diff options
Diffstat (limited to 'kernel/drivers/tty/serial/mxs-auart.c')
| -rw-r--r-- | kernel/drivers/tty/serial/mxs-auart.c | 1362 |
1 files changed, 1362 insertions, 0 deletions
diff --git a/kernel/drivers/tty/serial/mxs-auart.c b/kernel/drivers/tty/serial/mxs-auart.c new file mode 100644 index 000000000..f7e5825b5 --- /dev/null +++ b/kernel/drivers/tty/serial/mxs-auart.c @@ -0,0 +1,1362 @@ +/* + * Freescale STMP37XX/STMP378X Application UART driver + * + * Author: dmitry pervushin <dimka@embeddedalley.com> + * + * Copyright 2008-2010 Freescale Semiconductor, Inc. + * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. + * + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +#if defined(CONFIG_SERIAL_MXS_AUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) +#define SUPPORT_SYSRQ +#endif + +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/wait.h> +#include <linux/tty.h> +#include <linux/tty_driver.h> +#include <linux/tty_flip.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/platform_device.h> +#include <linux/device.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/of_device.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> + +#include <asm/cacheflush.h> + +#include <linux/gpio.h> +#include <linux/gpio/consumer.h> +#include <linux/err.h> +#include <linux/irq.h> +#include "serial_mctrl_gpio.h" + +#define MXS_AUART_PORTS 5 +#define MXS_AUART_FIFO_SIZE 16 + +#define AUART_CTRL0 0x00000000 +#define AUART_CTRL0_SET 0x00000004 +#define AUART_CTRL0_CLR 0x00000008 +#define AUART_CTRL0_TOG 0x0000000c +#define AUART_CTRL1 0x00000010 +#define AUART_CTRL1_SET 0x00000014 +#define AUART_CTRL1_CLR 0x00000018 +#define AUART_CTRL1_TOG 0x0000001c +#define AUART_CTRL2 0x00000020 +#define AUART_CTRL2_SET 0x00000024 +#define AUART_CTRL2_CLR 0x00000028 +#define AUART_CTRL2_TOG 0x0000002c +#define AUART_LINECTRL 0x00000030 +#define AUART_LINECTRL_SET 0x00000034 +#define AUART_LINECTRL_CLR 0x00000038 +#define AUART_LINECTRL_TOG 0x0000003c +#define AUART_LINECTRL2 0x00000040 +#define AUART_LINECTRL2_SET 0x00000044 +#define AUART_LINECTRL2_CLR 0x00000048 +#define AUART_LINECTRL2_TOG 0x0000004c +#define AUART_INTR 0x00000050 +#define AUART_INTR_SET 0x00000054 +#define AUART_INTR_CLR 0x00000058 +#define AUART_INTR_TOG 0x0000005c +#define AUART_DATA 0x00000060 +#define AUART_STAT 0x00000070 +#define AUART_DEBUG 0x00000080 +#define AUART_VERSION 0x00000090 +#define AUART_AUTOBAUD 0x000000a0 + +#define AUART_CTRL0_SFTRST (1 << 31) +#define AUART_CTRL0_CLKGATE (1 << 30) +#define AUART_CTRL0_RXTO_ENABLE (1 << 27) +#define AUART_CTRL0_RXTIMEOUT(v) (((v) & 0x7ff) << 16) +#define AUART_CTRL0_XFER_COUNT(v) ((v) & 0xffff) + +#define AUART_CTRL1_XFER_COUNT(v) ((v) & 0xffff) + +#define AUART_CTRL2_DMAONERR (1 << 26) +#define AUART_CTRL2_TXDMAE (1 << 25) +#define AUART_CTRL2_RXDMAE (1 << 24) + +#define AUART_CTRL2_CTSEN (1 << 15) +#define AUART_CTRL2_RTSEN (1 << 14) +#define AUART_CTRL2_RTS (1 << 11) +#define AUART_CTRL2_RXE (1 << 9) +#define AUART_CTRL2_TXE (1 << 8) +#define AUART_CTRL2_UARTEN (1 << 0) + +#define AUART_LINECTRL_BAUD_DIVINT_SHIFT 16 +#define AUART_LINECTRL_BAUD_DIVINT_MASK 0xffff0000 +#define AUART_LINECTRL_BAUD_DIVINT(v) (((v) & 0xffff) << 16) +#define AUART_LINECTRL_BAUD_DIVFRAC_SHIFT 8 +#define AUART_LINECTRL_BAUD_DIVFRAC_MASK 0x00003f00 +#define AUART_LINECTRL_BAUD_DIVFRAC(v) (((v) & 0x3f) << 8) +#define AUART_LINECTRL_WLEN_MASK 0x00000060 +#define AUART_LINECTRL_WLEN(v) (((v) & 0x3) << 5) +#define AUART_LINECTRL_FEN (1 << 4) +#define AUART_LINECTRL_STP2 (1 << 3) +#define AUART_LINECTRL_EPS (1 << 2) +#define AUART_LINECTRL_PEN (1 << 1) +#define AUART_LINECTRL_BRK (1 << 0) + +#define AUART_INTR_RTIEN (1 << 22) +#define AUART_INTR_TXIEN (1 << 21) +#define AUART_INTR_RXIEN (1 << 20) +#define AUART_INTR_CTSMIEN (1 << 17) +#define AUART_INTR_RTIS (1 << 6) +#define AUART_INTR_TXIS (1 << 5) +#define AUART_INTR_RXIS (1 << 4) +#define AUART_INTR_CTSMIS (1 << 1) + +#define AUART_STAT_BUSY (1 << 29) +#define AUART_STAT_CTS (1 << 28) +#define AUART_STAT_TXFE (1 << 27) +#define AUART_STAT_TXFF (1 << 25) +#define AUART_STAT_RXFE (1 << 24) +#define AUART_STAT_OERR (1 << 19) +#define AUART_STAT_BERR (1 << 18) +#define AUART_STAT_PERR (1 << 17) +#define AUART_STAT_FERR (1 << 16) +#define AUART_STAT_RXCOUNT_MASK 0xffff + +static struct uart_driver auart_driver; + +enum mxs_auart_type { + IMX23_AUART, + IMX28_AUART, +}; + +struct mxs_auart_port { + struct uart_port port; + +#define MXS_AUART_DMA_ENABLED 0x2 +#define MXS_AUART_DMA_TX_SYNC 2 /* bit 2 */ +#define MXS_AUART_DMA_RX_READY 3 /* bit 3 */ +#define MXS_AUART_RTSCTS 4 /* bit 4 */ + unsigned long flags; + unsigned int mctrl_prev; + enum mxs_auart_type devtype; + + struct clk *clk; + struct device *dev; + + /* for DMA */ + struct scatterlist tx_sgl; + struct dma_chan *tx_dma_chan; + void *tx_dma_buf; + + struct scatterlist rx_sgl; + struct dma_chan *rx_dma_chan; + void *rx_dma_buf; + + struct mctrl_gpios *gpios; + int gpio_irq[UART_GPIO_MAX]; + bool ms_irq_enabled; +}; + +static struct platform_device_id mxs_auart_devtype[] = { + { .name = "mxs-auart-imx23", .driver_data = IMX23_AUART }, + { .name = "mxs-auart-imx28", .driver_data = IMX28_AUART }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(platform, mxs_auart_devtype); + +static const struct of_device_id mxs_auart_dt_ids[] = { + { + .compatible = "fsl,imx28-auart", + .data = &mxs_auart_devtype[IMX28_AUART] + }, { + .compatible = "fsl,imx23-auart", + .data = &mxs_auart_devtype[IMX23_AUART] + }, { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, mxs_auart_dt_ids); + +static inline int is_imx28_auart(struct mxs_auart_port *s) +{ + return s->devtype == IMX28_AUART; +} + +static inline bool auart_dma_enabled(struct mxs_auart_port *s) +{ + return s->flags & MXS_AUART_DMA_ENABLED; +} + +static void mxs_auart_stop_tx(struct uart_port *u); + +#define to_auart_port(u) container_of(u, struct mxs_auart_port, port) + +static void mxs_auart_tx_chars(struct mxs_auart_port *s); + +static void dma_tx_callback(void *param) +{ + struct mxs_auart_port *s = param; + struct circ_buf *xmit = &s->port.state->xmit; + + dma_unmap_sg(s->dev, &s->tx_sgl, 1, DMA_TO_DEVICE); + + /* clear the bit used to serialize the DMA tx. */ + clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags); + smp_mb__after_atomic(); + + /* wake up the possible processes. */ + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&s->port); + + mxs_auart_tx_chars(s); +} + +static int mxs_auart_dma_tx(struct mxs_auart_port *s, int size) +{ + struct dma_async_tx_descriptor *desc; + struct scatterlist *sgl = &s->tx_sgl; + struct dma_chan *channel = s->tx_dma_chan; + u32 pio; + + /* [1] : send PIO. Note, the first pio word is CTRL1. */ + pio = AUART_CTRL1_XFER_COUNT(size); + desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)&pio, + 1, DMA_TRANS_NONE, 0); + if (!desc) { + dev_err(s->dev, "step 1 error\n"); + return -EINVAL; + } + + /* [2] : set DMA buffer. */ + sg_init_one(sgl, s->tx_dma_buf, size); + dma_map_sg(s->dev, sgl, 1, DMA_TO_DEVICE); + desc = dmaengine_prep_slave_sg(channel, sgl, + 1, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_err(s->dev, "step 2 error\n"); + return -EINVAL; + } + + /* [3] : submit the DMA */ + desc->callback = dma_tx_callback; + desc->callback_param = s; + dmaengine_submit(desc); + dma_async_issue_pending(channel); + return 0; +} + +static void mxs_auart_tx_chars(struct mxs_auart_port *s) +{ + struct circ_buf *xmit = &s->port.state->xmit; + + if (auart_dma_enabled(s)) { + u32 i = 0; + int size; + void *buffer = s->tx_dma_buf; + + if (test_and_set_bit(MXS_AUART_DMA_TX_SYNC, &s->flags)) + return; + + while (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) { + size = min_t(u32, UART_XMIT_SIZE - i, + CIRC_CNT_TO_END(xmit->head, + xmit->tail, + UART_XMIT_SIZE)); + memcpy(buffer + i, xmit->buf + xmit->tail, size); + xmit->tail = (xmit->tail + size) & (UART_XMIT_SIZE - 1); + + i += size; + if (i >= UART_XMIT_SIZE) + break; + } + + if (uart_tx_stopped(&s->port)) + mxs_auart_stop_tx(&s->port); + + if (i) { + mxs_auart_dma_tx(s, i); + } else { + clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags); + smp_mb__after_atomic(); + } + return; + } + + + while (!(readl(s->port.membase + AUART_STAT) & + AUART_STAT_TXFF)) { + if (s->port.x_char) { + s->port.icount.tx++; + writel(s->port.x_char, + s->port.membase + AUART_DATA); + s->port.x_char = 0; + continue; + } + if (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) { + s->port.icount.tx++; + writel(xmit->buf[xmit->tail], + s->port.membase + AUART_DATA); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + } else + break; + } + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&s->port); + + if (uart_circ_empty(&(s->port.state->xmit))) + writel(AUART_INTR_TXIEN, + s->port.membase + AUART_INTR_CLR); + else + writel(AUART_INTR_TXIEN, + s->port.membase + AUART_INTR_SET); + + if (uart_tx_stopped(&s->port)) + mxs_auart_stop_tx(&s->port); +} + +static void mxs_auart_rx_char(struct mxs_auart_port *s) +{ + int flag; + u32 stat; + u8 c; + + c = readl(s->port.membase + AUART_DATA); + stat = readl(s->port.membase + AUART_STAT); + + flag = TTY_NORMAL; + s->port.icount.rx++; + + if (stat & AUART_STAT_BERR) { + s->port.icount.brk++; + if (uart_handle_break(&s->port)) + goto out; + } else if (stat & AUART_STAT_PERR) { + s->port.icount.parity++; + } else if (stat & AUART_STAT_FERR) { + s->port.icount.frame++; + } + + /* + * Mask off conditions which should be ingored. + */ + stat &= s->port.read_status_mask; + + if (stat & AUART_STAT_BERR) { + flag = TTY_BREAK; + } else if (stat & AUART_STAT_PERR) + flag = TTY_PARITY; + else if (stat & AUART_STAT_FERR) + flag = TTY_FRAME; + + if (stat & AUART_STAT_OERR) + s->port.icount.overrun++; + + if (uart_handle_sysrq_char(&s->port, c)) + goto out; + + uart_insert_char(&s->port, stat, AUART_STAT_OERR, c, flag); +out: + writel(stat, s->port.membase + AUART_STAT); +} + +static void mxs_auart_rx_chars(struct mxs_auart_port *s) +{ + u32 stat = 0; + + for (;;) { + stat = readl(s->port.membase + AUART_STAT); + if (stat & AUART_STAT_RXFE) + break; + mxs_auart_rx_char(s); + } + + writel(stat, s->port.membase + AUART_STAT); + tty_flip_buffer_push(&s->port.state->port); +} + +static int mxs_auart_request_port(struct uart_port *u) +{ + return 0; +} + +static int mxs_auart_verify_port(struct uart_port *u, + struct serial_struct *ser) +{ + if (u->type != PORT_UNKNOWN && u->type != PORT_IMX) + return -EINVAL; + return 0; +} + +static void mxs_auart_config_port(struct uart_port *u, int flags) +{ +} + +static const char *mxs_auart_type(struct uart_port *u) +{ + struct mxs_auart_port *s = to_auart_port(u); + + return dev_name(s->dev); +} + +static void mxs_auart_release_port(struct uart_port *u) +{ +} + +static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl) +{ + struct mxs_auart_port *s = to_auart_port(u); + + u32 ctrl = readl(u->membase + AUART_CTRL2); + + ctrl &= ~(AUART_CTRL2_RTSEN | AUART_CTRL2_RTS); + if (mctrl & TIOCM_RTS) { + if (uart_cts_enabled(u)) + ctrl |= AUART_CTRL2_RTSEN; + else + ctrl |= AUART_CTRL2_RTS; + } + + writel(ctrl, u->membase + AUART_CTRL2); + + mctrl_gpio_set(s->gpios, mctrl); +} + +#define MCTRL_ANY_DELTA (TIOCM_RI | TIOCM_DSR | TIOCM_CD | TIOCM_CTS) +static u32 mxs_auart_modem_status(struct mxs_auart_port *s, u32 mctrl) +{ + u32 mctrl_diff; + + mctrl_diff = mctrl ^ s->mctrl_prev; + s->mctrl_prev = mctrl; + if (mctrl_diff & MCTRL_ANY_DELTA && s->ms_irq_enabled && + s->port.state != NULL) { + if (mctrl_diff & TIOCM_RI) + s->port.icount.rng++; + if (mctrl_diff & TIOCM_DSR) + s->port.icount.dsr++; + if (mctrl_diff & TIOCM_CD) + uart_handle_dcd_change(&s->port, mctrl & TIOCM_CD); + if (mctrl_diff & TIOCM_CTS) + uart_handle_cts_change(&s->port, mctrl & TIOCM_CTS); + + wake_up_interruptible(&s->port.state->port.delta_msr_wait); + } + return mctrl; +} + +static u32 mxs_auart_get_mctrl(struct uart_port *u) +{ + struct mxs_auart_port *s = to_auart_port(u); + u32 stat = readl(u->membase + AUART_STAT); + u32 mctrl = 0; + + if (stat & AUART_STAT_CTS) + mctrl |= TIOCM_CTS; + + return mctrl_gpio_get(s->gpios, &mctrl); +} + +/* + * Enable modem status interrupts + */ +static void mxs_auart_enable_ms(struct uart_port *port) +{ + struct mxs_auart_port *s = to_auart_port(port); + + /* + * Interrupt should not be enabled twice + */ + if (s->ms_irq_enabled) + return; + + s->ms_irq_enabled = true; + + if (s->gpio_irq[UART_GPIO_CTS] >= 0) + enable_irq(s->gpio_irq[UART_GPIO_CTS]); + /* TODO: enable AUART_INTR_CTSMIEN otherwise */ + + if (s->gpio_irq[UART_GPIO_DSR] >= 0) + enable_irq(s->gpio_irq[UART_GPIO_DSR]); + + if (s->gpio_irq[UART_GPIO_RI] >= 0) + enable_irq(s->gpio_irq[UART_GPIO_RI]); + + if (s->gpio_irq[UART_GPIO_DCD] >= 0) + enable_irq(s->gpio_irq[UART_GPIO_DCD]); +} + +/* + * Disable modem status interrupts + */ +static void mxs_auart_disable_ms(struct uart_port *port) +{ + struct mxs_auart_port *s = to_auart_port(port); + + /* + * Interrupt should not be disabled twice + */ + if (!s->ms_irq_enabled) + return; + + s->ms_irq_enabled = false; + + if (s->gpio_irq[UART_GPIO_CTS] >= 0) + disable_irq(s->gpio_irq[UART_GPIO_CTS]); + /* TODO: disable AUART_INTR_CTSMIEN otherwise */ + + if (s->gpio_irq[UART_GPIO_DSR] >= 0) + disable_irq(s->gpio_irq[UART_GPIO_DSR]); + + if (s->gpio_irq[UART_GPIO_RI] >= 0) + disable_irq(s->gpio_irq[UART_GPIO_RI]); + + if (s->gpio_irq[UART_GPIO_DCD] >= 0) + disable_irq(s->gpio_irq[UART_GPIO_DCD]); +} + +static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s); +static void dma_rx_callback(void *arg) +{ + struct mxs_auart_port *s = (struct mxs_auart_port *) arg; + struct tty_port *port = &s->port.state->port; + int count; + u32 stat; + + dma_unmap_sg(s->dev, &s->rx_sgl, 1, DMA_FROM_DEVICE); + + stat = readl(s->port.membase + AUART_STAT); + stat &= ~(AUART_STAT_OERR | AUART_STAT_BERR | + AUART_STAT_PERR | AUART_STAT_FERR); + + count = stat & AUART_STAT_RXCOUNT_MASK; + tty_insert_flip_string(port, s->rx_dma_buf, count); + + writel(stat, s->port.membase + AUART_STAT); + tty_flip_buffer_push(port); + + /* start the next DMA for RX. */ + mxs_auart_dma_prep_rx(s); +} + +static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s) +{ + struct dma_async_tx_descriptor *desc; + struct scatterlist *sgl = &s->rx_sgl; + struct dma_chan *channel = s->rx_dma_chan; + u32 pio[1]; + + /* [1] : send PIO */ + pio[0] = AUART_CTRL0_RXTO_ENABLE + | AUART_CTRL0_RXTIMEOUT(0x80) + | AUART_CTRL0_XFER_COUNT(UART_XMIT_SIZE); + desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio, + 1, DMA_TRANS_NONE, 0); + if (!desc) { + dev_err(s->dev, "step 1 error\n"); + return -EINVAL; + } + + /* [2] : send DMA request */ + sg_init_one(sgl, s->rx_dma_buf, UART_XMIT_SIZE); + dma_map_sg(s->dev, sgl, 1, DMA_FROM_DEVICE); + desc = dmaengine_prep_slave_sg(channel, sgl, 1, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + dev_err(s->dev, "step 2 error\n"); + return -1; + } + + /* [3] : submit the DMA, but do not issue it. */ + desc->callback = dma_rx_callback; + desc->callback_param = s; + dmaengine_submit(desc); + dma_async_issue_pending(channel); + return 0; +} + +static void mxs_auart_dma_exit_channel(struct mxs_auart_port *s) +{ + if (s->tx_dma_chan) { + dma_release_channel(s->tx_dma_chan); + s->tx_dma_chan = NULL; + } + if (s->rx_dma_chan) { + dma_release_channel(s->rx_dma_chan); + s->rx_dma_chan = NULL; + } + + kfree(s->tx_dma_buf); + kfree(s->rx_dma_buf); + s->tx_dma_buf = NULL; + s->rx_dma_buf = NULL; +} + +static void mxs_auart_dma_exit(struct mxs_auart_port *s) +{ + + writel(AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE | AUART_CTRL2_DMAONERR, + s->port.membase + AUART_CTRL2_CLR); + + mxs_auart_dma_exit_channel(s); + s->flags &= ~MXS_AUART_DMA_ENABLED; + clear_bit(MXS_AUART_DMA_TX_SYNC, &s->flags); + clear_bit(MXS_AUART_DMA_RX_READY, &s->flags); +} + +static int mxs_auart_dma_init(struct mxs_auart_port *s) +{ + if (auart_dma_enabled(s)) + return 0; + + /* init for RX */ + s->rx_dma_chan = dma_request_slave_channel(s->dev, "rx"); + if (!s->rx_dma_chan) + goto err_out; + s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA); + if (!s->rx_dma_buf) + goto err_out; + + /* init for TX */ + s->tx_dma_chan = dma_request_slave_channel(s->dev, "tx"); + if (!s->tx_dma_chan) + goto err_out; + s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA); + if (!s->tx_dma_buf) + goto err_out; + + /* set the flags */ + s->flags |= MXS_AUART_DMA_ENABLED; + dev_dbg(s->dev, "enabled the DMA support."); + + /* The DMA buffer is now the FIFO the TTY subsystem can use */ + s->port.fifosize = UART_XMIT_SIZE; + + return 0; + +err_out: + mxs_auart_dma_exit_channel(s); + return -EINVAL; + +} + +#define RTS_AT_AUART() IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(s->gpios, \ + UART_GPIO_RTS)) +#define CTS_AT_AUART() IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(s->gpios, \ + UART_GPIO_CTS)) +static void mxs_auart_settermios(struct uart_port *u, + struct ktermios *termios, + struct ktermios *old) +{ + struct mxs_auart_port *s = to_auart_port(u); + u32 bm, ctrl, ctrl2, div; + unsigned int cflag, baud; + + cflag = termios->c_cflag; + + ctrl = AUART_LINECTRL_FEN; + ctrl2 = readl(u->membase + AUART_CTRL2); + + /* byte size */ + switch (cflag & CSIZE) { + case CS5: + bm = 0; + break; + case CS6: + bm = 1; + break; + case CS7: + bm = 2; + break; + case CS8: + bm = 3; + break; + default: + return; + } + + ctrl |= AUART_LINECTRL_WLEN(bm); + + /* parity */ + if (cflag & PARENB) { + ctrl |= AUART_LINECTRL_PEN; + if ((cflag & PARODD) == 0) + ctrl |= AUART_LINECTRL_EPS; + } + + u->read_status_mask = 0; + + if (termios->c_iflag & INPCK) + u->read_status_mask |= AUART_STAT_PERR; + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + u->read_status_mask |= AUART_STAT_BERR; + + /* + * Characters to ignore + */ + u->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + u->ignore_status_mask |= AUART_STAT_PERR; + if (termios->c_iflag & IGNBRK) { + u->ignore_status_mask |= AUART_STAT_BERR; + /* + * If we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + u->ignore_status_mask |= AUART_STAT_OERR; + } + + /* + * ignore all characters if CREAD is not set + */ + if (cflag & CREAD) + ctrl2 |= AUART_CTRL2_RXE; + else + ctrl2 &= ~AUART_CTRL2_RXE; + + /* figure out the stop bits requested */ + if (cflag & CSTOPB) + ctrl |= AUART_LINECTRL_STP2; + + /* figure out the hardware flow control settings */ + ctrl2 &= ~(AUART_CTRL2_CTSEN | AUART_CTRL2_RTSEN); + if (cflag & CRTSCTS) { + /* + * The DMA has a bug(see errata:2836) in mx23. + * So we can not implement the DMA for auart in mx23, + * we can only implement the DMA support for auart + * in mx28. + */ + if (is_imx28_auart(s) + && test_bit(MXS_AUART_RTSCTS, &s->flags)) { + if (!mxs_auart_dma_init(s)) + /* enable DMA tranfer */ + ctrl2 |= AUART_CTRL2_TXDMAE | AUART_CTRL2_RXDMAE + | AUART_CTRL2_DMAONERR; + } + /* Even if RTS is GPIO line RTSEN can be enabled because + * the pinctrl configuration decides about RTS pin function */ + ctrl2 |= AUART_CTRL2_RTSEN; + if (CTS_AT_AUART()) + ctrl2 |= AUART_CTRL2_CTSEN; + } + + /* set baud rate */ + baud = uart_get_baud_rate(u, termios, old, 0, u->uartclk); + div = u->uartclk * 32 / baud; + ctrl |= AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F); + ctrl |= AUART_LINECTRL_BAUD_DIVINT(div >> 6); + + writel(ctrl, u->membase + AUART_LINECTRL); + writel(ctrl2, u->membase + AUART_CTRL2); + + uart_update_timeout(u, termios->c_cflag, baud); + + /* prepare for the DMA RX. */ + if (auart_dma_enabled(s) && + !test_and_set_bit(MXS_AUART_DMA_RX_READY, &s->flags)) { + if (!mxs_auart_dma_prep_rx(s)) { + /* Disable the normal RX interrupt. */ + writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN, + u->membase + AUART_INTR_CLR); + } else { + mxs_auart_dma_exit(s); + dev_err(s->dev, "We can not start up the DMA.\n"); + } + } + + /* CTS flow-control and modem-status interrupts */ + if (UART_ENABLE_MS(u, termios->c_cflag)) + mxs_auart_enable_ms(u); + else + mxs_auart_disable_ms(u); +} + +static void mxs_auart_set_ldisc(struct uart_port *port, + struct ktermios *termios) +{ + if (termios->c_line == N_PPS) { + port->flags |= UPF_HARDPPS_CD; + mxs_auart_enable_ms(port); + } else { + port->flags &= ~UPF_HARDPPS_CD; + } +} + +static irqreturn_t mxs_auart_irq_handle(int irq, void *context) +{ + u32 istat; + struct mxs_auart_port *s = context; + u32 mctrl_temp = s->mctrl_prev; + u32 stat = readl(s->port.membase + AUART_STAT); + + istat = readl(s->port.membase + AUART_INTR); + + /* ack irq */ + writel(istat & (AUART_INTR_RTIS + | AUART_INTR_TXIS + | AUART_INTR_RXIS + | AUART_INTR_CTSMIS), + s->port.membase + AUART_INTR_CLR); + + /* + * Dealing with GPIO interrupt + */ + if (irq == s->gpio_irq[UART_GPIO_CTS] || + irq == s->gpio_irq[UART_GPIO_DCD] || + irq == s->gpio_irq[UART_GPIO_DSR] || + irq == s->gpio_irq[UART_GPIO_RI]) + mxs_auart_modem_status(s, + mctrl_gpio_get(s->gpios, &mctrl_temp)); + + if (istat & AUART_INTR_CTSMIS) { + if (CTS_AT_AUART() && s->ms_irq_enabled) + uart_handle_cts_change(&s->port, + stat & AUART_STAT_CTS); + writel(AUART_INTR_CTSMIS, + s->port.membase + AUART_INTR_CLR); + istat &= ~AUART_INTR_CTSMIS; + } + + if (istat & (AUART_INTR_RTIS | AUART_INTR_RXIS)) { + if (!auart_dma_enabled(s)) + mxs_auart_rx_chars(s); + istat &= ~(AUART_INTR_RTIS | AUART_INTR_RXIS); + } + + if (istat & AUART_INTR_TXIS) { + mxs_auart_tx_chars(s); + istat &= ~AUART_INTR_TXIS; + } + + return IRQ_HANDLED; +} + +static void mxs_auart_reset(struct uart_port *u) +{ + int i; + unsigned int reg; + + writel(AUART_CTRL0_SFTRST, u->membase + AUART_CTRL0_CLR); + + for (i = 0; i < 10000; i++) { + reg = readl(u->membase + AUART_CTRL0); + if (!(reg & AUART_CTRL0_SFTRST)) + break; + udelay(3); + } + writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR); +} + +static int mxs_auart_startup(struct uart_port *u) +{ + int ret; + struct mxs_auart_port *s = to_auart_port(u); + + ret = clk_prepare_enable(s->clk); + if (ret) + return ret; + + writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR); + + writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_SET); + + writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN, + u->membase + AUART_INTR); + + /* Reset FIFO size (it could have changed if DMA was enabled) */ + u->fifosize = MXS_AUART_FIFO_SIZE; + + /* + * Enable fifo so all four bytes of a DMA word are written to + * output (otherwise, only the LSB is written, ie. 1 in 4 bytes) + */ + writel(AUART_LINECTRL_FEN, u->membase + AUART_LINECTRL_SET); + + /* get initial status of modem lines */ + mctrl_gpio_get(s->gpios, &s->mctrl_prev); + + s->ms_irq_enabled = false; + return 0; +} + +static void mxs_auart_shutdown(struct uart_port *u) +{ + struct mxs_auart_port *s = to_auart_port(u); + + mxs_auart_disable_ms(u); + + if (auart_dma_enabled(s)) + mxs_auart_dma_exit(s); + + writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_CLR); + + writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN, + u->membase + AUART_INTR_CLR); + + writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_SET); + + clk_disable_unprepare(s->clk); +} + +static unsigned int mxs_auart_tx_empty(struct uart_port *u) +{ + if ((readl(u->membase + AUART_STAT) & + (AUART_STAT_TXFE | AUART_STAT_BUSY)) == AUART_STAT_TXFE) + return TIOCSER_TEMT; + + return 0; +} + +static void mxs_auart_start_tx(struct uart_port *u) +{ + struct mxs_auart_port *s = to_auart_port(u); + + /* enable transmitter */ + writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_SET); + + mxs_auart_tx_chars(s); +} + +static void mxs_auart_stop_tx(struct uart_port *u) +{ + writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_CLR); +} + +static void mxs_auart_stop_rx(struct uart_port *u) +{ + writel(AUART_CTRL2_RXE, u->membase + AUART_CTRL2_CLR); +} + +static void mxs_auart_break_ctl(struct uart_port *u, int ctl) +{ + if (ctl) + writel(AUART_LINECTRL_BRK, + u->membase + AUART_LINECTRL_SET); + else + writel(AUART_LINECTRL_BRK, + u->membase + AUART_LINECTRL_CLR); +} + +static struct uart_ops mxs_auart_ops = { + .tx_empty = mxs_auart_tx_empty, + .start_tx = mxs_auart_start_tx, + .stop_tx = mxs_auart_stop_tx, + .stop_rx = mxs_auart_stop_rx, + .enable_ms = mxs_auart_enable_ms, + .break_ctl = mxs_auart_break_ctl, + .set_mctrl = mxs_auart_set_mctrl, + .get_mctrl = mxs_auart_get_mctrl, + .startup = mxs_auart_startup, + .shutdown = mxs_auart_shutdown, + .set_termios = mxs_auart_settermios, + .set_ldisc = mxs_auart_set_ldisc, + .type = mxs_auart_type, + .release_port = mxs_auart_release_port, + .request_port = mxs_auart_request_port, + .config_port = mxs_auart_config_port, + .verify_port = mxs_auart_verify_port, +}; + +static struct mxs_auart_port *auart_port[MXS_AUART_PORTS]; + +#ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE +static void mxs_auart_console_putchar(struct uart_port *port, int ch) +{ + unsigned int to = 1000; + + while (readl(port->membase + AUART_STAT) & AUART_STAT_TXFF) { + if (!to--) + break; + udelay(1); + } + + writel(ch, port->membase + AUART_DATA); +} + +static void +auart_console_write(struct console *co, const char *str, unsigned int count) +{ + struct mxs_auart_port *s; + struct uart_port *port; + unsigned int old_ctrl0, old_ctrl2; + unsigned int to = 20000; + + if (co->index >= MXS_AUART_PORTS || co->index < 0) + return; + + s = auart_port[co->index]; + port = &s->port; + + clk_enable(s->clk); + + /* First save the CR then disable the interrupts */ + old_ctrl2 = readl(port->membase + AUART_CTRL2); + old_ctrl0 = readl(port->membase + AUART_CTRL0); + + writel(AUART_CTRL0_CLKGATE, + port->membase + AUART_CTRL0_CLR); + writel(AUART_CTRL2_UARTEN | AUART_CTRL2_TXE, + port->membase + AUART_CTRL2_SET); + + uart_console_write(port, str, count, mxs_auart_console_putchar); + + /* Finally, wait for transmitter to become empty ... */ + while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) { + udelay(1); + if (!to--) + break; + } + + /* + * ... and restore the TCR if we waited long enough for the transmitter + * to be idle. This might keep the transmitter enabled although it is + * unused, but that is better than to disable it while it is still + * transmitting. + */ + if (!(readl(port->membase + AUART_STAT) & AUART_STAT_BUSY)) { + writel(old_ctrl0, port->membase + AUART_CTRL0); + writel(old_ctrl2, port->membase + AUART_CTRL2); + } + + clk_disable(s->clk); +} + +static void __init +auart_console_get_options(struct uart_port *port, int *baud, + int *parity, int *bits) +{ + unsigned int lcr_h, quot; + + if (!(readl(port->membase + AUART_CTRL2) & AUART_CTRL2_UARTEN)) + return; + + lcr_h = readl(port->membase + AUART_LINECTRL); + + *parity = 'n'; + if (lcr_h & AUART_LINECTRL_PEN) { + if (lcr_h & AUART_LINECTRL_EPS) + *parity = 'e'; + else + *parity = 'o'; + } + + if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(2)) + *bits = 7; + else + *bits = 8; + + quot = ((readl(port->membase + AUART_LINECTRL) + & AUART_LINECTRL_BAUD_DIVINT_MASK)) + >> (AUART_LINECTRL_BAUD_DIVINT_SHIFT - 6); + quot |= ((readl(port->membase + AUART_LINECTRL) + & AUART_LINECTRL_BAUD_DIVFRAC_MASK)) + >> AUART_LINECTRL_BAUD_DIVFRAC_SHIFT; + if (quot == 0) + quot = 1; + + *baud = (port->uartclk << 2) / quot; +} + +static int __init +auart_console_setup(struct console *co, char *options) +{ + struct mxs_auart_port *s; + int baud = 9600; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + int ret; + + /* + * 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(auart_port)) + co->index = 0; + s = auart_port[co->index]; + if (!s) + return -ENODEV; + + ret = clk_prepare_enable(s->clk); + if (ret) + return ret; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + else + auart_console_get_options(&s->port, &baud, &parity, &bits); + + ret = uart_set_options(&s->port, co, baud, parity, bits, flow); + + clk_disable_unprepare(s->clk); + + return ret; +} + +static struct console auart_console = { + .name = "ttyAPP", + .write = auart_console_write, + .device = uart_console_device, + .setup = auart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &auart_driver, +}; +#endif + +static struct uart_driver auart_driver = { + .owner = THIS_MODULE, + .driver_name = "ttyAPP", + .dev_name = "ttyAPP", + .major = 0, + .minor = 0, + .nr = MXS_AUART_PORTS, +#ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE + .cons = &auart_console, +#endif +}; + +/* + * This function returns 1 if pdev isn't a device instatiated by dt, 0 if it + * could successfully get all information from dt or a negative errno. + */ +static int serial_mxs_probe_dt(struct mxs_auart_port *s, + struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + int ret; + + if (!np) + /* no device tree device */ + return 1; + + ret = of_alias_get_id(np, "serial"); + if (ret < 0) { + dev_err(&pdev->dev, "failed to get alias id: %d\n", ret); + return ret; + } + s->port.line = ret; + + if (of_get_property(np, "fsl,uart-has-rtscts", NULL)) + set_bit(MXS_AUART_RTSCTS, &s->flags); + + return 0; +} + +static int mxs_auart_init_gpios(struct mxs_auart_port *s, struct device *dev) +{ + enum mctrl_gpio_idx i; + struct gpio_desc *gpiod; + + s->gpios = mctrl_gpio_init(dev, 0); + if (IS_ERR(s->gpios)) + return PTR_ERR(s->gpios); + + /* Block (enabled before) DMA option if RTS or CTS is GPIO line */ + if (!RTS_AT_AUART() || !CTS_AT_AUART()) { + if (test_bit(MXS_AUART_RTSCTS, &s->flags)) + dev_warn(dev, + "DMA and flow control via gpio may cause some problems. DMA disabled!\n"); + clear_bit(MXS_AUART_RTSCTS, &s->flags); + } + + for (i = 0; i < UART_GPIO_MAX; i++) { + gpiod = mctrl_gpio_to_gpiod(s->gpios, i); + if (gpiod && (gpiod_get_direction(gpiod) == GPIOF_DIR_IN)) + s->gpio_irq[i] = gpiod_to_irq(gpiod); + else + s->gpio_irq[i] = -EINVAL; + } + + return 0; +} + +static void mxs_auart_free_gpio_irq(struct mxs_auart_port *s) +{ + enum mctrl_gpio_idx i; + + for (i = 0; i < UART_GPIO_MAX; i++) + if (s->gpio_irq[i] >= 0) + free_irq(s->gpio_irq[i], s); +} + +static int mxs_auart_request_gpio_irq(struct mxs_auart_port *s) +{ + int *irq = s->gpio_irq; + enum mctrl_gpio_idx i; + int err = 0; + + for (i = 0; (i < UART_GPIO_MAX) && !err; i++) { + if (irq[i] < 0) + continue; + + irq_set_status_flags(irq[i], IRQ_NOAUTOEN); + err = request_irq(irq[i], mxs_auart_irq_handle, + IRQ_TYPE_EDGE_BOTH, dev_name(s->dev), s); + if (err) + dev_err(s->dev, "%s - Can't get %d irq\n", + __func__, irq[i]); + } + + /* + * If something went wrong, rollback. + */ + while (err && (--i >= 0)) + if (irq[i] >= 0) + free_irq(irq[i], s); + + return err; +} + +static int mxs_auart_probe(struct platform_device *pdev) +{ + const struct of_device_id *of_id = + of_match_device(mxs_auart_dt_ids, &pdev->dev); + struct mxs_auart_port *s; + u32 version; + int ret, irq; + struct resource *r; + + s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL); + if (!s) + return -ENOMEM; + + ret = serial_mxs_probe_dt(s, pdev); + if (ret > 0) + s->port.line = pdev->id < 0 ? 0 : pdev->id; + else if (ret < 0) + return ret; + + if (of_id) { + pdev->id_entry = of_id->data; + s->devtype = pdev->id_entry->driver_data; + } + + s->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(s->clk)) + return PTR_ERR(s->clk); + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!r) + return -ENXIO; + + + s->port.mapbase = r->start; + s->port.membase = ioremap(r->start, resource_size(r)); + s->port.ops = &mxs_auart_ops; + s->port.iotype = UPIO_MEM; + s->port.fifosize = MXS_AUART_FIFO_SIZE; + s->port.uartclk = clk_get_rate(s->clk); + s->port.type = PORT_IMX; + s->port.dev = s->dev = &pdev->dev; + + s->mctrl_prev = 0; + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + s->port.irq = irq; + ret = devm_request_irq(&pdev->dev, irq, mxs_auart_irq_handle, 0, + dev_name(&pdev->dev), s); + if (ret) + return ret; + + platform_set_drvdata(pdev, s); + + ret = mxs_auart_init_gpios(s, &pdev->dev); + if (ret) { + dev_err(&pdev->dev, "Failed to initialize GPIOs.\n"); + return ret; + } + + /* + * Get the GPIO lines IRQ + */ + ret = mxs_auart_request_gpio_irq(s); + if (ret) + return ret; + + auart_port[s->port.line] = s; + + mxs_auart_reset(&s->port); + + ret = uart_add_one_port(&auart_driver, &s->port); + if (ret) + goto out_free_gpio_irq; + + version = readl(s->port.membase + AUART_VERSION); + dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n", + (version >> 24) & 0xff, + (version >> 16) & 0xff, version & 0xffff); + + return 0; + +out_free_gpio_irq: + mxs_auart_free_gpio_irq(s); + auart_port[pdev->id] = NULL; + return ret; +} + +static int mxs_auart_remove(struct platform_device *pdev) +{ + struct mxs_auart_port *s = platform_get_drvdata(pdev); + + uart_remove_one_port(&auart_driver, &s->port); + auart_port[pdev->id] = NULL; + mxs_auart_free_gpio_irq(s); + + return 0; +} + +static struct platform_driver mxs_auart_driver = { + .probe = mxs_auart_probe, + .remove = mxs_auart_remove, + .driver = { + .name = "mxs-auart", + .of_match_table = mxs_auart_dt_ids, + }, +}; + +static int __init mxs_auart_init(void) +{ + int r; + + r = uart_register_driver(&auart_driver); + if (r) + goto out; + + r = platform_driver_register(&mxs_auart_driver); + if (r) + goto out_err; + + return 0; +out_err: + uart_unregister_driver(&auart_driver); +out: + return r; +} + +static void __exit mxs_auart_exit(void) +{ + platform_driver_unregister(&mxs_auart_driver); + uart_unregister_driver(&auart_driver); +} + +module_init(mxs_auart_init); +module_exit(mxs_auart_exit); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Freescale MXS application uart driver"); +MODULE_ALIAS("platform:mxs-auart"); |