diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/tty/serial/sprd_serial.c | 1297 |
1 files changed, 1297 insertions, 0 deletions
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c new file mode 100644 index 000000000..9c7f71993 --- /dev/null +++ b/drivers/tty/serial/sprd_serial.c @@ -0,0 +1,1297 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2012-2015 Spreadtrum Communications Inc. + */ + +#include <linux/clk.h> +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/dma/sprd-dma.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/serial_core.h> +#include <linux/serial.h> +#include <linux/slab.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> + +/* device name */ +#define UART_NR_MAX 8 +#define SPRD_TTY_NAME "ttyS" +#define SPRD_FIFO_SIZE 128 +#define SPRD_DEF_RATE 26000000 +#define SPRD_BAUD_IO_LIMIT 3000000 +#define SPRD_TIMEOUT 256000 + +/* the offset of serial registers and BITs for them */ +/* data registers */ +#define SPRD_TXD 0x0000 +#define SPRD_RXD 0x0004 + +/* line status register and its BITs */ +#define SPRD_LSR 0x0008 +#define SPRD_LSR_OE BIT(4) +#define SPRD_LSR_FE BIT(3) +#define SPRD_LSR_PE BIT(2) +#define SPRD_LSR_BI BIT(7) +#define SPRD_LSR_TX_OVER BIT(15) + +/* data number in TX and RX fifo */ +#define SPRD_STS1 0x000C +#define SPRD_RX_FIFO_CNT_MASK GENMASK(7, 0) +#define SPRD_TX_FIFO_CNT_MASK GENMASK(15, 8) + +/* interrupt enable register and its BITs */ +#define SPRD_IEN 0x0010 +#define SPRD_IEN_RX_FULL BIT(0) +#define SPRD_IEN_TX_EMPTY BIT(1) +#define SPRD_IEN_BREAK_DETECT BIT(7) +#define SPRD_IEN_TIMEOUT BIT(13) + +/* interrupt clear register */ +#define SPRD_ICLR 0x0014 +#define SPRD_ICLR_TIMEOUT BIT(13) + +/* line control register */ +#define SPRD_LCR 0x0018 +#define SPRD_LCR_STOP_1BIT 0x10 +#define SPRD_LCR_STOP_2BIT 0x30 +#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3)) +#define SPRD_LCR_DATA_LEN5 0x0 +#define SPRD_LCR_DATA_LEN6 0x4 +#define SPRD_LCR_DATA_LEN7 0x8 +#define SPRD_LCR_DATA_LEN8 0xc +#define SPRD_LCR_PARITY (BIT(0) | BIT(1)) +#define SPRD_LCR_PARITY_EN 0x2 +#define SPRD_LCR_EVEN_PAR 0x0 +#define SPRD_LCR_ODD_PAR 0x1 + +/* control register 1 */ +#define SPRD_CTL1 0x001C +#define SPRD_DMA_EN BIT(15) +#define SPRD_LOOPBACK_EN BIT(14) +#define RX_HW_FLOW_CTL_THLD BIT(6) +#define RX_HW_FLOW_CTL_EN BIT(7) +#define TX_HW_FLOW_CTL_EN BIT(8) +#define RX_TOUT_THLD_DEF 0x3E00 +#define RX_HFC_THLD_DEF 0x40 + +/* fifo threshold register */ +#define SPRD_CTL2 0x0020 +#define THLD_TX_EMPTY 0x40 +#define THLD_TX_EMPTY_SHIFT 8 +#define THLD_RX_FULL 0x40 +#define THLD_RX_FULL_MASK GENMASK(6, 0) + +/* config baud rate register */ +#define SPRD_CLKD0 0x0024 +#define SPRD_CLKD0_MASK GENMASK(15, 0) +#define SPRD_CLKD1 0x0028 +#define SPRD_CLKD1_MASK GENMASK(20, 16) +#define SPRD_CLKD1_SHIFT 16 + +/* interrupt mask status register */ +#define SPRD_IMSR 0x002C +#define SPRD_IMSR_RX_FIFO_FULL BIT(0) +#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1) +#define SPRD_IMSR_BREAK_DETECT BIT(7) +#define SPRD_IMSR_TIMEOUT BIT(13) +#define SPRD_DEFAULT_SOURCE_CLK 26000000 + +#define SPRD_RX_DMA_STEP 1 +#define SPRD_RX_FIFO_FULL 1 +#define SPRD_TX_FIFO_FULL 0x20 +#define SPRD_UART_RX_SIZE (UART_XMIT_SIZE / 4) + +struct sprd_uart_dma { + struct dma_chan *chn; + unsigned char *virt; + dma_addr_t phys_addr; + dma_cookie_t cookie; + u32 trans_len; + bool enable; +}; + +struct sprd_uart_port { + struct uart_port port; + char name[16]; + struct clk *clk; + struct sprd_uart_dma tx_dma; + struct sprd_uart_dma rx_dma; + dma_addr_t pos; + unsigned char *rx_buf_tail; +}; + +static struct sprd_uart_port *sprd_port[UART_NR_MAX]; +static int sprd_ports_num; + +static int sprd_start_dma_rx(struct uart_port *port); +static int sprd_tx_dma_config(struct uart_port *port); + +static inline unsigned int serial_in(struct uart_port *port, + unsigned int offset) +{ + return readl_relaxed(port->membase + offset); +} + +static inline void serial_out(struct uart_port *port, unsigned int offset, + int value) +{ + writel_relaxed(value, port->membase + offset); +} + +static unsigned int sprd_tx_empty(struct uart_port *port) +{ + if (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK) + return 0; + else + return TIOCSER_TEMT; +} + +static unsigned int sprd_get_mctrl(struct uart_port *port) +{ + return TIOCM_DSR | TIOCM_CTS; +} + +static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + u32 val = serial_in(port, SPRD_CTL1); + + if (mctrl & TIOCM_LOOP) + val |= SPRD_LOOPBACK_EN; + else + val &= ~SPRD_LOOPBACK_EN; + + serial_out(port, SPRD_CTL1, val); +} + +static void sprd_stop_rx(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + unsigned int ien, iclr; + + if (sp->rx_dma.enable) + dmaengine_terminate_all(sp->rx_dma.chn); + + iclr = serial_in(port, SPRD_ICLR); + ien = serial_in(port, SPRD_IEN); + + ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT); + iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT; + + serial_out(port, SPRD_IEN, ien); + serial_out(port, SPRD_ICLR, iclr); +} + +static void sprd_uart_dma_enable(struct uart_port *port, bool enable) +{ + u32 val = serial_in(port, SPRD_CTL1); + + if (enable) + val |= SPRD_DMA_EN; + else + val &= ~SPRD_DMA_EN; + + serial_out(port, SPRD_CTL1, val); +} + +static void sprd_stop_tx_dma(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + struct circ_buf *xmit = &port->state->xmit; + struct dma_tx_state state; + u32 trans_len; + + dmaengine_pause(sp->tx_dma.chn); + + dmaengine_tx_status(sp->tx_dma.chn, sp->tx_dma.cookie, &state); + if (state.residue) { + trans_len = state.residue - sp->tx_dma.phys_addr; + xmit->tail = (xmit->tail + trans_len) & (UART_XMIT_SIZE - 1); + port->icount.tx += trans_len; + dma_unmap_single(port->dev, sp->tx_dma.phys_addr, + sp->tx_dma.trans_len, DMA_TO_DEVICE); + } + + dmaengine_terminate_all(sp->tx_dma.chn); + sp->tx_dma.trans_len = 0; +} + +static int sprd_tx_buf_remap(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + struct circ_buf *xmit = &port->state->xmit; + + sp->tx_dma.trans_len = + CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + + sp->tx_dma.phys_addr = dma_map_single(port->dev, + (void *)&(xmit->buf[xmit->tail]), + sp->tx_dma.trans_len, + DMA_TO_DEVICE); + return dma_mapping_error(port->dev, sp->tx_dma.phys_addr); +} + +static void sprd_complete_tx_dma(void *data) +{ + struct uart_port *port = (struct uart_port *)data; + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + struct circ_buf *xmit = &port->state->xmit; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + dma_unmap_single(port->dev, sp->tx_dma.phys_addr, + sp->tx_dma.trans_len, DMA_TO_DEVICE); + + xmit->tail = (xmit->tail + sp->tx_dma.trans_len) & (UART_XMIT_SIZE - 1); + port->icount.tx += sp->tx_dma.trans_len; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (uart_circ_empty(xmit) || sprd_tx_buf_remap(port) || + sprd_tx_dma_config(port)) + sp->tx_dma.trans_len = 0; + + spin_unlock_irqrestore(&port->lock, flags); +} + +static int sprd_uart_dma_submit(struct uart_port *port, + struct sprd_uart_dma *ud, u32 trans_len, + enum dma_transfer_direction direction, + dma_async_tx_callback callback) +{ + struct dma_async_tx_descriptor *dma_des; + unsigned long flags; + + flags = SPRD_DMA_FLAGS(SPRD_DMA_CHN_MODE_NONE, + SPRD_DMA_NO_TRG, + SPRD_DMA_FRAG_REQ, + SPRD_DMA_TRANS_INT); + + dma_des = dmaengine_prep_slave_single(ud->chn, ud->phys_addr, trans_len, + direction, flags); + if (!dma_des) + return -ENODEV; + + dma_des->callback = callback; + dma_des->callback_param = port; + + ud->cookie = dmaengine_submit(dma_des); + if (dma_submit_error(ud->cookie)) + return dma_submit_error(ud->cookie); + + dma_async_issue_pending(ud->chn); + + return 0; +} + +static int sprd_tx_dma_config(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + u32 burst = sp->tx_dma.trans_len > SPRD_TX_FIFO_FULL ? + SPRD_TX_FIFO_FULL : sp->tx_dma.trans_len; + int ret; + struct dma_slave_config cfg = { + .dst_addr = port->mapbase + SPRD_TXD, + .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, + .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, + .src_maxburst = burst, + }; + + ret = dmaengine_slave_config(sp->tx_dma.chn, &cfg); + if (ret < 0) + return ret; + + return sprd_uart_dma_submit(port, &sp->tx_dma, sp->tx_dma.trans_len, + DMA_MEM_TO_DEV, sprd_complete_tx_dma); +} + +static void sprd_start_tx_dma(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + struct circ_buf *xmit = &port->state->xmit; + + if (port->x_char) { + serial_out(port, SPRD_TXD, port->x_char); + port->icount.tx++; + port->x_char = 0; + return; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + sprd_stop_tx_dma(port); + return; + } + + if (sp->tx_dma.trans_len) + return; + + if (sprd_tx_buf_remap(port) || sprd_tx_dma_config(port)) + sp->tx_dma.trans_len = 0; +} + +static void sprd_rx_full_thld(struct uart_port *port, u32 thld) +{ + u32 val = serial_in(port, SPRD_CTL2); + + val &= ~THLD_RX_FULL_MASK; + val |= thld & THLD_RX_FULL_MASK; + serial_out(port, SPRD_CTL2, val); +} + +static int sprd_rx_alloc_buf(struct sprd_uart_port *sp) +{ + sp->rx_dma.virt = dma_alloc_coherent(sp->port.dev, SPRD_UART_RX_SIZE, + &sp->rx_dma.phys_addr, GFP_KERNEL); + if (!sp->rx_dma.virt) + return -ENOMEM; + + return 0; +} + +static void sprd_rx_free_buf(struct sprd_uart_port *sp) +{ + if (sp->rx_dma.virt) + dma_free_coherent(sp->port.dev, SPRD_UART_RX_SIZE, + sp->rx_dma.virt, sp->rx_dma.phys_addr); + sp->rx_dma.virt = NULL; +} + +static int sprd_rx_dma_config(struct uart_port *port, u32 burst) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + struct dma_slave_config cfg = { + .src_addr = port->mapbase + SPRD_RXD, + .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, + .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, + .src_maxburst = burst, + }; + + return dmaengine_slave_config(sp->rx_dma.chn, &cfg); +} + +static void sprd_uart_dma_rx(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + struct tty_port *tty = &port->state->port; + + port->icount.rx += sp->rx_dma.trans_len; + tty_insert_flip_string(tty, sp->rx_buf_tail, sp->rx_dma.trans_len); + tty_flip_buffer_push(tty); +} + +static void sprd_uart_dma_irq(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + struct dma_tx_state state; + enum dma_status status; + + status = dmaengine_tx_status(sp->rx_dma.chn, + sp->rx_dma.cookie, &state); + if (status == DMA_ERROR) + sprd_stop_rx(port); + + if (!state.residue && sp->pos == sp->rx_dma.phys_addr) + return; + + if (!state.residue) { + sp->rx_dma.trans_len = SPRD_UART_RX_SIZE + + sp->rx_dma.phys_addr - sp->pos; + sp->pos = sp->rx_dma.phys_addr; + } else { + sp->rx_dma.trans_len = state.residue - sp->pos; + sp->pos = state.residue; + } + + sprd_uart_dma_rx(port); + sp->rx_buf_tail += sp->rx_dma.trans_len; +} + +static void sprd_complete_rx_dma(void *data) +{ + struct uart_port *port = (struct uart_port *)data; + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + struct dma_tx_state state; + enum dma_status status; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + + status = dmaengine_tx_status(sp->rx_dma.chn, + sp->rx_dma.cookie, &state); + if (status != DMA_COMPLETE) { + sprd_stop_rx(port); + spin_unlock_irqrestore(&port->lock, flags); + return; + } + + if (sp->pos != sp->rx_dma.phys_addr) { + sp->rx_dma.trans_len = SPRD_UART_RX_SIZE + + sp->rx_dma.phys_addr - sp->pos; + sprd_uart_dma_rx(port); + sp->rx_buf_tail += sp->rx_dma.trans_len; + } + + if (sprd_start_dma_rx(port)) + sprd_stop_rx(port); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static int sprd_start_dma_rx(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + int ret; + + if (!sp->rx_dma.enable) + return 0; + + sp->pos = sp->rx_dma.phys_addr; + sp->rx_buf_tail = sp->rx_dma.virt; + sprd_rx_full_thld(port, SPRD_RX_FIFO_FULL); + ret = sprd_rx_dma_config(port, SPRD_RX_DMA_STEP); + if (ret) + return ret; + + return sprd_uart_dma_submit(port, &sp->rx_dma, SPRD_UART_RX_SIZE, + DMA_DEV_TO_MEM, sprd_complete_rx_dma); +} + +static void sprd_release_dma(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + + sprd_uart_dma_enable(port, false); + + if (sp->rx_dma.enable) + dma_release_channel(sp->rx_dma.chn); + + if (sp->tx_dma.enable) + dma_release_channel(sp->tx_dma.chn); + + sp->tx_dma.enable = false; + sp->rx_dma.enable = false; +} + +static void sprd_request_dma(struct uart_port *port) +{ + struct sprd_uart_port *sp = + container_of(port, struct sprd_uart_port, port); + + sp->tx_dma.enable = true; + sp->rx_dma.enable = true; + + sp->tx_dma.chn = dma_request_chan(port->dev, "tx"); + if (IS_ERR(sp->tx_dma.chn)) { + dev_err(port->dev, "request TX DMA channel failed, ret = %ld\n", + PTR_ERR(sp->tx_dma.chn)); + sp->tx_dma.enable = false; + } + + sp->rx_dma.chn = dma_request_chan(port->dev, "rx"); + if (IS_ERR(sp->rx_dma.chn)) { + dev_err(port->dev, "request RX DMA channel failed, ret = %ld\n", + PTR_ERR(sp->rx_dma.chn)); + sp->rx_dma.enable = false; + } +} + +static void sprd_stop_tx(struct uart_port *port) +{ + struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, + port); + unsigned int ien, iclr; + + if (sp->tx_dma.enable) { + sprd_stop_tx_dma(port); + return; + } + + iclr = serial_in(port, SPRD_ICLR); + ien = serial_in(port, SPRD_IEN); + + iclr |= SPRD_IEN_TX_EMPTY; + ien &= ~SPRD_IEN_TX_EMPTY; + + serial_out(port, SPRD_IEN, ien); + serial_out(port, SPRD_ICLR, iclr); +} + +static void sprd_start_tx(struct uart_port *port) +{ + struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, + port); + unsigned int ien; + + if (sp->tx_dma.enable) { + sprd_start_tx_dma(port); + return; + } + + ien = serial_in(port, SPRD_IEN); + if (!(ien & SPRD_IEN_TX_EMPTY)) { + ien |= SPRD_IEN_TX_EMPTY; + serial_out(port, SPRD_IEN, ien); + } +} + +/* The Sprd serial does not support this function. */ +static void sprd_break_ctl(struct uart_port *port, int break_state) +{ + /* nothing to do */ +} + +static int handle_lsr_errors(struct uart_port *port, + unsigned int *flag, + unsigned int *lsr) +{ + int ret = 0; + + /* statistics */ + if (*lsr & SPRD_LSR_BI) { + *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE); + port->icount.brk++; + ret = uart_handle_break(port); + if (ret) + return ret; + } else if (*lsr & SPRD_LSR_PE) + port->icount.parity++; + else if (*lsr & SPRD_LSR_FE) + port->icount.frame++; + if (*lsr & SPRD_LSR_OE) + port->icount.overrun++; + + /* mask off conditions which should be ignored */ + *lsr &= port->read_status_mask; + if (*lsr & SPRD_LSR_BI) + *flag = TTY_BREAK; + else if (*lsr & SPRD_LSR_PE) + *flag = TTY_PARITY; + else if (*lsr & SPRD_LSR_FE) + *flag = TTY_FRAME; + + return ret; +} + +static inline void sprd_rx(struct uart_port *port) +{ + struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, + port); + struct tty_port *tty = &port->state->port; + unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT; + + if (sp->rx_dma.enable) { + sprd_uart_dma_irq(port); + return; + } + + while ((serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK) && + max_count--) { + lsr = serial_in(port, SPRD_LSR); + ch = serial_in(port, SPRD_RXD); + flag = TTY_NORMAL; + port->icount.rx++; + + if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE | + SPRD_LSR_FE | SPRD_LSR_OE)) + if (handle_lsr_errors(port, &flag, &lsr)) + continue; + if (uart_handle_sysrq_char(port, ch)) + continue; + + uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag); + } + + tty_flip_buffer_push(tty); +} + +static inline void sprd_tx(struct uart_port *port) +{ + struct circ_buf *xmit = &port->state->xmit; + int count; + + if (port->x_char) { + serial_out(port, SPRD_TXD, port->x_char); + port->icount.tx++; + port->x_char = 0; + return; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + sprd_stop_tx(port); + return; + } + + count = THLD_TX_EMPTY; + do { + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + if (uart_circ_empty(xmit)) + break; + } while (--count > 0); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (uart_circ_empty(xmit)) + sprd_stop_tx(port); +} + +/* this handles the interrupt from one port */ +static irqreturn_t sprd_handle_irq(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + unsigned int ims; + + spin_lock(&port->lock); + + ims = serial_in(port, SPRD_IMSR); + + if (!ims) { + spin_unlock(&port->lock); + return IRQ_NONE; + } + + if (ims & SPRD_IMSR_TIMEOUT) + serial_out(port, SPRD_ICLR, SPRD_ICLR_TIMEOUT); + + if (ims & SPRD_IMSR_BREAK_DETECT) + serial_out(port, SPRD_ICLR, SPRD_IMSR_BREAK_DETECT); + + if (ims & (SPRD_IMSR_RX_FIFO_FULL | SPRD_IMSR_BREAK_DETECT | + SPRD_IMSR_TIMEOUT)) + sprd_rx(port); + + if (ims & SPRD_IMSR_TX_FIFO_EMPTY) + sprd_tx(port); + + spin_unlock(&port->lock); + + return IRQ_HANDLED; +} + +static void sprd_uart_dma_startup(struct uart_port *port, + struct sprd_uart_port *sp) +{ + int ret; + + sprd_request_dma(port); + if (!(sp->rx_dma.enable || sp->tx_dma.enable)) + return; + + ret = sprd_start_dma_rx(port); + if (ret) { + sp->rx_dma.enable = false; + dma_release_channel(sp->rx_dma.chn); + dev_warn(port->dev, "fail to start RX dma mode\n"); + } + + sprd_uart_dma_enable(port, true); +} + +static int sprd_startup(struct uart_port *port) +{ + int ret = 0; + unsigned int ien, fc; + unsigned int timeout; + struct sprd_uart_port *sp; + unsigned long flags; + + serial_out(port, SPRD_CTL2, + THLD_TX_EMPTY << THLD_TX_EMPTY_SHIFT | THLD_RX_FULL); + + /* clear rx fifo */ + timeout = SPRD_TIMEOUT; + while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK) + serial_in(port, SPRD_RXD); + + /* clear tx fifo */ + timeout = SPRD_TIMEOUT; + while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK) + cpu_relax(); + + /* clear interrupt */ + serial_out(port, SPRD_IEN, 0); + serial_out(port, SPRD_ICLR, ~0); + + /* allocate irq */ + sp = container_of(port, struct sprd_uart_port, port); + snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line); + + sprd_uart_dma_startup(port, sp); + + ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq, + IRQF_SHARED, sp->name, port); + if (ret) { + dev_err(port->dev, "fail to request serial irq %d, ret=%d\n", + port->irq, ret); + return ret; + } + fc = serial_in(port, SPRD_CTL1); + fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF; + serial_out(port, SPRD_CTL1, fc); + + /* enable interrupt */ + spin_lock_irqsave(&port->lock, flags); + ien = serial_in(port, SPRD_IEN); + ien |= SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT; + if (!sp->rx_dma.enable) + ien |= SPRD_IEN_RX_FULL; + serial_out(port, SPRD_IEN, ien); + spin_unlock_irqrestore(&port->lock, flags); + + return 0; +} + +static void sprd_shutdown(struct uart_port *port) +{ + sprd_release_dma(port); + serial_out(port, SPRD_IEN, 0); + serial_out(port, SPRD_ICLR, ~0); + devm_free_irq(port->dev, port->irq, port); +} + +static void sprd_set_termios(struct uart_port *port, struct ktermios *termios, + const struct ktermios *old) +{ + unsigned int baud, quot; + unsigned int lcr = 0, fc; + unsigned long flags; + + /* ask the core to calculate the divisor for us */ + baud = uart_get_baud_rate(port, termios, old, 0, SPRD_BAUD_IO_LIMIT); + + quot = port->uartclk / baud; + + /* set data length */ + switch (termios->c_cflag & CSIZE) { + case CS5: + lcr |= SPRD_LCR_DATA_LEN5; + break; + case CS6: + lcr |= SPRD_LCR_DATA_LEN6; + break; + case CS7: + lcr |= SPRD_LCR_DATA_LEN7; + break; + case CS8: + default: + lcr |= SPRD_LCR_DATA_LEN8; + break; + } + + /* calculate stop bits */ + lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT); + if (termios->c_cflag & CSTOPB) + lcr |= SPRD_LCR_STOP_2BIT; + else + lcr |= SPRD_LCR_STOP_1BIT; + + /* calculate parity */ + lcr &= ~SPRD_LCR_PARITY; + termios->c_cflag &= ~CMSPAR; /* no support mark/space */ + if (termios->c_cflag & PARENB) { + lcr |= SPRD_LCR_PARITY_EN; + if (termios->c_cflag & PARODD) + lcr |= SPRD_LCR_ODD_PAR; + else + lcr |= SPRD_LCR_EVEN_PAR; + } + + spin_lock_irqsave(&port->lock, flags); + + /* update the per-port timeout */ + uart_update_timeout(port, termios->c_cflag, baud); + + port->read_status_mask = SPRD_LSR_OE; + if (termios->c_iflag & INPCK) + port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE; + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + port->read_status_mask |= SPRD_LSR_BI; + + /* characters to ignore */ + port->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE; + if (termios->c_iflag & IGNBRK) { + port->ignore_status_mask |= SPRD_LSR_BI; + /* + * If we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= SPRD_LSR_OE; + } + + /* flow control */ + fc = serial_in(port, SPRD_CTL1); + fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN); + if (termios->c_cflag & CRTSCTS) { + fc |= RX_HW_FLOW_CTL_THLD; + fc |= RX_HW_FLOW_CTL_EN; + fc |= TX_HW_FLOW_CTL_EN; + } + + /* clock divider bit0~bit15 */ + serial_out(port, SPRD_CLKD0, quot & SPRD_CLKD0_MASK); + + /* clock divider bit16~bit20 */ + serial_out(port, SPRD_CLKD1, + (quot & SPRD_CLKD1_MASK) >> SPRD_CLKD1_SHIFT); + serial_out(port, SPRD_LCR, lcr); + fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF; + serial_out(port, SPRD_CTL1, fc); + + spin_unlock_irqrestore(&port->lock, flags); + + /* Don't rewrite B0 */ + if (tty_termios_baud_rate(termios)) + tty_termios_encode_baud_rate(termios, baud, baud); +} + +static const char *sprd_type(struct uart_port *port) +{ + return "SPX"; +} + +static void sprd_release_port(struct uart_port *port) +{ + /* nothing to do */ +} + +static int sprd_request_port(struct uart_port *port) +{ + return 0; +} + +static void sprd_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) + port->type = PORT_SPRD; +} + +static int sprd_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + if (ser->type != PORT_SPRD) + return -EINVAL; + if (port->irq != ser->irq) + return -EINVAL; + if (port->iotype != ser->io_type) + return -EINVAL; + return 0; +} + +static void sprd_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct sprd_uart_port *sup = + container_of(port, struct sprd_uart_port, port); + + switch (state) { + case UART_PM_STATE_ON: + clk_prepare_enable(sup->clk); + break; + case UART_PM_STATE_OFF: + clk_disable_unprepare(sup->clk); + break; + } +} + +#ifdef CONFIG_CONSOLE_POLL +static int sprd_poll_init(struct uart_port *port) +{ + if (port->state->pm_state != UART_PM_STATE_ON) { + sprd_pm(port, UART_PM_STATE_ON, 0); + port->state->pm_state = UART_PM_STATE_ON; + } + + return 0; +} + +static int sprd_poll_get_char(struct uart_port *port) +{ + while (!(serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK)) + cpu_relax(); + + return serial_in(port, SPRD_RXD); +} + +static void sprd_poll_put_char(struct uart_port *port, unsigned char ch) +{ + while (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK) + cpu_relax(); + + serial_out(port, SPRD_TXD, ch); +} +#endif + +static const struct uart_ops serial_sprd_ops = { + .tx_empty = sprd_tx_empty, + .get_mctrl = sprd_get_mctrl, + .set_mctrl = sprd_set_mctrl, + .stop_tx = sprd_stop_tx, + .start_tx = sprd_start_tx, + .stop_rx = sprd_stop_rx, + .break_ctl = sprd_break_ctl, + .startup = sprd_startup, + .shutdown = sprd_shutdown, + .set_termios = sprd_set_termios, + .type = sprd_type, + .release_port = sprd_release_port, + .request_port = sprd_request_port, + .config_port = sprd_config_port, + .verify_port = sprd_verify_port, + .pm = sprd_pm, +#ifdef CONFIG_CONSOLE_POLL + .poll_init = sprd_poll_init, + .poll_get_char = sprd_poll_get_char, + .poll_put_char = sprd_poll_put_char, +#endif +}; + +#ifdef CONFIG_SERIAL_SPRD_CONSOLE +static void wait_for_xmitr(struct uart_port *port) +{ + unsigned int status, tmout = 10000; + + /* wait up to 10ms for the character(s) to be sent */ + do { + status = serial_in(port, SPRD_STS1); + if (--tmout == 0) + break; + udelay(1); + } while (status & SPRD_TX_FIFO_CNT_MASK); +} + +static void sprd_console_putchar(struct uart_port *port, unsigned char ch) +{ + wait_for_xmitr(port); + serial_out(port, SPRD_TXD, ch); +} + +static void sprd_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_port *port = &sprd_port[co->index]->port; + int locked = 1; + unsigned long flags; + + if (port->sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock_irqsave(&port->lock, flags); + else + spin_lock_irqsave(&port->lock, flags); + + uart_console_write(port, s, count, sprd_console_putchar); + + /* wait for transmitter to become empty */ + wait_for_xmitr(port); + + if (locked) + spin_unlock_irqrestore(&port->lock, flags); +} + +static int sprd_console_setup(struct console *co, char *options) +{ + struct sprd_uart_port *sprd_uart_port; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index >= UART_NR_MAX || co->index < 0) + co->index = 0; + + sprd_uart_port = sprd_port[co->index]; + if (!sprd_uart_port || !sprd_uart_port->port.membase) { + pr_info("serial port %d not yet initialized\n", co->index); + return -ENODEV; + } + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(&sprd_uart_port->port, co, baud, + parity, bits, flow); +} + +static struct uart_driver sprd_uart_driver; +static struct console sprd_console = { + .name = SPRD_TTY_NAME, + .write = sprd_console_write, + .device = uart_console_device, + .setup = sprd_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &sprd_uart_driver, +}; + +static int __init sprd_serial_console_init(void) +{ + register_console(&sprd_console); + return 0; +} +console_initcall(sprd_serial_console_init); + +#define SPRD_CONSOLE (&sprd_console) + +/* Support for earlycon */ +static void sprd_putc(struct uart_port *port, unsigned char c) +{ + unsigned int timeout = SPRD_TIMEOUT; + + while (timeout-- && + !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER)) + cpu_relax(); + + writeb(c, port->membase + SPRD_TXD); +} + +static void sprd_early_write(struct console *con, const char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + + uart_console_write(&dev->port, s, n, sprd_putc); +} + +static int __init sprd_early_console_setup(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = sprd_early_write; + return 0; +} +OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart", + sprd_early_console_setup); + +#else /* !CONFIG_SERIAL_SPRD_CONSOLE */ +#define SPRD_CONSOLE NULL +#endif + +static struct uart_driver sprd_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "sprd_serial", + .dev_name = SPRD_TTY_NAME, + .major = 0, + .minor = 0, + .nr = UART_NR_MAX, + .cons = SPRD_CONSOLE, +}; + +static int sprd_remove(struct platform_device *dev) +{ + struct sprd_uart_port *sup = platform_get_drvdata(dev); + + if (sup) { + uart_remove_one_port(&sprd_uart_driver, &sup->port); + sprd_port[sup->port.line] = NULL; + sprd_rx_free_buf(sup); + sprd_ports_num--; + } + + if (!sprd_ports_num) + uart_unregister_driver(&sprd_uart_driver); + + return 0; +} + +static bool sprd_uart_is_console(struct uart_port *uport) +{ + struct console *cons = sprd_uart_driver.cons; + + if ((cons && cons->index >= 0 && cons->index == uport->line) || + of_console_check(uport->dev->of_node, SPRD_TTY_NAME, uport->line)) + return true; + + return false; +} + +static int sprd_clk_init(struct uart_port *uport) +{ + struct clk *clk_uart, *clk_parent; + struct sprd_uart_port *u = container_of(uport, struct sprd_uart_port, port); + + clk_uart = devm_clk_get(uport->dev, "uart"); + if (IS_ERR(clk_uart)) { + dev_warn(uport->dev, "uart%d can't get uart clock\n", + uport->line); + clk_uart = NULL; + } + + clk_parent = devm_clk_get(uport->dev, "source"); + if (IS_ERR(clk_parent)) { + dev_warn(uport->dev, "uart%d can't get source clock\n", + uport->line); + clk_parent = NULL; + } + + if (!clk_uart || clk_set_parent(clk_uart, clk_parent)) + uport->uartclk = SPRD_DEFAULT_SOURCE_CLK; + else + uport->uartclk = clk_get_rate(clk_uart); + + u->clk = devm_clk_get(uport->dev, "enable"); + if (IS_ERR(u->clk)) { + if (PTR_ERR(u->clk) == -EPROBE_DEFER) + return -EPROBE_DEFER; + + dev_warn(uport->dev, "uart%d can't get enable clock\n", + uport->line); + + /* To keep console alive even if the error occurred */ + if (!sprd_uart_is_console(uport)) + return PTR_ERR(u->clk); + + u->clk = NULL; + } + + return 0; +} + +static int sprd_probe(struct platform_device *pdev) +{ + struct resource *res; + struct uart_port *up; + struct sprd_uart_port *sport; + int irq; + int index; + int ret; + + index = of_alias_get_id(pdev->dev.of_node, "serial"); + if (index < 0 || index >= UART_NR_MAX) { + dev_err(&pdev->dev, "got a wrong serial alias id %d\n", index); + return -EINVAL; + } + + sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); + if (!sport) + return -ENOMEM; + + up = &sport->port; + up->dev = &pdev->dev; + up->line = index; + up->type = PORT_SPRD; + up->iotype = UPIO_MEM; + up->uartclk = SPRD_DEF_RATE; + up->fifosize = SPRD_FIFO_SIZE; + up->ops = &serial_sprd_ops; + up->flags = UPF_BOOT_AUTOCONF; + up->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SPRD_CONSOLE); + + ret = sprd_clk_init(up); + if (ret) + return ret; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + up->membase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(up->membase)) + return PTR_ERR(up->membase); + + up->mapbase = res->start; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + up->irq = irq; + + /* + * Allocate one dma buffer to prepare for receive transfer, in case + * memory allocation failure at runtime. + */ + ret = sprd_rx_alloc_buf(sport); + if (ret) + return ret; + + if (!sprd_ports_num) { + ret = uart_register_driver(&sprd_uart_driver); + if (ret < 0) { + pr_err("Failed to register SPRD-UART driver\n"); + goto free_rx_buf; + } + } + + sprd_ports_num++; + sprd_port[index] = sport; + + ret = uart_add_one_port(&sprd_uart_driver, up); + if (ret) + goto clean_port; + + platform_set_drvdata(pdev, up); + + return 0; + +clean_port: + sprd_port[index] = NULL; + if (--sprd_ports_num == 0) + uart_unregister_driver(&sprd_uart_driver); +free_rx_buf: + sprd_rx_free_buf(sport); + return ret; +} + +#ifdef CONFIG_PM_SLEEP +static int sprd_suspend(struct device *dev) +{ + struct sprd_uart_port *sup = dev_get_drvdata(dev); + + uart_suspend_port(&sprd_uart_driver, &sup->port); + + return 0; +} + +static int sprd_resume(struct device *dev) +{ + struct sprd_uart_port *sup = dev_get_drvdata(dev); + + uart_resume_port(&sprd_uart_driver, &sup->port); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume); + +static const struct of_device_id serial_ids[] = { + {.compatible = "sprd,sc9836-uart",}, + {} +}; +MODULE_DEVICE_TABLE(of, serial_ids); + +static struct platform_driver sprd_platform_driver = { + .probe = sprd_probe, + .remove = sprd_remove, + .driver = { + .name = "sprd_serial", + .of_match_table = of_match_ptr(serial_ids), + .pm = &sprd_pm_ops, + }, +}; + +module_platform_driver(sprd_platform_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Spreadtrum SoC serial driver series"); |