From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/tty/serial/8250/8250_mtk.c | 677 +++++++++++++++++++++++++++++++++++++ 1 file changed, 677 insertions(+) create mode 100644 drivers/tty/serial/8250/8250_mtk.c (limited to 'drivers/tty/serial/8250/8250_mtk.c') diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c new file mode 100644 index 0000000000..74da5676ce --- /dev/null +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -0,0 +1,677 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Mediatek 8250 driver. + * + * Copyright (c) 2014 MundoReader S.L. + * Author: Matthias Brugger + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "8250.h" + +#define MTK_UART_HIGHS 0x09 /* Highspeed register */ +#define MTK_UART_SAMPLE_COUNT 0x0a /* Sample count register */ +#define MTK_UART_SAMPLE_POINT 0x0b /* Sample point register */ +#define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */ +#define MTK_UART_ESCAPE_DAT 0x10 /* Escape Character register */ +#define MTK_UART_ESCAPE_EN 0x11 /* Escape Enable register */ +#define MTK_UART_DMA_EN 0x13 /* DMA Enable register */ +#define MTK_UART_RXTRI_AD 0x14 /* RX Trigger address */ +#define MTK_UART_FRACDIV_L 0x15 /* Fractional divider LSB address */ +#define MTK_UART_FRACDIV_M 0x16 /* Fractional divider MSB address */ +#define MTK_UART_DEBUG0 0x18 +#define MTK_UART_IER_XOFFI 0x20 /* Enable XOFF character interrupt */ +#define MTK_UART_IER_RTSI 0x40 /* Enable RTS Modem status interrupt */ +#define MTK_UART_IER_CTSI 0x80 /* Enable CTS Modem status interrupt */ + +#define MTK_UART_EFR 38 /* I/O: Extended Features Register */ +#define MTK_UART_EFR_EN 0x10 /* Enable enhancement feature */ +#define MTK_UART_EFR_RTS 0x40 /* Enable hardware rx flow control */ +#define MTK_UART_EFR_CTS 0x80 /* Enable hardware tx flow control */ +#define MTK_UART_EFR_NO_SW_FC 0x0 /* no sw flow control */ +#define MTK_UART_EFR_XON1_XOFF1 0xa /* XON1/XOFF1 as sw flow control */ +#define MTK_UART_EFR_XON2_XOFF2 0x5 /* XON2/XOFF2 as sw flow control */ +#define MTK_UART_EFR_SW_FC_MASK 0xf /* Enable CTS Modem status interrupt */ +#define MTK_UART_EFR_HW_FC (MTK_UART_EFR_RTS | MTK_UART_EFR_CTS) +#define MTK_UART_DMA_EN_TX 0x2 +#define MTK_UART_DMA_EN_RX 0x5 + +#define MTK_UART_ESCAPE_CHAR 0x77 /* Escape char added under sw fc */ +#define MTK_UART_RX_SIZE 0x8000 +#define MTK_UART_TX_TRIGGER 1 +#define MTK_UART_RX_TRIGGER MTK_UART_RX_SIZE + +#define MTK_UART_XON1 40 /* I/O: Xon character 1 */ +#define MTK_UART_XOFF1 42 /* I/O: Xoff character 1 */ + +#ifdef CONFIG_SERIAL_8250_DMA +enum dma_rx_status { + DMA_RX_START = 0, + DMA_RX_RUNNING = 1, + DMA_RX_SHUTDOWN = 2, +}; +#endif + +struct mtk8250_data { + int line; + unsigned int rx_pos; + unsigned int clk_count; + struct clk *uart_clk; + struct clk *bus_clk; + struct uart_8250_dma *dma; +#ifdef CONFIG_SERIAL_8250_DMA + enum dma_rx_status rx_status; +#endif + int rx_wakeup_irq; +}; + +/* flow control mode */ +enum { + MTK_UART_FC_NONE, + MTK_UART_FC_SW, + MTK_UART_FC_HW, +}; + +#ifdef CONFIG_SERIAL_8250_DMA +static void mtk8250_rx_dma(struct uart_8250_port *up); + +static void mtk8250_dma_rx_complete(void *param) +{ + struct uart_8250_port *up = param; + struct uart_8250_dma *dma = up->dma; + struct mtk8250_data *data = up->port.private_data; + struct tty_port *tty_port = &up->port.state->port; + struct dma_tx_state state; + int copied, total, cnt; + unsigned char *ptr; + unsigned long flags; + + if (data->rx_status == DMA_RX_SHUTDOWN) + return; + + spin_lock_irqsave(&up->port.lock, flags); + + dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); + total = dma->rx_size - state.residue; + cnt = total; + + if ((data->rx_pos + cnt) > dma->rx_size) + cnt = dma->rx_size - data->rx_pos; + + ptr = (unsigned char *)(data->rx_pos + dma->rx_buf); + copied = tty_insert_flip_string(tty_port, ptr, cnt); + data->rx_pos += cnt; + + if (total > cnt) { + ptr = (unsigned char *)(dma->rx_buf); + cnt = total - cnt; + copied += tty_insert_flip_string(tty_port, ptr, cnt); + data->rx_pos = cnt; + } + + up->port.icount.rx += copied; + + tty_flip_buffer_push(tty_port); + + mtk8250_rx_dma(up); + + spin_unlock_irqrestore(&up->port.lock, flags); +} + +static void mtk8250_rx_dma(struct uart_8250_port *up) +{ + struct uart_8250_dma *dma = up->dma; + struct dma_async_tx_descriptor *desc; + + desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr, + dma->rx_size, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + pr_err("failed to prepare rx slave single\n"); + return; + } + + desc->callback = mtk8250_dma_rx_complete; + desc->callback_param = up; + + dma->rx_cookie = dmaengine_submit(desc); + + dma_async_issue_pending(dma->rxchan); +} + +static void mtk8250_dma_enable(struct uart_8250_port *up) +{ + struct uart_8250_dma *dma = up->dma; + struct mtk8250_data *data = up->port.private_data; + int lcr = serial_in(up, UART_LCR); + + if (data->rx_status != DMA_RX_START) + return; + + dma->rxconf.src_port_window_size = dma->rx_size; + dma->rxconf.src_addr = dma->rx_addr; + + dma->txconf.dst_port_window_size = UART_XMIT_SIZE; + dma->txconf.dst_addr = dma->tx_addr; + + serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | + UART_FCR_CLEAR_XMIT); + serial_out(up, MTK_UART_DMA_EN, + MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX); + + serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); + serial_out(up, MTK_UART_EFR, UART_EFR_ECB); + serial_out(up, UART_LCR, lcr); + + if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0) + pr_err("failed to configure rx dma channel\n"); + if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0) + pr_err("failed to configure tx dma channel\n"); + + data->rx_status = DMA_RX_RUNNING; + data->rx_pos = 0; + mtk8250_rx_dma(up); +} +#endif + +static int mtk8250_startup(struct uart_port *port) +{ +#ifdef CONFIG_SERIAL_8250_DMA + struct uart_8250_port *up = up_to_u8250p(port); + struct mtk8250_data *data = port->private_data; + + /* disable DMA for console */ + if (uart_console(port)) + up->dma = NULL; + + if (up->dma) { + data->rx_status = DMA_RX_START; + uart_circ_clear(&port->state->xmit); + } +#endif + memset(&port->icount, 0, sizeof(port->icount)); + + return serial8250_do_startup(port); +} + +static void mtk8250_shutdown(struct uart_port *port) +{ +#ifdef CONFIG_SERIAL_8250_DMA + struct uart_8250_port *up = up_to_u8250p(port); + struct mtk8250_data *data = port->private_data; + + if (up->dma) + data->rx_status = DMA_RX_SHUTDOWN; +#endif + + return serial8250_do_shutdown(port); +} + +static void mtk8250_disable_intrs(struct uart_8250_port *up, int mask) +{ + /* Port locked to synchronize UART_IER access against the console. */ + lockdep_assert_held_once(&up->port.lock); + + serial_out(up, UART_IER, serial_in(up, UART_IER) & (~mask)); +} + +static void mtk8250_enable_intrs(struct uart_8250_port *up, int mask) +{ + /* Port locked to synchronize UART_IER access against the console. */ + lockdep_assert_held_once(&up->port.lock); + + serial_out(up, UART_IER, serial_in(up, UART_IER) | mask); +} + +static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode) +{ + struct uart_port *port = &up->port; + int lcr = serial_in(up, UART_LCR); + + /* Port locked to synchronize UART_IER access against the console. */ + lockdep_assert_held_once(&port->lock); + + serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); + serial_out(up, MTK_UART_EFR, UART_EFR_ECB); + serial_out(up, UART_LCR, lcr); + lcr = serial_in(up, UART_LCR); + + switch (mode) { + case MTK_UART_FC_NONE: + serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR); + serial_out(up, MTK_UART_ESCAPE_EN, 0x00); + serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); + serial_out(up, MTK_UART_EFR, serial_in(up, MTK_UART_EFR) & + (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK))); + serial_out(up, UART_LCR, lcr); + mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI | + MTK_UART_IER_RTSI | MTK_UART_IER_CTSI); + break; + + case MTK_UART_FC_HW: + serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR); + serial_out(up, MTK_UART_ESCAPE_EN, 0x00); + serial_out(up, UART_MCR, UART_MCR_RTS); + serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); + + /*enable hw flow control*/ + serial_out(up, MTK_UART_EFR, MTK_UART_EFR_HW_FC | + (serial_in(up, MTK_UART_EFR) & + (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)))); + + serial_out(up, UART_LCR, lcr); + mtk8250_disable_intrs(up, MTK_UART_IER_XOFFI); + mtk8250_enable_intrs(up, MTK_UART_IER_CTSI | MTK_UART_IER_RTSI); + break; + + case MTK_UART_FC_SW: /*MTK software flow control */ + serial_out(up, MTK_UART_ESCAPE_DAT, MTK_UART_ESCAPE_CHAR); + serial_out(up, MTK_UART_ESCAPE_EN, 0x01); + serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); + + /*enable sw flow control */ + serial_out(up, MTK_UART_EFR, MTK_UART_EFR_XON1_XOFF1 | + (serial_in(up, MTK_UART_EFR) & + (~(MTK_UART_EFR_HW_FC | MTK_UART_EFR_SW_FC_MASK)))); + + serial_out(up, MTK_UART_XON1, START_CHAR(port->state->port.tty)); + serial_out(up, MTK_UART_XOFF1, STOP_CHAR(port->state->port.tty)); + serial_out(up, UART_LCR, lcr); + mtk8250_disable_intrs(up, MTK_UART_IER_CTSI|MTK_UART_IER_RTSI); + mtk8250_enable_intrs(up, MTK_UART_IER_XOFFI); + break; + default: + break; + } +} + +static void +mtk8250_set_termios(struct uart_port *port, struct ktermios *termios, + const struct ktermios *old) +{ + static const unsigned short fraction_L_mapping[] = { + 0, 1, 0x5, 0x15, 0x55, 0x57, 0x57, 0x77, 0x7F, 0xFF, 0xFF + }; + static const unsigned short fraction_M_mapping[] = { + 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3 + }; + struct uart_8250_port *up = up_to_u8250p(port); + unsigned int baud, quot, fraction; + unsigned long flags; + int mode; + +#ifdef CONFIG_SERIAL_8250_DMA + if (up->dma) { + if (uart_console(port)) { + devm_kfree(up->port.dev, up->dma); + up->dma = NULL; + } else { + mtk8250_dma_enable(up); + } + } +#endif + + /* + * Store the requested baud rate before calling the generic 8250 + * set_termios method. Standard 8250 port expects bauds to be + * no higher than (uartclk / 16) so the baud will be clamped if it + * gets out of that bound. Mediatek 8250 port supports speed + * higher than that, therefore we'll get original baud rate back + * after calling the generic set_termios method and recalculate + * the speed later in this method. + */ + baud = tty_termios_baud_rate(termios); + + serial8250_do_set_termios(port, termios, NULL); + + tty_termios_encode_baud_rate(termios, baud, baud); + + /* + * Mediatek UARTs use an extra highspeed register (MTK_UART_HIGHS) + * + * We need to recalcualte the quot register, as the claculation depends + * on the vaule in the highspeed register. + * + * Some baudrates are not supported by the chip, so we use the next + * lower rate supported and update termios c_flag. + * + * If highspeed register is set to 3, we need to specify sample count + * and sample point to increase accuracy. If not, we reset the + * registers to their default values. + */ + baud = uart_get_baud_rate(port, termios, old, + port->uartclk / 16 / UART_DIV_MAX, + port->uartclk); + + if (baud < 115200) { + serial_port_out(port, MTK_UART_HIGHS, 0x0); + quot = uart_get_divisor(port, baud); + } else { + serial_port_out(port, MTK_UART_HIGHS, 0x3); + quot = DIV_ROUND_UP(port->uartclk, 256 * baud); + } + + /* + * Ok, we're now changing the port state. Do it with + * interrupts disabled. + */ + spin_lock_irqsave(&port->lock, flags); + + /* + * Update the per-port timeout. + */ + uart_update_timeout(port, termios->c_cflag, baud); + + /* set DLAB we have cval saved in up->lcr from the call to the core */ + serial_port_out(port, UART_LCR, up->lcr | UART_LCR_DLAB); + serial_dl_write(up, quot); + + /* reset DLAB */ + serial_port_out(port, UART_LCR, up->lcr); + + if (baud >= 115200) { + unsigned int tmp; + + tmp = (port->uartclk / (baud * quot)) - 1; + serial_port_out(port, MTK_UART_SAMPLE_COUNT, tmp); + serial_port_out(port, MTK_UART_SAMPLE_POINT, + (tmp >> 1) - 1); + + /*count fraction to set fractoin register */ + fraction = ((port->uartclk * 100) / baud / quot) % 100; + fraction = DIV_ROUND_CLOSEST(fraction, 10); + serial_port_out(port, MTK_UART_FRACDIV_L, + fraction_L_mapping[fraction]); + serial_port_out(port, MTK_UART_FRACDIV_M, + fraction_M_mapping[fraction]); + } else { + serial_port_out(port, MTK_UART_SAMPLE_COUNT, 0x00); + serial_port_out(port, MTK_UART_SAMPLE_POINT, 0xff); + serial_port_out(port, MTK_UART_FRACDIV_L, 0x00); + serial_port_out(port, MTK_UART_FRACDIV_M, 0x00); + } + + if ((termios->c_cflag & CRTSCTS) && (!(termios->c_iflag & CRTSCTS))) + mode = MTK_UART_FC_HW; + else if (termios->c_iflag & CRTSCTS) + mode = MTK_UART_FC_SW; + else + mode = MTK_UART_FC_NONE; + + mtk8250_set_flow_ctrl(up, mode); + + if (uart_console(port)) + up->port.cons->cflag = termios->c_cflag; + + 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 int __maybe_unused mtk8250_runtime_suspend(struct device *dev) +{ + struct mtk8250_data *data = dev_get_drvdata(dev); + struct uart_8250_port *up = serial8250_get_port(data->line); + + /* wait until UART in idle status */ + while + (serial_in(up, MTK_UART_DEBUG0)); + + clk_disable_unprepare(data->bus_clk); + + return 0; +} + +static int __maybe_unused mtk8250_runtime_resume(struct device *dev) +{ + struct mtk8250_data *data = dev_get_drvdata(dev); + + clk_prepare_enable(data->bus_clk); + + return 0; +} + +static void +mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old) +{ + if (!state) + pm_runtime_get_sync(port->dev); + + serial8250_do_pm(port, state, old); + + if (state) + pm_runtime_put_sync_suspend(port->dev); +} + +#ifdef CONFIG_SERIAL_8250_DMA +static bool mtk8250_dma_filter(struct dma_chan *chan, void *param) +{ + return false; +} +#endif + +static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p, + struct mtk8250_data *data) +{ +#ifdef CONFIG_SERIAL_8250_DMA + int dmacnt; +#endif + + data->uart_clk = devm_clk_get(&pdev->dev, "baud"); + if (IS_ERR(data->uart_clk)) { + /* + * For compatibility with older device trees try unnamed + * clk when no baud clk can be found. + */ + data->uart_clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(data->uart_clk)) { + dev_warn(&pdev->dev, "Can't get uart clock\n"); + return PTR_ERR(data->uart_clk); + } + + return 0; + } + + data->bus_clk = devm_clk_get_enabled(&pdev->dev, "bus"); + if (IS_ERR(data->bus_clk)) + return PTR_ERR(data->bus_clk); + + data->dma = NULL; +#ifdef CONFIG_SERIAL_8250_DMA + dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names"); + if (dmacnt == 2) { + data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma), + GFP_KERNEL); + if (!data->dma) + return -ENOMEM; + + data->dma->fn = mtk8250_dma_filter; + data->dma->rx_size = MTK_UART_RX_SIZE; + data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER; + data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER; + } +#endif + + return 0; +} + +static int mtk8250_probe(struct platform_device *pdev) +{ + struct uart_8250_port uart = {}; + struct mtk8250_data *data; + struct resource *regs; + int irq, err; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!regs) { + dev_err(&pdev->dev, "no registers defined\n"); + return -EINVAL; + } + + uart.port.membase = devm_ioremap(&pdev->dev, regs->start, + resource_size(regs)); + if (!uart.port.membase) + return -ENOMEM; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->clk_count = 0; + + if (pdev->dev.of_node) { + err = mtk8250_probe_of(pdev, &uart.port, data); + if (err) + return err; + } else + return -ENODEV; + + spin_lock_init(&uart.port.lock); + uart.port.mapbase = regs->start; + uart.port.irq = irq; + uart.port.pm = mtk8250_do_pm; + uart.port.type = PORT_16550; + uart.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT; + uart.port.dev = &pdev->dev; + uart.port.iotype = UPIO_MEM32; + uart.port.regshift = 2; + uart.port.private_data = data; + uart.port.shutdown = mtk8250_shutdown; + uart.port.startup = mtk8250_startup; + uart.port.set_termios = mtk8250_set_termios; + uart.port.uartclk = clk_get_rate(data->uart_clk); +#ifdef CONFIG_SERIAL_8250_DMA + if (data->dma) + uart.dma = data->dma; +#endif + + /* Disable Rate Fix function */ + writel(0x0, uart.port.membase + + (MTK_UART_RATE_FIX << uart.port.regshift)); + + platform_set_drvdata(pdev, data); + + data->line = serial8250_register_8250_port(&uart); + if (data->line < 0) + return data->line; + + data->rx_wakeup_irq = platform_get_irq_optional(pdev, 1); + + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + + return 0; +} + +static int mtk8250_remove(struct platform_device *pdev) +{ + struct mtk8250_data *data = platform_get_drvdata(pdev); + + pm_runtime_get_sync(&pdev->dev); + + serial8250_unregister_port(data->line); + + pm_runtime_disable(&pdev->dev); + pm_runtime_put_noidle(&pdev->dev); + + return 0; +} + +static int __maybe_unused mtk8250_suspend(struct device *dev) +{ + struct mtk8250_data *data = dev_get_drvdata(dev); + int irq = data->rx_wakeup_irq; + int err; + + serial8250_suspend_port(data->line); + + pinctrl_pm_select_sleep_state(dev); + if (irq >= 0) { + err = enable_irq_wake(irq); + if (err) { + dev_err(dev, + "failed to enable irq wake on IRQ %d: %d\n", + irq, err); + pinctrl_pm_select_default_state(dev); + serial8250_resume_port(data->line); + return err; + } + } + + return 0; +} + +static int __maybe_unused mtk8250_resume(struct device *dev) +{ + struct mtk8250_data *data = dev_get_drvdata(dev); + int irq = data->rx_wakeup_irq; + + if (irq >= 0) + disable_irq_wake(irq); + pinctrl_pm_select_default_state(dev); + + serial8250_resume_port(data->line); + + return 0; +} + +static const struct dev_pm_ops mtk8250_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(mtk8250_suspend, mtk8250_resume) + SET_RUNTIME_PM_OPS(mtk8250_runtime_suspend, mtk8250_runtime_resume, + NULL) +}; + +static const struct of_device_id mtk8250_of_match[] = { + { .compatible = "mediatek,mt6577-uart" }, + { /* Sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mtk8250_of_match); + +static struct platform_driver mtk8250_platform_driver = { + .driver = { + .name = "mt6577-uart", + .pm = &mtk8250_pm_ops, + .of_match_table = mtk8250_of_match, + }, + .probe = mtk8250_probe, + .remove = mtk8250_remove, +}; +module_platform_driver(mtk8250_platform_driver); + +#ifdef CONFIG_SERIAL_8250_CONSOLE +static int __init early_mtk8250_setup(struct earlycon_device *device, + const char *options) +{ + if (!device->port.membase) + return -ENODEV; + + device->port.iotype = UPIO_MEM32; + device->port.regshift = 2; + + return early_serial8250_setup(device, NULL); +} + +OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup); +#endif + +MODULE_AUTHOR("Matthias Brugger"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Mediatek 8250 serial port driver"); -- cgit v1.2.3