart_dma_shutdown(sport); } static void lpuart32_shutdown(struct uart_port *port) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long temp; unsigned long flags; spin_lock_irqsave(&port->lock, flags); /* disable Rx/Tx and interrupts */ temp = lpuart32_read(port, UARTCTRL); temp &= ~(UARTCTRL_TE | UARTCTRL_RE | UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE); lpuart32_write(port, temp, UARTCTRL); spin_unlock_irqrestore(&port->lock, flags); lpuart_dma_shutdown(sport); } static void lpuart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long flags; unsigned char cr1, old_cr1, old_cr2, cr3, cr4, bdh, modem; unsigned int baud; unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; unsigned int sbr, brfa; cr1 = old_cr1 = readb(sport->port.membase + UARTCR1); old_cr2 = readb(sport->port.membase + UARTCR2); cr3 = readb(sport->port.membase + UARTCR3); cr4 = readb(sport->port.membase + UARTCR4); bdh = readb(sport->port.membase + UARTBDH); modem = readb(sport->port.membase + UARTMODEM); /* * only support CS8 and CS7, and for CS7 must enable PE. * supported mode: * - (7,e/o,1) * - (8,n,1) * - (8,m/s,1) * - (8,e/o,1) */ while ((termios->c_cflag & CSIZE) != CS8 && (termios->c_cflag & CSIZE) != CS7) { termios->c_cflag &= ~CSIZE; termios->c_cflag |= old_csize; old_csize = CS8; } if ((termios->c_cflag & CSIZE) == CS8 || (termios->c_cflag & CSIZE) == CS7) cr1 = old_cr1 & ~UARTCR1_M; if (termios->c_cflag & CMSPAR) { if ((termios->c_cflag & CSIZE) != CS8) { termios->c_cflag &= ~CSIZE; termios->c_cflag |= CS8; } cr1 |= UARTCR1_M; } /* * When auto RS-485 RTS mode is enabled, * hardware flow control need to be disabled. */ if (sport->port.rs485.flags & SER_RS485_ENABLED) termios->c_cflag &= ~CRTSCTS; if (termios->c_cflag & CRTSCTS) modem |= UARTMODEM_RXRTSE | UARTMODEM_TXCTSE; else modem &= ~(UARTMODEM_RXRTSE | UARTMODEM_TXCTSE); termios->c_cflag &= ~CSTOPB; /* parity must be enabled when CS7 to match 8-bits format */ if ((termios->c_cflag & CSIZE) == CS7) termios->c_cflag |= PARENB; if (termios->c_cflag & PARENB) { if (termios->c_cflag & CMSPAR) { cr1 &= ~UARTCR1_PE; if (termios->c_cflag & PARODD) cr3 |= UARTCR3_T8; else cr3 &= ~UARTCR3_T8; } else { cr1 |= UARTCR1_PE; if ((termios->c_cflag & CSIZE) == CS8) cr1 |= UARTCR1_M; if (termios->c_cflag & PARODD) cr1 |= UARTCR1_PT; else cr1 &= ~UARTCR1_PT; } } else { cr1 &= ~UARTCR1_PE; } /* ask the core to calculate the divisor */ baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16); /* * Need to update the Ring buffer length according to the selected * baud rate and restart Rx DMA path. * * Since timer function acqures sport->port.lock, need to stop before * acquring same lock because otherwise del_timer_sync() can deadlock. */ if (old && sport->lpuart_dma_rx_use) lpuart_dma_rx_free(&sport->port); spin_lock_irqsave(&sport->port.lock, flags); sport->port.read_status_mask = 0; if (termios->c_iflag & INPCK) sport->port.read_status_mask |= UARTSR1_FE | UARTSR1_PE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) sport->port.read_status_mask |= UARTSR1_FE; /* characters to ignore */ sport->port.ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) sport->port.ignore_status_mask |= UARTSR1_PE; if (termios->c_iflag & IGNBRK) { sport->port.ignore_status_mask |= UARTSR1_FE; /* * if we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) sport->port.ignore_status_mask |= UARTSR1_OR; } /* update the per-port timeout */ uart_update_timeout(port, termios->c_cflag, baud); /* wait transmit engin complete */ lpuart_wait_bit_set(&sport->port, UARTSR1, UARTSR1_TC); /* disable transmit and receive */ writeb(old_cr2 & ~(UARTCR2_TE | UARTCR2_RE), sport->port.membase + UARTCR2); sbr = sport->port.uartclk / (16 * baud); brfa = ((sport->port.uartclk - (16 * sbr * baud)) * 2) / baud; bdh &= ~UARTBDH_SBR_MASK; bdh |= (sbr >> 8) & 0x1F; cr4 &= ~UARTCR4_BRFA_MASK; brfa &= UARTCR4_BRFA_MASK; writeb(cr4 | brfa, sport->port.membase + UARTCR4); writeb(bdh, sport->port.membase + UARTBDH); writeb(sbr & 0xFF, sport->port.membase + UARTBDL); writeb(cr3, sport->port.membase + UARTCR3); writeb(cr1, sport->port.membase + UARTCR1); writeb(modem, sport->port.membase + UARTMODEM); /* restore control register */ writeb(old_cr2, sport->port.membase + UARTCR2); if (old && sport->lpuart_dma_rx_use) { if (!lpuart_start_rx_dma(sport)) rx_dma_timer_init(sport); else sport->lpuart_dma_rx_use = false; } spin_unlock_irqrestore(&sport->port.lock, flags); } static void __lpuart32_serial_setbrg(struct uart_port *port, unsigned int baudrate, bool use_rx_dma, bool use_tx_dma) { u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp; u32 clk = port->uartclk; /* * The idea is to use the best OSR (over-sampling rate) possible. * Note, OSR is typically hard-set to 16 in other LPUART instantiations. * Loop to find the best OSR value possible, one that generates minimum * baud_diff iterate through the rest of the supported values of OSR. * * Calculation Formula: * Baud Rate = baud clock / ((OSR+1) × SBR) */ baud_diff = baudrate; osr = 0; sbr = 0; for (tmp_osr = 4; tmp_osr <= 32; tmp_osr++) { /* calculate the temporary sbr value */ tmp_sbr = (clk / (baudrate * tmp_osr)); if (tmp_sbr == 0) tmp_sbr = 1; /* * calculate the baud rate difference based on the temporary * osr and sbr values */ tmp_diff = clk / (tmp_osr * tmp_sbr) - baudrate; /* select best values between sbr and sbr+1 */ tmp = clk / (tmp_osr * (tmp_sbr + 1)); if (tmp_diff > (baudrate - tmp)) { tmp_diff = baudrate - tmp; tmp_sbr++; } if (tmp_sbr > UARTBAUD_SBR_MASK) continue; if (tmp_diff <= baud_diff) { baud_diff = tmp_diff; osr = tmp_osr; sbr = tmp_sbr; if (!baud_diff) break; } } /* handle buadrate outside acceptable rate */ if (baud_diff > ((baudrate / 100) * 3)) dev_warn(port->dev, "unacceptable baud rate difference of more than 3%%\n"); tmp = lpuart32_read(port, UARTBAUD); if ((osr > 3) && (osr < 8)) tmp |= UARTBAUD_BOTHEDGE; tmp &= ~(UARTBAUD_OSR_MASK << UARTBAUD_OSR_SHIFT); tmp |= ((osr-1) & UARTBAUD_OSR_MASK) << UARTBAUD_OSR_SHIFT; tmp &= ~UARTBAUD_SBR_MASK; tmp |= sbr & UARTBAUD_SBR_MASK; if (!use_rx_dma) tmp &= ~UARTBAUD_RDMAE; if (!use_tx_dma) tmp &= ~UARTBAUD_TDMAE; lpuart32_write(port, tmp, UARTBAUD); } static void lpuart32_serial_setbrg(struct lpuart_port *sport, unsigned int baudrate) { __lpuart32_serial_setbrg(&sport->port, baudrate, sport->lpuart_dma_rx_use, sport->lpuart_dma_tx_use); } static void lpuart32_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct lpuart_port *sport = container_of(port, struct lpuart_port, port); unsigned long flags; unsigned long ctrl, old_ctrl, modem; unsigned int baud; unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; ctrl = old_ctrl = lpuart32_read(&sport->port, UARTCTRL); modem = lpuart32_read(&sport->port, UARTMODIR); /* * only support CS8 and CS7, and for CS7 must enable PE. * supported mode: * - (7,e/o,1) * - (8,n,1) * - (8,m/s,1) * - (8,e/o,1) */ while ((termios->c_cflag & CSIZE) != CS8 && (termios->c_cflag & CSIZE) != CS7) { termios->c_cflag &= ~CSIZE; termios->c_cflag |= old_csize; old_csize = CS8; } if ((termios->c_cflag & CSIZE) == CS8 || (termios->c_cflag & CSIZE) == CS7) ctrl = old_ctrl & ~UARTCTRL_M; if (termios->c_cflag & CMSPAR) { if ((termios->c_cflag & CSIZE) != CS8) { termios->c_cflag &= ~CSIZE; termios->c_cflag |= CS8; } ctrl |= UARTCTRL_M; } /* * When auto RS-485 RTS mode is enabled, * hardware flow control need to be disabled. */ if (sport->port.rs485.flags & SER_RS485_ENABLED) termios->c_cflag &= ~CRTSCTS; if (termios->c_cflag & CRTSCTS) { modem |= (UARTMODIR_RXRTSE | UARTMODIR_TXCTSE); } else { termios->c_cflag &= ~CRTSCTS; modem &= ~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE); } if (termios->c_cflag & CSTOPB) termios->c_cflag &= ~CSTOPB; /* parity must be enabled when CS7 to match 8-bits format */ if ((termios->c_cflag & CSIZE) == CS7) termios->c_cflag |= PARENB; if ((termios->c_cflag & PARENB)) { if (termios->c_cflag & CMSPAR) { ctrl &= ~UARTCTRL_PE; ctrl |= UARTCTRL_M; } else { ctrl |= UARTCTRL_PE; if ((termios->c_cflag & CSIZE) == CS8) ctrl |= UARTCTRL_M; if (termios->c_cflag & PARODD) ctrl |= UARTCTRL_PT; else ctrl &= ~UARTCTRL_PT; } } else { ctrl &= ~UARTCTRL_PE; } /* ask the core to calculate the divisor */ baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 4); /* * Need to update the Ring buffer length according to the selected * baud rate and restart Rx DMA path. * * Since timer function acqures sport->port.lock, need to stop before * acquring same lock because otherwise del_timer_sync() can deadlock. */ if (old && sport->lpuart_dma_rx_use) lpuart_dma_rx_free(&sport->port); spin_lock_irqsave(&sport->port.lock, flags); sport->port.read_status_mask = 0; if (termios->c_iflag & INPCK) sport->port.read_status_mask |= UARTSTAT_FE | UARTSTAT_PE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) sport->port.read_status_mask |= UARTSTAT_FE; /* characters to ignore */ sport->port.ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) sport->port.ignore_status_mask |= UARTSTAT_PE; if (termios->c_iflag & IGNBRK) { sport->port.ignore_status_mask |= UARTSTAT_FE; /* * if we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) sport->port.ignore_status_mask |= UARTSTAT_OR; } /* update the per-port timeout */ uart_update_timeout(port, termios->c_cflag, baud); /* * LPUART Transmission Complete Flag may never be set while queuing a break * character, so skip waiting for transmission complete when UARTCTRL_SBK is * asserted. */ if (!(old_ctrl & UARTCTRL_SBK)) { lpuart32_write(&sport->port, 0, UARTMODIR); lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC); } /* disable transmit and receive */ lpuart32_write(&sport->port, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE), UARTCTRL); lpuart32_serial_setbrg(sport, baud); lpuart32_write(&sport->port, modem, UARTMODIR); lpuart32_write(&sport->port, ctrl, UARTCTRL); /* restore control register */ if (old && sport->lpuart_dma_rx_use) { if (!lpuart_start_rx_dma(sport)) rx_dma_timer_init(sport); else sport->lpuart_dma_rx_use = false; } spin_unlock_irqrestore(&sport->port.lock, flags); } static const char *lpuart_type(struct uart_port *port) { return "FSL_LPUART"; } static void lpuart_release_port(struct uart_port *port) { /* nothing to do */ } static int lpuart_request_port(struct uart_port *port) { return 0; } /* configure/autoconfigure the port */ static void lpuart_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) port->type = PORT_LPUART; } static int lpuart_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_LPUART) ret = -EINVAL; if (port->irq != ser->irq) ret = -EINVAL; if (ser->io_type != UPIO_MEM) ret = -EINVAL; if (port->uartclk / 16 != ser->baud_base) ret = -EINVAL; if (port->iobase != ser->port) ret = -EINVAL; if (ser->hub6 != 0) ret = -EINVAL; return ret; } static const struct uart_ops lpuart_pops = { .tx_empty = lpuart_tx_empty, .set_mctrl = lpuart_set_mctrl, .get_mctrl = lpuart_get_mctrl, .stop_tx = lpuart_stop_tx, .start_tx = lpuart_start_tx, .stop_rx = lpuart_stop_rx, .break_ctl = lpuart_break_ctl, .startup = lpuart_startup, .shutdown = lpuart_shutdown, .set_termios = lpuart_set_termios, .type = lpuart_type, .request_port = lpuart_request_port, .release_port = lpuart_release_port, .config_port = lpuart_config_port, .verify_port = lpuart_verify_port, .flush_buffer = lpuart_flush_buffer, #if defined(CONFIG_CONSOLE_POLL) .poll_init = lpuart_poll_init, .poll_get_char = lpuart_poll_get_char, .poll_put_char = lpuart_poll_put_char, #endif }; static const struct uart_ops lpuart32_pops = { .tx_empty = lpuart32_tx_empty, .set_mctrl = lpuart32_set_mctrl, .get_mctrl = lpuart32_get_mctrl, .stop_tx = lpuart32_stop_tx, .start_tx = lpuart32_start_tx, .stop_rx = lpuart32_stop_rx, .break_ctl = lpuart32_break_ctl, .startup = lpuart32_startup, .shutdown = lpuart32_shutdown, .set_termios = lpuart32_set_termios, .type = lpuart_type, .request_port = lpuart_request_port, .release_port = lpuart_release_port, .config_port = lpuart_config_port, .verify_port = lpuart_verify_port, .flush_buffer = lpuart_flush_buffer, #if defined(CONFIG_CONSOLE_POLL) .poll_init = lpuart32_poll_init, .poll_get_char = lpuart32_poll_get_char, .poll_put_char = lpuart32_poll_put_char, #endif }; static struct lpuart_port *lpuart_ports[UART_NR]; #ifdef CONFIG_SERIAL_FSL_LPUART_CONSOLE static void lpuart_console_putchar(struct uart_port *port, int ch) { lpuart_wait_bit_set(port, UARTSR1, UARTSR1_TDRE); writeb(ch, port->membase + UARTDR); } static void lpuart32_console_putchar(struct uart_port *port, int ch) { lpuart32_wait_bit_set(port, UARTSTAT, UARTSTAT_TDRE); lpuart32_write(port, ch, UARTDATA); } static void lpuart_console_write(struct console *co, const char *s, unsigned int count) { struct lpuart_port *sport = lpuart_ports[co->index]; unsigned char old_cr2, cr2; unsigned long flags; int locked = 1; if (sport->port.sysrq || oops_in_progress) locked = spin_trylock_irqsave(&sport->port.lock, flags); else spin_lock_irqsave(&sport->port.lock, flags); /* first save CR2 and then disable interrupts */ cr2 = old_cr2 = readb(sport->port.membase + UARTCR2); cr2 |= UARTCR2_TE | UARTCR2_RE; cr2 &= ~(UARTCR2_TIE | UARTCR2_TCIE | UARTCR2_RIE); writeb(cr2, sport->port.membase + UARTCR2); uart_console_write(&sport->port, s, count, lpuart_console_putchar); /* wait for transmitter finish complete and restore CR2 */ lpuart_wait_bit_set(&sport->port, UARTSR1, UARTSR1_TC); writeb(old_cr2, sport->port.membase + UARTCR2); if (locked) spin_unlock_irqrestore(&sport->port.lock, flags); } static void lpuart32_console_write(struct console *co, const char *s, unsigned int count) { struct lpuart_port *sport = lpuart_ports[co->index]; unsigned long old_cr, cr; unsigned long flags; int locked = 1; if (sport->port.sysrq || oops_in_progress) locked = spin_trylock_irqsave(&sport->port.lock, flags); else spin_lock_irqsave(&sport->port.lock, flags); /* first save CR2 and then disable interrupts */ cr = old_cr = lpuart32_read(&sport->port, UARTCTRL); cr |= UARTCTRL_TE | UARTCTRL_RE; cr &= ~(UARTCTRL_TIE | UARTCTRL_TCIE | UARTCTRL_RIE); lpuart32_write(&sport->port, cr, UARTCTRL); uart_console_write(&sport->port, s, count, lpuart32_console_putchar); /* wait for transmitter finish complete and restore CR2 */ lpuart32_wait_bit_set(&sport->port, UARTSTAT, UARTSTAT_TC); lpuart32_write(&sport->port, old_cr, UARTCTRL); if (locked) spin_unlock_irqrestore(&sport->port.lock, flags); } /* * if the port was already initialised (eg, by a boot loader), * try to determine the current setup. */ static void __init lpuart_console_get_options(struct lpuart_port *sport, int *baud, int *parity, int *bits) { unsigned char cr, bdh, bdl, brfa; unsigned int sbr, uartclk, baud_raw; cr = readb(sport->port.membase + UARTCR2); cr &= UARTCR2_TE | UARTCR2_RE; if (!cr) return; /* ok, the port was enabled */ cr = readb(sport->port.membase + UARTCR1); *parity = 'n'; if (cr & UARTCR1_PE) { if (cr & UARTCR1_PT) *parity = 'o'; else *parity = 'e'; } if (cr & UARTCR1_M) *bits = 9; else *bits = 8; bdh = readb(sport->port.membase + UARTBDH); bdh &= UARTBDH_SBR_MASK; bdl = readb(sport->port.membase + UARTBDL); sbr = bdh; sbr <<= 8; sbr |= bdl; brfa = readb(sport->port.membase + UARTCR4); brfa &= UARTCR4_BRFA_MASK; uartclk = lpuart_get_baud_clk_rate(sport); /* * baud = mod_clk/(16*(sbr[13]+(brfa)/32) */ baud_raw = uartclk / (16 * (sbr + brfa / 32)); if (*baud != baud_raw) dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate" "from %d to %d\n", baud_raw, *baud); } static void __init lpuart32_console_get_options(struct lpuart_port *sport, int *baud, int *parity, int *bits) { unsigned long cr, bd; unsigned int sbr, uartclk, baud_raw; cr = lpuart32_read(&sport->port, UARTCTRL); cr &= UARTCTRL_TE | UARTCTRL_RE; if (!cr) return; /* ok, the port was enabled */ cr = lpuart32_read(&sport->port, UARTCTRL); *parity = 'n'; if (cr & UARTCTRL_PE) { if (cr & UARTCTRL_PT) *parity = 'o'; else *parity = 'e'; } if (cr & UARTCTRL_M) *bits = 9; else *bits = 8; bd = lpuart32_read(&sport->port, UARTBAUD); bd &= UARTBAUD_SBR_MASK; if (!bd) return; sbr = bd; uartclk = lpuart_get_baud_clk_rate(sport); /* * baud = mod_clk/(16*(sbr[13]+(brfa)/32) */ baud_raw = uartclk / (16 * sbr); if (*baud != baud_raw) dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate" "from %d to %d\n", baud_raw, *baud); } static int __init lpuart_console_setup(struct console *co, char *options) { struct lpuart_port *sport; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; /* * check whether an invalid uart number has been specified, and * if so, search for the first available port that does have * console support. */ if (co->index == -1 || co->index >= ARRAY_SIZE(lpuart_ports)) co->index = 0; sport = lpuart_ports[co->index]; if (sport == NULL) return -ENODEV; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else if (lpuart_is_32(sport)) lpuart32_console_get_options(sport, &baud, &parity, &bits); else lpuart_console_get_options(sport, &baud, &parity, &bits); if (lpuart_is_32(sport)) lpuart32_setup_watermark(sport); else lpuart_setup_watermark(sport); return uart_set_options(&sport->port, co, baud, parity, bits, flow); } static struct uart_driver lpuart_reg; static struct console lpuart_console = { .name = DEV_NAME, .write = lpuart_console_write, .device = uart_console_device, .setup = lpuart_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &lpuart_reg, }; static struct console lpuart32_console = { .name = DEV_NAME, .write = lpuart32_console_write, .device = uart_console_device, .setup = lpuart_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &lpuart_reg, }; static void lpuart_early_write(struct console *con, const char *s, unsigned n) { struct earlycon_device *dev = con->data; uart_console_write(&dev->port, s, n, lpuart_console_putchar); } static void lpuart32_early_write(struct console *con, const char *s, unsigned n) { struct earlycon_device *dev = con->data; uart_console_write(&dev->port, s, n, lpuart32_console_putchar); } static int __init lpuart_early_console_setup(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; device->con->write = lpuart_early_write; return 0; } static int __init lpuart32_early_console_setup(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; if (device->port.iotype != UPIO_MEM32) device->port.iotype = UPIO_MEM32BE; device->con->write = lpuart32_early_write; return 0; } static int __init ls1028a_early_console_setup(struct earlycon_device *device, const char *opt) { u32 cr; if (!device->port.membase) return -ENODEV; device->port.iotype = UPIO_MEM32; device->con->write = lpuart32_early_write; /* set the baudrate */ if (device->port.uartclk && device->baud) __lpuart32_serial_setbrg(&device->port, device->baud, false, false); /* enable transmitter */ cr = lpuart32_read(&device->port, UARTCTRL); cr |= UARTCTRL_TE; lpuart32_write(&device->port, cr, UARTCTRL); return 0; } static int __init lpuart32_imx_early_console_setup(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; device->port.iotype = UPIO_MEM32; device->port.membase += IMX_REG_OFF; device->con->write = lpuart32_early_write; return 0; } OF_EARLYCON_DECLARE(lpuart, "fsl,vf610-lpuart", lpuart_early_console_setup); OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1021a-lpuart", lpuart32_early_console_setup); OF_EARLYCON_DECLARE(lpuart32, "fsl,ls1028a-lpuart", ls1028a_early_console_setup); OF_EARLYCON_DECLARE(lpuart32, "fsl,imx7ulp-lpuart", lpuart32_imx_early_console_setup); OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8ulp-lpuart", lpuart32_imx_early_console_setup); OF_EARLYCON_DECLARE(lpuart32, "fsl,imx8qxp-lpuart", lpuart32_imx_early_console_setup); EARLYCON_DECLARE(lpuart, lpuart_early_console_setup); EARLYCON_DECLARE(lpuart32, lpuart32_early_console_setup); #define LPUART_CONSOLE (&lpuart_console) #define LPUART32_CONSOLE (&lpuart32_console) #else #define LPUART_CONSOLE NULL #define LPUART32_CONSOLE NULL #endif static struct uart_driver lpuart_reg = { .owner = THIS_MODULE, .driver_name = DRIVER_NAME, .dev_name = DEV_NAME, .nr = ARRAY_SIZE(lpuart_ports), .cons = LPUART_CONSOLE, }; static int lpuart_probe(struct platform_device *pdev) { const struct of_device_id *of_id = of_match_device(lpuart_dt_ids, &pdev->dev); const struct lpuart_soc_data *sdata = of_id->data; struct device_node *np = pdev->dev.of_node; struct lpuart_port *sport; struct resource *res; irq_handler_t handler; int ret; sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); if (!sport) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); sport->port.membase = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(sport->port.membase)) return PTR_ERR(sport->port.membase); sport->port.membase += sdata->reg_off; sport->port.mapbase = res->start + sdata->reg_off; sport->port.dev = &pdev->dev; sport->port.type = PORT_LPUART; sport->devtype = sdata->devtype; ret = platform_get_irq(pdev, 0); if (ret < 0) return ret; sport->port.irq = ret; sport->port.iotype = sdata->iotype; if (lpuart_is_32(sport)) sport->port.ops = &lpuart32_pops; else sport->port.ops = &lpuart_pops; sport->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_FSL_LPUART_CONSOLE); sport->port.flags = UPF_BOOT_AUTOCONF; if (lpuart_is_32(sport)) sport->port.rs485_config = lpuart32_config_rs485; else sport->port.rs485_config = lpuart_config_rs485; sport->ipg_clk = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(sport->ipg_clk)) { ret = PTR_ERR(sport->ipg_clk); dev_err(&pdev->dev, "failed to get uart ipg clk: %d\n", ret); return ret; } sport->baud_clk = NULL; if (is_imx8qxp_lpuart(sport)) { sport->baud_clk = devm_clk_get(&pdev->dev, "baud"); if (IS_ERR(sport->baud_clk)) { ret = PTR_ERR(sport->baud_clk); dev_err(&pdev->dev, "failed to get uart baud clk: %d\n", ret); return ret; } } ret = of_alias_get_id(np, "serial"); if (ret < 0) { dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret); return ret; } if (ret >= ARRAY_SIZE(lpuart_ports)) { dev_err(&pdev->dev, "serial%d out of range\n", ret); return -EINVAL; } sport->port.line = ret; ret = lpuart_enable_clks(sport); if (ret) return ret; sport->port.uartclk = lpuart_get_baud_clk_rate(sport); lpuart_ports[sport->port.line] = sport; platform_set_drvdata(pdev, &sport->port); if (lpuart_is_32(sport)) { lpuart_reg.cons = LPUART32_CONSOLE; handler = lpuart32_int; } else { lpuart_reg.cons = LPUART_CONSOLE; handler = lpuart_int; } ret = uart_get_rs485_mode(&sport->port); if (ret) goto failed_get_rs485; if (sport->port.rs485.flags & SER_RS485_RX_DURING_TX) dev_err(&pdev->dev, "driver doesn't support RX during TX\n"); if (sport->port.rs485.delay_rts_before_send || sport->port.rs485.delay_rts_after_send) dev_err(&pdev->dev, "driver doesn't support RTS delays\n"); ret = uart_add_one_port(&lpuart_reg, &sport->port); if (ret) goto failed_attach_port; ret = devm_request_irq(&pdev->dev, sport->port.irq, handler, 0, DRIVER_NAME, sport); if (ret) goto failed_irq_request; return 0; failed_irq_request: uart_remove_one_port(&lpuart_reg, &sport->port); failed_get_rs485: failed_attach_port: lpuart_disable_clks(sport); return ret; } static int lpuart_remove(struct platform_device *pdev) { struct lpuart_port *sport = platform_get_drvdata(pdev); uart_remove_one_port(&lpuart_reg, &sport->port); lpuart_disable_clks(sport); if (sport->dma_tx_chan) dma_release_channel(sport->dma_tx_chan); if (sport->dma_rx_chan) dma_release_channel(sport->dma_rx_chan); return 0; } static int __maybe_unused lpuart_suspend(struct device *dev) { struct lpuart_port *sport = dev_get_drvdata(dev); unsigned long temp; bool irq_wake; if (lpuart_is_32(sport)) { /* disable Rx/Tx and interrupts */ temp = lpuart32_read(&sport->port, UARTCTRL); temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE); lpuart32_write(&sport->port, temp, UARTCTRL); } else { /* disable Rx/Tx and interrupts */ temp = readb(sport->port.membase + UARTCR2); temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE); writeb(temp, sport->port.membase + UARTCR2); } uart_suspend_port(&lpuart_reg, &sport->port); /* uart_suspend_port() might set wakeup flag */ irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq)); if (sport->lpuart_dma_rx_use) { /* * EDMA driver during suspend will forcefully release any * non-idle DMA channels. If port wakeup is enabled or if port * is console port or 'no_console_suspend' is set the Rx DMA * cannot resume as expected, hence gracefully release the * Rx DMA path before suspend and start Rx DMA path on resume. */ if (irq_wake) { lpuart_dma_rx_free(&sport->port); } /* Disable Rx DMA to use UART port as wakeup source */ if (lpuart_is_32(sport)) { temp = lpuart32_read(&sport->port, UARTBAUD); lpuart32_write(&sport->port, temp & ~UARTBAUD_RDMAE, UARTBAUD); } else { writeb(readb(sport->port.membase + UARTCR5) & ~UARTCR5_RDMAS, sport->port.membase + UARTCR5); } } if (sport->lpuart_dma_tx_use) { sport->dma_tx_in_progress = false; dmaengine_terminate_all(sport->dma_tx_chan); } if (sport->port.suspended && !irq_wake) lpuart_disable_clks(sport); return 0; } static int __maybe_unused lpuart_resume(struct device *dev) { struct lpuart_port *sport = dev_get_drvdata(dev); bool irq_wake = irqd_is_wakeup_set(irq_get_irq_data(sport->port.irq)); if (sport->port.suspended && !irq_wake) lpuart_enable_clks(sport); if (lpuart_is_32(sport)) lpuart32_setup_watermark_enable(sport); else lpuart_setup_watermark_enable(sport); if (sport->lpuart_dma_rx_use) { if (irq_wake) { if (!lpuart_start_rx_dma(sport)) rx_dma_timer_init(sport); else sport->lpuart_dma_rx_use = false; } } lpuart_tx_dma_startup(sport); if (lpuart_is_32(sport)) lpuart32_configure(sport); uart_resume_port(&lpuart_reg, &sport->port); return 0; } static SIMPLE_DEV_PM_OPS(lpuart_pm_ops, lpuart_suspend, lpuart_resume); static struct platform_driver lpuart_driver = { .probe = lpuart_probe, .remove = lpuart_remove, .driver = { .name = "fsl-lpuart", .of_match_table = lpuart_dt_ids, .pm = &lpuart_pm_ops, }, }; static int __init lpuart_serial_init(void) { int ret = uart_register_driver(&lpuart_reg); if (ret) return ret; ret = platform_driver_register(&lpuart_driver); if (ret) uart_unregister_driver(&lpuart_reg); return ret; } static void __exit lpuart_serial_exit(void) { platform_driver_unregister(&lpuart_driver); uart_unregister_driver(&lpuart_reg); } module_init(lpuart_serial_init); module_exit(lpuart_serial_exit); MODULE_DESCRIPTION("Freescale lpuart serial port driver"); MODULE_LICENSE("GPL v2");