diff options
Diffstat (limited to 'drivers/tty/serial/msm_serial.c')
| -rw-r--r-- | drivers/tty/serial/msm_serial.c | 882 |
1 files changed, 797 insertions, 85 deletions
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index b73889c8e..7312e7e01 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -19,25 +19,147 @@ # define SUPPORT_SYSRQ #endif +#include <linux/kernel.h> #include <linux/atomic.h> -#include <linux/hrtimer.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> #include <linux/module.h> #include <linux/io.h> #include <linux/ioport.h> -#include <linux/irq.h> +#include <linux/interrupt.h> #include <linux/init.h> #include <linux/console.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/serial_core.h> -#include <linux/serial.h> +#include <linux/slab.h> #include <linux/clk.h> #include <linux/platform_device.h> #include <linux/delay.h> #include <linux/of.h> #include <linux/of_device.h> - -#include "msm_serial.h" +#include <linux/wait.h> + +#define UART_MR1 0x0000 + +#define UART_MR1_AUTO_RFR_LEVEL0 0x3F +#define UART_MR1_AUTO_RFR_LEVEL1 0x3FF00 +#define UART_DM_MR1_AUTO_RFR_LEVEL1 0xFFFFFF00 +#define UART_MR1_RX_RDY_CTL BIT(7) +#define UART_MR1_CTS_CTL BIT(6) + +#define UART_MR2 0x0004 +#define UART_MR2_ERROR_MODE BIT(6) +#define UART_MR2_BITS_PER_CHAR 0x30 +#define UART_MR2_BITS_PER_CHAR_5 (0x0 << 4) +#define UART_MR2_BITS_PER_CHAR_6 (0x1 << 4) +#define UART_MR2_BITS_PER_CHAR_7 (0x2 << 4) +#define UART_MR2_BITS_PER_CHAR_8 (0x3 << 4) +#define UART_MR2_STOP_BIT_LEN_ONE (0x1 << 2) +#define UART_MR2_STOP_BIT_LEN_TWO (0x3 << 2) +#define UART_MR2_PARITY_MODE_NONE 0x0 +#define UART_MR2_PARITY_MODE_ODD 0x1 +#define UART_MR2_PARITY_MODE_EVEN 0x2 +#define UART_MR2_PARITY_MODE_SPACE 0x3 +#define UART_MR2_PARITY_MODE 0x3 + +#define UART_CSR 0x0008 + +#define UART_TF 0x000C +#define UARTDM_TF 0x0070 + +#define UART_CR 0x0010 +#define UART_CR_CMD_NULL (0 << 4) +#define UART_CR_CMD_RESET_RX (1 << 4) +#define UART_CR_CMD_RESET_TX (2 << 4) +#define UART_CR_CMD_RESET_ERR (3 << 4) +#define UART_CR_CMD_RESET_BREAK_INT (4 << 4) +#define UART_CR_CMD_START_BREAK (5 << 4) +#define UART_CR_CMD_STOP_BREAK (6 << 4) +#define UART_CR_CMD_RESET_CTS (7 << 4) +#define UART_CR_CMD_RESET_STALE_INT (8 << 4) +#define UART_CR_CMD_PACKET_MODE (9 << 4) +#define UART_CR_CMD_MODE_RESET (12 << 4) +#define UART_CR_CMD_SET_RFR (13 << 4) +#define UART_CR_CMD_RESET_RFR (14 << 4) +#define UART_CR_CMD_PROTECTION_EN (16 << 4) +#define UART_CR_CMD_STALE_EVENT_DISABLE (6 << 8) +#define UART_CR_CMD_STALE_EVENT_ENABLE (80 << 4) +#define UART_CR_CMD_FORCE_STALE (4 << 8) +#define UART_CR_CMD_RESET_TX_READY (3 << 8) +#define UART_CR_TX_DISABLE BIT(3) +#define UART_CR_TX_ENABLE BIT(2) +#define UART_CR_RX_DISABLE BIT(1) +#define UART_CR_RX_ENABLE BIT(0) +#define UART_CR_CMD_RESET_RXBREAK_START ((1 << 11) | (2 << 4)) + +#define UART_IMR 0x0014 +#define UART_IMR_TXLEV BIT(0) +#define UART_IMR_RXSTALE BIT(3) +#define UART_IMR_RXLEV BIT(4) +#define UART_IMR_DELTA_CTS BIT(5) +#define UART_IMR_CURRENT_CTS BIT(6) +#define UART_IMR_RXBREAK_START BIT(10) + +#define UART_IPR_RXSTALE_LAST 0x20 +#define UART_IPR_STALE_LSB 0x1F +#define UART_IPR_STALE_TIMEOUT_MSB 0x3FF80 +#define UART_DM_IPR_STALE_TIMEOUT_MSB 0xFFFFFF80 + +#define UART_IPR 0x0018 +#define UART_TFWR 0x001C +#define UART_RFWR 0x0020 +#define UART_HCR 0x0024 + +#define UART_MREG 0x0028 +#define UART_NREG 0x002C +#define UART_DREG 0x0030 +#define UART_MNDREG 0x0034 +#define UART_IRDA 0x0038 +#define UART_MISR_MODE 0x0040 +#define UART_MISR_RESET 0x0044 +#define UART_MISR_EXPORT 0x0048 +#define UART_MISR_VAL 0x004C +#define UART_TEST_CTRL 0x0050 + +#define UART_SR 0x0008 +#define UART_SR_HUNT_CHAR BIT(7) +#define UART_SR_RX_BREAK BIT(6) +#define UART_SR_PAR_FRAME_ERR BIT(5) +#define UART_SR_OVERRUN BIT(4) +#define UART_SR_TX_EMPTY BIT(3) +#define UART_SR_TX_READY BIT(2) +#define UART_SR_RX_FULL BIT(1) +#define UART_SR_RX_READY BIT(0) + +#define UART_RF 0x000C +#define UARTDM_RF 0x0070 +#define UART_MISR 0x0010 +#define UART_ISR 0x0014 +#define UART_ISR_TX_READY BIT(7) + +#define UARTDM_RXFS 0x50 +#define UARTDM_RXFS_BUF_SHIFT 0x7 +#define UARTDM_RXFS_BUF_MASK 0x7 + +#define UARTDM_DMEN 0x3C +#define UARTDM_DMEN_RX_SC_ENABLE BIT(5) +#define UARTDM_DMEN_TX_SC_ENABLE BIT(4) + +#define UARTDM_DMEN_TX_BAM_ENABLE BIT(2) /* UARTDM_1P4 */ +#define UARTDM_DMEN_TX_DM_ENABLE BIT(0) /* < UARTDM_1P4 */ + +#define UARTDM_DMEN_RX_BAM_ENABLE BIT(3) /* UARTDM_1P4 */ +#define UARTDM_DMEN_RX_DM_ENABLE BIT(1) /* < UARTDM_1P4 */ + +#define UARTDM_DMRX 0x34 +#define UARTDM_NCF_TX 0x40 +#define UARTDM_RX_TOTAL_SNAP 0x38 + +#define UARTDM_BURST_SIZE 16 /* in bytes */ +#define UARTDM_TX_AIGN(x) ((x) & ~0x3) /* valid for > 1p3 */ +#define UARTDM_TX_MAX 256 /* in bytes, valid for <= 1p3 */ +#define UARTDM_RX_SIZE (UART_XMIT_SIZE / 4) enum { UARTDM_1P1 = 1, @@ -46,6 +168,17 @@ enum { UARTDM_1P4, }; +struct msm_dma { + struct dma_chan *chan; + enum dma_data_direction dir; + dma_addr_t phys; + unsigned char *virt; + dma_cookie_t cookie; + u32 enable_bit; + unsigned int count; + struct dma_async_tx_descriptor *desc; +}; + struct msm_port { struct uart_port uart; char name[16]; @@ -55,9 +188,208 @@ struct msm_port { int is_uartdm; unsigned int old_snap_state; bool break_detected; + struct msm_dma tx_dma; + struct msm_dma rx_dma; }; -static inline void wait_for_xmitr(struct uart_port *port) +#define UART_TO_MSM(uart_port) container_of(uart_port, struct msm_port, uart) + +static +void msm_write(struct uart_port *port, unsigned int val, unsigned int off) +{ + writel_relaxed(val, port->membase + off); +} + +static +unsigned int msm_read(struct uart_port *port, unsigned int off) +{ + return readl_relaxed(port->membase + off); +} + +/* + * Setup the MND registers to use the TCXO clock. + */ +static void msm_serial_set_mnd_regs_tcxo(struct uart_port *port) +{ + msm_write(port, 0x06, UART_MREG); + msm_write(port, 0xF1, UART_NREG); + msm_write(port, 0x0F, UART_DREG); + msm_write(port, 0x1A, UART_MNDREG); + port->uartclk = 1843200; +} + +/* + * Setup the MND registers to use the TCXO clock divided by 4. + */ +static void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port) +{ + msm_write(port, 0x18, UART_MREG); + msm_write(port, 0xF6, UART_NREG); + msm_write(port, 0x0F, UART_DREG); + msm_write(port, 0x0A, UART_MNDREG); + port->uartclk = 1843200; +} + +static void msm_serial_set_mnd_regs(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + + /* + * These registers don't exist so we change the clk input rate + * on uartdm hardware instead + */ + if (msm_port->is_uartdm) + return; + + if (port->uartclk == 19200000) + msm_serial_set_mnd_regs_tcxo(port); + else if (port->uartclk == 4800000) + msm_serial_set_mnd_regs_tcxoby4(port); +} + +static void msm_handle_tx(struct uart_port *port); +static void msm_start_rx_dma(struct msm_port *msm_port); + +static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma) +{ + struct device *dev = port->dev; + unsigned int mapped; + u32 val; + + mapped = dma->count; + dma->count = 0; + + dmaengine_terminate_all(dma->chan); + + /* + * DMA Stall happens if enqueue and flush command happens concurrently. + * For example before changing the baud rate/protocol configuration and + * sending flush command to ADM, disable the channel of UARTDM. + * Note: should not reset the receiver here immediately as it is not + * suggested to do disable/reset or reset/disable at the same time. + */ + val = msm_read(port, UARTDM_DMEN); + val &= ~dma->enable_bit; + msm_write(port, val, UARTDM_DMEN); + + if (mapped) + dma_unmap_single(dev, dma->phys, mapped, dma->dir); +} + +static void msm_release_dma(struct msm_port *msm_port) +{ + struct msm_dma *dma; + + dma = &msm_port->tx_dma; + if (dma->chan) { + msm_stop_dma(&msm_port->uart, dma); + dma_release_channel(dma->chan); + } + + memset(dma, 0, sizeof(*dma)); + + dma = &msm_port->rx_dma; + if (dma->chan) { + msm_stop_dma(&msm_port->uart, dma); + dma_release_channel(dma->chan); + kfree(dma->virt); + } + + memset(dma, 0, sizeof(*dma)); +} + +static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base) +{ + struct device *dev = msm_port->uart.dev; + struct dma_slave_config conf; + struct msm_dma *dma; + u32 crci = 0; + int ret; + + dma = &msm_port->tx_dma; + + /* allocate DMA resources, if available */ + dma->chan = dma_request_slave_channel_reason(dev, "tx"); + if (IS_ERR(dma->chan)) + goto no_tx; + + of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci); + + memset(&conf, 0, sizeof(conf)); + conf.direction = DMA_MEM_TO_DEV; + conf.device_fc = true; + conf.dst_addr = base + UARTDM_TF; + conf.dst_maxburst = UARTDM_BURST_SIZE; + conf.slave_id = crci; + + ret = dmaengine_slave_config(dma->chan, &conf); + if (ret) + goto rel_tx; + + dma->dir = DMA_TO_DEVICE; + + if (msm_port->is_uartdm < UARTDM_1P4) + dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE; + else + dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE; + + return; + +rel_tx: + dma_release_channel(dma->chan); +no_tx: + memset(dma, 0, sizeof(*dma)); +} + +static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base) +{ + struct device *dev = msm_port->uart.dev; + struct dma_slave_config conf; + struct msm_dma *dma; + u32 crci = 0; + int ret; + + dma = &msm_port->rx_dma; + + /* allocate DMA resources, if available */ + dma->chan = dma_request_slave_channel_reason(dev, "rx"); + if (IS_ERR(dma->chan)) + goto no_rx; + + of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci); + + dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL); + if (!dma->virt) + goto rel_rx; + + memset(&conf, 0, sizeof(conf)); + conf.direction = DMA_DEV_TO_MEM; + conf.device_fc = true; + conf.src_addr = base + UARTDM_RF; + conf.src_maxburst = UARTDM_BURST_SIZE; + conf.slave_id = crci; + + ret = dmaengine_slave_config(dma->chan, &conf); + if (ret) + goto err; + + dma->dir = DMA_FROM_DEVICE; + + if (msm_port->is_uartdm < UARTDM_1P4) + dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE; + else + dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE; + + return; +err: + kfree(dma->virt); +rel_rx: + dma_release_channel(dma->chan); +no_rx: + memset(dma, 0, sizeof(*dma)); +} + +static inline void msm_wait_for_xmitr(struct uart_port *port) { while (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY)) { if (msm_read(port, UART_ISR) & UART_ISR_TX_READY) @@ -78,17 +410,273 @@ static void msm_stop_tx(struct uart_port *port) static void msm_start_tx(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(port); + struct msm_dma *dma = &msm_port->tx_dma; + /* Already started in DMA mode */ + if (dma->count) + return; + + msm_port->imr |= UART_IMR_TXLEV; + msm_write(port, msm_port->imr, UART_IMR); +} + +static void msm_reset_dm_count(struct uart_port *port, int count) +{ + msm_wait_for_xmitr(port); + msm_write(port, count, UARTDM_NCF_TX); + msm_read(port, UARTDM_NCF_TX); +} + +static void msm_complete_tx_dma(void *args) +{ + struct msm_port *msm_port = args; + struct uart_port *port = &msm_port->uart; + struct circ_buf *xmit = &port->state->xmit; + struct msm_dma *dma = &msm_port->tx_dma; + struct dma_tx_state state; + enum dma_status status; + unsigned long flags; + unsigned int count; + u32 val; + + spin_lock_irqsave(&port->lock, flags); + + /* Already stopped */ + if (!dma->count) + goto done; + + status = dmaengine_tx_status(dma->chan, dma->cookie, &state); + + dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir); + + val = msm_read(port, UARTDM_DMEN); + val &= ~dma->enable_bit; + msm_write(port, val, UARTDM_DMEN); + + if (msm_port->is_uartdm > UARTDM_1P3) { + msm_write(port, UART_CR_CMD_RESET_TX, UART_CR); + msm_write(port, UART_CR_TX_ENABLE, UART_CR); + } + + count = dma->count - state.residue; + port->icount.tx += count; + dma->count = 0; + + xmit->tail += count; + xmit->tail &= UART_XMIT_SIZE - 1; + + /* Restore "Tx FIFO below watermark" interrupt */ msm_port->imr |= UART_IMR_TXLEV; msm_write(port, msm_port->imr, UART_IMR); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + msm_handle_tx(port); +done: + spin_unlock_irqrestore(&port->lock, flags); +} + +static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count) +{ + struct circ_buf *xmit = &msm_port->uart.state->xmit; + struct uart_port *port = &msm_port->uart; + struct msm_dma *dma = &msm_port->tx_dma; + void *cpu_addr; + int ret; + u32 val; + + cpu_addr = &xmit->buf[xmit->tail]; + + dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir); + ret = dma_mapping_error(port->dev, dma->phys); + if (ret) + return ret; + + dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, + count, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | + DMA_PREP_FENCE); + if (!dma->desc) { + ret = -EIO; + goto unmap; + } + + dma->desc->callback = msm_complete_tx_dma; + dma->desc->callback_param = msm_port; + + dma->cookie = dmaengine_submit(dma->desc); + ret = dma_submit_error(dma->cookie); + if (ret) + goto unmap; + + /* + * Using DMA complete for Tx FIFO reload, no need for + * "Tx FIFO below watermark" one, disable it + */ + msm_port->imr &= ~UART_IMR_TXLEV; + msm_write(port, msm_port->imr, UART_IMR); + + dma->count = count; + + val = msm_read(port, UARTDM_DMEN); + val |= dma->enable_bit; + + if (msm_port->is_uartdm < UARTDM_1P4) + msm_write(port, val, UARTDM_DMEN); + + msm_reset_dm_count(port, count); + + if (msm_port->is_uartdm > UARTDM_1P3) + msm_write(port, val, UARTDM_DMEN); + + dma_async_issue_pending(dma->chan); + return 0; +unmap: + dma_unmap_single(port->dev, dma->phys, count, dma->dir); + return ret; +} + +static void msm_complete_rx_dma(void *args) +{ + struct msm_port *msm_port = args; + struct uart_port *port = &msm_port->uart; + struct tty_port *tport = &port->state->port; + struct msm_dma *dma = &msm_port->rx_dma; + int count = 0, i, sysrq; + unsigned long flags; + u32 val; + + spin_lock_irqsave(&port->lock, flags); + + /* Already stopped */ + if (!dma->count) + goto done; + + val = msm_read(port, UARTDM_DMEN); + val &= ~dma->enable_bit; + msm_write(port, val, UARTDM_DMEN); + + if (msm_read(port, UART_SR) & UART_SR_OVERRUN) { + port->icount.overrun++; + tty_insert_flip_char(tport, 0, TTY_OVERRUN); + msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR); + } + + count = msm_read(port, UARTDM_RX_TOTAL_SNAP); + + port->icount.rx += count; + + dma->count = 0; + + dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); + + for (i = 0; i < count; i++) { + char flag = TTY_NORMAL; + + if (msm_port->break_detected && dma->virt[i] == 0) { + port->icount.brk++; + flag = TTY_BREAK; + msm_port->break_detected = false; + if (uart_handle_break(port)) + continue; + } + + if (!(port->read_status_mask & UART_SR_RX_BREAK)) + flag = TTY_NORMAL; + + spin_unlock_irqrestore(&port->lock, flags); + sysrq = uart_handle_sysrq_char(port, dma->virt[i]); + spin_lock_irqsave(&port->lock, flags); + if (!sysrq) + tty_insert_flip_char(tport, dma->virt[i], flag); + } + + msm_start_rx_dma(msm_port); +done: + spin_unlock_irqrestore(&port->lock, flags); + + if (count) + tty_flip_buffer_push(tport); +} + +static void msm_start_rx_dma(struct msm_port *msm_port) +{ + struct msm_dma *dma = &msm_port->rx_dma; + struct uart_port *uart = &msm_port->uart; + u32 val; + int ret; + + if (!dma->chan) + return; + + dma->phys = dma_map_single(uart->dev, dma->virt, + UARTDM_RX_SIZE, dma->dir); + ret = dma_mapping_error(uart->dev, dma->phys); + if (ret) + return; + + dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, + UARTDM_RX_SIZE, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT); + if (!dma->desc) + goto unmap; + + dma->desc->callback = msm_complete_rx_dma; + dma->desc->callback_param = msm_port; + + dma->cookie = dmaengine_submit(dma->desc); + ret = dma_submit_error(dma->cookie); + if (ret) + goto unmap; + /* + * Using DMA for FIFO off-load, no need for "Rx FIFO over + * watermark" or "stale" interrupts, disable them + */ + msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE); + + /* + * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3), + * we need RXSTALE to flush input DMA fifo to memory + */ + if (msm_port->is_uartdm < UARTDM_1P4) + msm_port->imr |= UART_IMR_RXSTALE; + + msm_write(uart, msm_port->imr, UART_IMR); + + dma->count = UARTDM_RX_SIZE; + + dma_async_issue_pending(dma->chan); + + msm_write(uart, UART_CR_CMD_RESET_STALE_INT, UART_CR); + msm_write(uart, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR); + + val = msm_read(uart, UARTDM_DMEN); + val |= dma->enable_bit; + + if (msm_port->is_uartdm < UARTDM_1P4) + msm_write(uart, val, UARTDM_DMEN); + + msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX); + + if (msm_port->is_uartdm > UARTDM_1P3) + msm_write(uart, val, UARTDM_DMEN); + + return; +unmap: + dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); } static void msm_stop_rx(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(port); + struct msm_dma *dma = &msm_port->rx_dma; msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE); msm_write(port, msm_port->imr, UART_IMR); + + if (dma->chan) + msm_stop_dma(port, dma); } static void msm_enable_ms(struct uart_port *port) @@ -99,7 +687,7 @@ static void msm_enable_ms(struct uart_port *port) msm_write(port, msm_port->imr, UART_IMR); } -static void handle_rx_dm(struct uart_port *port, unsigned int misr) +static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr) { struct tty_port *tport = &port->state->port; unsigned int sr; @@ -169,9 +757,12 @@ static void handle_rx_dm(struct uart_port *port, unsigned int misr) msm_write(port, UART_CR_CMD_RESET_STALE_INT, UART_CR); msm_write(port, 0xFFFFFF, UARTDM_DMRX); msm_write(port, UART_CR_CMD_STALE_EVENT_ENABLE, UART_CR); + + /* Try to use DMA */ + msm_start_rx_dma(msm_port); } -static void handle_rx(struct uart_port *port) +static void msm_handle_rx(struct uart_port *port) { struct tty_port *tport = &port->state->port; unsigned int sr; @@ -224,18 +815,11 @@ static void handle_rx(struct uart_port *port) spin_lock(&port->lock); } -static void reset_dm_count(struct uart_port *port, int count) -{ - wait_for_xmitr(port); - msm_write(port, count, UARTDM_NCF_TX); - msm_read(port, UARTDM_NCF_TX); -} - -static void handle_tx(struct uart_port *port) +static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count) { struct circ_buf *xmit = &port->state->xmit; struct msm_port *msm_port = UART_TO_MSM(port); - unsigned int tx_count, num_chars; + unsigned int num_chars; unsigned int tf_pointer = 0; void __iomem *tf; @@ -244,20 +828,8 @@ static void handle_tx(struct uart_port *port) else tf = port->membase + UART_TF; - tx_count = uart_circ_chars_pending(xmit); - tx_count = min3(tx_count, (unsigned int)UART_XMIT_SIZE - xmit->tail, - port->fifosize); - - if (port->x_char) { - if (msm_port->is_uartdm) - reset_dm_count(port, tx_count + 1); - - iowrite8_rep(tf, &port->x_char, 1); - port->icount.tx++; - port->x_char = 0; - } else if (tx_count && msm_port->is_uartdm) { - reset_dm_count(port, tx_count); - } + if (tx_count && msm_port->is_uartdm) + msm_reset_dm_count(port, tx_count); while (tf_pointer < tx_count) { int i; @@ -290,20 +862,76 @@ static void handle_tx(struct uart_port *port) uart_write_wakeup(port); } -static void handle_delta_cts(struct uart_port *port) +static void msm_handle_tx(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + struct circ_buf *xmit = &msm_port->uart.state->xmit; + struct msm_dma *dma = &msm_port->tx_dma; + unsigned int pio_count, dma_count, dma_min; + void __iomem *tf; + int err = 0; + + if (port->x_char) { + if (msm_port->is_uartdm) + tf = port->membase + UARTDM_TF; + else + tf = port->membase + UART_TF; + + if (msm_port->is_uartdm) + msm_reset_dm_count(port, 1); + + iowrite8_rep(tf, &port->x_char, 1); + port->icount.tx++; + port->x_char = 0; + return; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + msm_stop_tx(port); + return; + } + + pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + + dma_min = 1; /* Always DMA */ + if (msm_port->is_uartdm > UARTDM_1P3) { + dma_count = UARTDM_TX_AIGN(dma_count); + dma_min = UARTDM_BURST_SIZE; + } else { + if (dma_count > UARTDM_TX_MAX) + dma_count = UARTDM_TX_MAX; + } + + if (pio_count > port->fifosize) + pio_count = port->fifosize; + + if (!dma->chan || dma_count < dma_min) + msm_handle_tx_pio(port, pio_count); + else + err = msm_handle_tx_dma(msm_port, dma_count); + + if (err) /* fall back to PIO mode */ + msm_handle_tx_pio(port, pio_count); +} + +static void msm_handle_delta_cts(struct uart_port *port) { msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR); port->icount.cts++; wake_up_interruptible(&port->state->port.delta_msr_wait); } -static irqreturn_t msm_irq(int irq, void *dev_id) +static irqreturn_t msm_uart_irq(int irq, void *dev_id) { struct uart_port *port = dev_id; struct msm_port *msm_port = UART_TO_MSM(port); + struct msm_dma *dma = &msm_port->rx_dma; + unsigned long flags; unsigned int misr; + u32 val; - spin_lock(&port->lock); + spin_lock_irqsave(&port->lock, flags); misr = msm_read(port, UART_MISR); msm_write(port, 0, UART_IMR); /* disable interrupt */ @@ -313,18 +941,29 @@ static irqreturn_t msm_irq(int irq, void *dev_id) } if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) { - if (msm_port->is_uartdm) - handle_rx_dm(port, misr); - else - handle_rx(port); + if (dma->count) { + val = UART_CR_CMD_STALE_EVENT_DISABLE; + msm_write(port, val, UART_CR); + val = UART_CR_CMD_RESET_STALE_INT; + msm_write(port, val, UART_CR); + /* + * Flush DMA input fifo to memory, this will also + * trigger DMA RX completion + */ + dmaengine_terminate_all(dma->chan); + } else if (msm_port->is_uartdm) { + msm_handle_rx_dm(port, misr); + } else { + msm_handle_rx(port); + } } if (misr & UART_IMR_TXLEV) - handle_tx(port); + msm_handle_tx(port); if (misr & UART_IMR_DELTA_CTS) - handle_delta_cts(port); + msm_handle_delta_cts(port); msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */ - spin_unlock(&port->lock); + spin_unlock_irqrestore(&port->lock, flags); return IRQ_HANDLED; } @@ -387,53 +1026,107 @@ struct msm_baud_map { }; static const struct msm_baud_map * -msm_find_best_baud(struct uart_port *port, unsigned int baud) +msm_find_best_baud(struct uart_port *port, unsigned int baud, + unsigned long *rate) { - unsigned int i, divisor; - const struct msm_baud_map *entry; + struct msm_port *msm_port = UART_TO_MSM(port); + unsigned int divisor, result; + unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX; + const struct msm_baud_map *entry, *end, *best; static const struct msm_baud_map table[] = { - { 1536, 0x00, 1 }, - { 768, 0x11, 1 }, - { 384, 0x22, 1 }, - { 192, 0x33, 1 }, - { 96, 0x44, 1 }, - { 48, 0x55, 1 }, - { 32, 0x66, 1 }, - { 24, 0x77, 1 }, - { 16, 0x88, 1 }, - { 12, 0x99, 6 }, - { 8, 0xaa, 6 }, - { 6, 0xbb, 6 }, - { 4, 0xcc, 6 }, - { 3, 0xdd, 8 }, - { 2, 0xee, 16 }, { 1, 0xff, 31 }, + { 2, 0xee, 16 }, + { 3, 0xdd, 8 }, + { 4, 0xcc, 6 }, + { 6, 0xbb, 6 }, + { 8, 0xaa, 6 }, + { 12, 0x99, 6 }, + { 16, 0x88, 1 }, + { 24, 0x77, 1 }, + { 32, 0x66, 1 }, + { 48, 0x55, 1 }, + { 96, 0x44, 1 }, + { 192, 0x33, 1 }, + { 384, 0x22, 1 }, + { 768, 0x11, 1 }, + { 1536, 0x00, 1 }, }; - divisor = uart_get_divisor(port, baud); + best = table; /* Default to smallest divider */ + target = clk_round_rate(msm_port->clk, 16 * baud); + divisor = DIV_ROUND_CLOSEST(target, 16 * baud); + + end = table + ARRAY_SIZE(table); + entry = table; + while (entry < end) { + if (entry->divisor <= divisor) { + result = target / entry->divisor / 16; + diff = abs(result - baud); + + /* Keep track of best entry */ + if (diff < best_diff) { + best_diff = diff; + best = entry; + best_rate = target; + } - for (i = 0, entry = table; i < ARRAY_SIZE(table); i++, entry++) - if (entry->divisor <= divisor) - break; + if (result == baud) + break; + } else if (entry->divisor > divisor) { + old = target; + target = clk_round_rate(msm_port->clk, old + 1); + /* + * The rate didn't get any faster so we can't do + * better at dividing it down + */ + if (target == old) + break; + + /* Start the divisor search over at this new rate */ + entry = table; + divisor = DIV_ROUND_CLOSEST(target, 16 * baud); + continue; + } + entry++; + } - return entry; /* Default to smallest divider */ + *rate = best_rate; + return best; } -static int msm_set_baud_rate(struct uart_port *port, unsigned int baud) +static int msm_set_baud_rate(struct uart_port *port, unsigned int baud, + unsigned long *saved_flags) { - unsigned int rxstale, watermark; + unsigned int rxstale, watermark, mask; struct msm_port *msm_port = UART_TO_MSM(port); const struct msm_baud_map *entry; + unsigned long flags, rate; - entry = msm_find_best_baud(port, baud); + flags = *saved_flags; + spin_unlock_irqrestore(&port->lock, flags); + + entry = msm_find_best_baud(port, baud, &rate); + clk_set_rate(msm_port->clk, rate); + baud = rate / 16 / entry->divisor; + + spin_lock_irqsave(&port->lock, flags); + *saved_flags = flags; + port->uartclk = rate; msm_write(port, entry->code, UART_CSR); /* RX stale watermark */ rxstale = entry->rxstale; watermark = UART_IPR_STALE_LSB & rxstale; - watermark |= UART_IPR_RXSTALE_LAST; - watermark |= UART_IPR_STALE_TIMEOUT_MSB & (rxstale << 2); + if (msm_port->is_uartdm) { + mask = UART_DM_IPR_STALE_TIMEOUT_MSB; + } else { + watermark |= UART_IPR_RXSTALE_LAST; + mask = UART_IPR_STALE_TIMEOUT_MSB; + } + + watermark |= mask & (rxstale << 2); + msm_write(port, watermark, UART_IPR); /* set RX watermark */ @@ -476,13 +1169,13 @@ static void msm_init_clock(struct uart_port *port) static int msm_startup(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(port); - unsigned int data, rfr_level; + unsigned int data, rfr_level, mask; int ret; snprintf(msm_port->name, sizeof(msm_port->name), "msm_serial%d", port->line); - ret = request_irq(port->irq, msm_irq, IRQF_TRIGGER_HIGH, + ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH, msm_port->name, port); if (unlikely(ret)) return ret; @@ -496,11 +1189,23 @@ static int msm_startup(struct uart_port *port) /* set automatic RFR level */ data = msm_read(port, UART_MR1); - data &= ~UART_MR1_AUTO_RFR_LEVEL1; + + if (msm_port->is_uartdm) + mask = UART_DM_MR1_AUTO_RFR_LEVEL1; + else + mask = UART_MR1_AUTO_RFR_LEVEL1; + + data &= ~mask; data &= ~UART_MR1_AUTO_RFR_LEVEL0; - data |= UART_MR1_AUTO_RFR_LEVEL1 & (rfr_level << 2); + data |= mask & (rfr_level << 2); data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level; msm_write(port, data, UART_MR1); + + if (msm_port->is_uartdm) { + msm_request_tx_dma(msm_port, msm_port->uart.mapbase); + msm_request_rx_dma(msm_port, msm_port->uart.mapbase); + } + return 0; } @@ -511,6 +1216,9 @@ static void msm_shutdown(struct uart_port *port) msm_port->imr = 0; msm_write(port, 0, UART_IMR); /* disable interrupts */ + if (msm_port->is_uartdm) + msm_release_dma(msm_port); + clk_disable_unprepare(msm_port->clk); free_irq(port->irq, port); @@ -519,14 +1227,19 @@ static void msm_shutdown(struct uart_port *port) static void msm_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { + struct msm_port *msm_port = UART_TO_MSM(port); + struct msm_dma *dma = &msm_port->rx_dma; unsigned long flags; unsigned int baud, mr; spin_lock_irqsave(&port->lock, flags); + if (dma->chan) /* Terminate if any */ + msm_stop_dma(port, dma); + /* calculate and set baud rate */ - baud = uart_get_baud_rate(port, termios, old, 300, 115200); - baud = msm_set_baud_rate(port, baud); + baud = uart_get_baud_rate(port, termios, old, 300, 4000000); + baud = msm_set_baud_rate(port, baud, &flags); if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); @@ -588,6 +1301,9 @@ static void msm_set_termios(struct uart_port *port, struct ktermios *termios, uart_update_timeout(port, termios->c_cflag, baud); + /* Try to use DMA */ + msm_start_rx_dma(msm_port); + spin_unlock_irqrestore(&port->lock, flags); } @@ -765,7 +1481,7 @@ static void msm_poll_put_char(struct uart_port *port, unsigned char c) msm_write(port, 0, UART_IMR); if (msm_port->is_uartdm) - reset_dm_count(port, 1); + msm_reset_dm_count(port, 1); /* Wait until FIFO is empty */ while (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) @@ -839,7 +1555,7 @@ static struct msm_port msm_uart_ports[] = { #define UART_NR ARRAY_SIZE(msm_uart_ports) -static inline struct uart_port *get_port_from_line(unsigned int line) +static inline struct uart_port *msm_get_port_from_line(unsigned int line) { return &msm_uart_ports[line].uart; } @@ -866,7 +1582,7 @@ static void __msm_console_write(struct uart_port *port, const char *s, spin_lock(&port->lock); if (is_uartdm) - reset_dm_count(port, count); + msm_reset_dm_count(port, count); i = 0; while (i < count) { @@ -911,7 +1627,7 @@ static void msm_console_write(struct console *co, const char *s, BUG_ON(co->index < 0 || co->index >= UART_NR); - port = get_port_from_line(co->index); + port = msm_get_port_from_line(co->index); msm_port = UART_TO_MSM(port); __msm_console_write(port, s, count, msm_port->is_uartdm); @@ -928,7 +1644,7 @@ static int __init msm_console_setup(struct console *co, char *options) if (unlikely(co->index >= UART_NR || co->index < 0)) return -ENXIO; - port = get_port_from_line(co->index); + port = msm_get_port_from_line(co->index); if (unlikely(!port->membase)) return -ENXIO; @@ -960,7 +1676,6 @@ msm_serial_early_console_setup(struct earlycon_device *device, const char *opt) device->con->write = msm_serial_early_write; return 0; } -EARLYCON_DECLARE(msm_serial, msm_serial_early_console_setup); OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart", msm_serial_early_console_setup); @@ -982,7 +1697,6 @@ msm_serial_early_console_setup_dm(struct earlycon_device *device, device->con->write = msm_serial_early_write_dm; return 0; } -EARLYCON_DECLARE(msm_serial_dm, msm_serial_early_console_setup_dm); OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm", msm_serial_early_console_setup_dm); @@ -1043,7 +1757,7 @@ static int msm_serial_probe(struct platform_device *pdev) dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line); - port = get_port_from_line(line); + port = msm_get_port_from_line(line); port->dev = &pdev->dev; msm_port = UART_TO_MSM(port); @@ -1061,8 +1775,6 @@ static int msm_serial_probe(struct platform_device *pdev) msm_port->pclk = devm_clk_get(&pdev->dev, "iface"); if (IS_ERR(msm_port->pclk)) return PTR_ERR(msm_port->pclk); - - clk_set_rate(msm_port->clk, 1843200); } port->uartclk = clk_get_rate(msm_port->clk); |