/* * Driver for msm7k serial device and console * * Copyright (C) 2007 Google, Inc. * Author: Robert Love <rlove@google.com> * Copyright (c) 2011, Code Aurora Forum. All rights reserved. * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) # define SUPPORT_SYSRQ #endif #include <linux/atomic.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/hrtimer.h> #include <linux/module.h> #include <linux/io.h> #include <linux/ioport.h> #include <linux/irq.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" #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, UARTDM_1P2, UARTDM_1P3, 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]; struct clk *clk; struct clk *pclk; unsigned int imr; int is_uartdm; unsigned int old_snap_state; bool break_detected; struct msm_dma tx_dma; struct msm_dma rx_dma; }; static void msm_handle_tx(struct uart_port *port); static void msm_start_rx_dma(struct msm_port *msm_port); 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) break; udelay(1); } msm_write(port, UART_CR_CMD_RESET_TX_READY, UART_CR); } static void msm_stop_tx(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(port); msm_port->imr &= ~UART_IMR_TXLEV; msm_write(port, msm_port->imr, UART_IMR); } 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); /* Restore interrupts */ msm_port->imr |= UART_IMR_RXLEV | UART_IMR_RXSTALE; msm_write(port, msm_port->imr, UART_IMR); 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) { struct msm_port *msm_port = UART_TO_MSM(port); msm_port->imr |= UART_IMR_DELTA_CTS; msm_write(port, msm_port->imr, UART_IMR); } static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr) { struct tty_port *tport = &port->state->port; unsigned int sr; int count = 0; struct msm_port *msm_port = UART_TO_MSM(port); 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); } if (misr & UART_IMR_RXSTALE) { count = msm_read(port, UARTDM_RX_TOTAL_SNAP) - msm_port->old_snap_state; msm_port->old_snap_state = 0; } else { count = 4 * (msm_read(port, UART_RFWR)); msm_port->old_snap_state += count; } /* TODO: Precise error reporting */ port->icount.rx += count; while (count > 0) { unsigned char buf[4]; int sysrq, r_count, i; sr = msm_read(port, UART_SR); if ((sr & UART_SR_RX_READY) == 0) { msm_port->old_snap_state -= count; break; } ioread32_rep(port->membase + UARTDM_RF, buf, 1); r_count = min_t(int, count, sizeof(buf)); for (i = 0; i < r_count; i++) { char flag = TTY_NORMAL; if (msm_port->break_detected && buf[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(&port->lock); sysrq = uart_handle_sysrq_char(port, buf[i]); spin_lock(&port->lock); if (!sysrq) tty_insert_flip_char(tport, buf[i], flag); } count -= r_count; } spin_unlock(&port->lock); tty_flip_buffer_push(tport); spin_lock(&port->lock); if (misr & (UART_IMR_RXSTALE)) 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 msm_handle_rx(struct uart_port *port) { struct tty_port *tport = &port->state->port; unsigned int sr; /* * Handle overrun. My understanding of the hardware is that overrun * is not tied to the RX buffer, so we handle the case out of band. */ 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); } /* and now the main RX loop */ while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) { unsigned int c; char flag = TTY_NORMAL; int sysrq; c = msm_read(port, UART_RF); if (sr & UART_SR_RX_BREAK) { port->icount.brk++; if (uart_handle_break(port)) continue; } else if (sr & UART_SR_PAR_FRAME_ERR) { port->icount.frame++; } else { port->icount.rx++; } /* Mask conditions we're ignorning. */ sr &= port->read_status_mask; if (sr & UART_SR_RX_BREAK) flag = TTY_BREAK; else if (sr & UART_SR_PAR_FRAME_ERR) flag = TTY_FRAME; spin_unlock(&port->lock); sysrq = uart_handle_sysrq_char(port, c); spin_lock(&port->lock); if (!sysrq) tty_insert_flip_char(tport, c, flag); } spin_unlock(&port->lock); tty_flip_buffer_push(tport); spin_lock(&port->lock); } 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 num_chars; unsigned int tf_pointer = 0; void __iomem *tf; if (msm_port->is_uartdm) tf = port->membase + UARTDM_TF; else tf = port->membase + UART_TF; if (tx_count && msm_port->is_uartdm) msm_reset_dm_count(port, tx_count); while (tf_pointer < tx_count) { int i; char buf[4] = { 0 }; if (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) break; if (msm_port->is_uartdm) num_chars = min(tx_count - tf_pointer, (unsigned int)sizeof(buf)); else num_chars = 1; for (i = 0; i < num_chars; i++) { buf[i] = xmit->buf[xmit->tail + i]; port->icount.tx++; } iowrite32_rep(tf, buf, 1); xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1); tf_pointer += num_chars; } /* disable tx interrupts if nothing more to send */ if (uart_circ_empty(xmit)) msm_stop_tx(port); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(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(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_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_irqsave(&port->lock, flags); misr = msm_read(port, UART_MISR); msm_write(port, 0, UART_IMR); /* disable interrupt */ if (misr & UART_IMR_RXBREAK_START) { msm_port->break_detected = true; msm_write(port, UART_CR_CMD_RESET_RXBREAK_START, UART_CR); } if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) { 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) msm_handle_tx(port); if (misr & UART_IMR_DELTA_CTS) msm_handle_delta_cts(port); msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */ spin_unlock_irqrestore(&port->lock, flags); return IRQ_HANDLED; } static unsigned int msm_tx_empty(struct uart_port *port) { return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0; } static unsigned int msm_get_mctrl(struct uart_port *port) { return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS; } static void msm_reset(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(port); /* reset everything */ msm_write(port, UART_CR_CMD_RESET_RX, UART_CR); msm_write(port, UART_CR_CMD_RESET_TX, UART_CR); msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR); msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR); msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR); msm_write(port, UART_CR_CMD_SET_RFR, UART_CR); /* Disable DM modes */ if (msm_port->is_uartdm) msm_write(port, 0, UARTDM_DMEN); } static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl) { unsigned int mr; mr = msm_read(port, UART_MR1); if (!(mctrl & TIOCM_RTS)) { mr &= ~UART_MR1_RX_RDY_CTL; msm_write(port, mr, UART_MR1); msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR); } else { mr |= UART_MR1_RX_RDY_CTL; msm_write(port, mr, UART_MR1); } } static void msm_break_ctl(struct uart_port *port, int break_ctl) { if (break_ctl) msm_write(port, UART_CR_CMD_START_BREAK, UART_CR); else msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR); } struct msm_baud_map { u16 divisor; u8 code; u8 rxstale; }; static const struct msm_baud_map * msm_find_best_baud(struct uart_port *port, unsigned int baud) { unsigned int i, divisor; const struct msm_baud_map *entry; 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 }, { 0, 0xff, 31 }, }; divisor = uart_get_divisor(port, baud); for (i = 0, entry = table; i < ARRAY_SIZE(table); i++, entry++) if (entry->divisor <= divisor) break; return entry; /* Default to smallest divider */ } static int msm_set_baud_rate(struct uart_port *port, unsigned int baud, unsigned long *saved_flags) { unsigned int rxstale, watermark, mask; struct msm_port *msm_port = UART_TO_MSM(port); const struct msm_baud_map *entry; unsigned long flags; entry = msm_find_best_baud(port, baud); msm_write(port, entry->code, UART_CSR); if (baud > 460800) port->uartclk = baud * 16; flags = *saved_flags; spin_unlock_irqrestore(&port->lock, flags); clk_set_rate(msm_port->clk, port->uartclk); spin_lock_irqsave(&port->lock, flags); *saved_flags = flags; /* RX stale watermark */ rxstale = entry->rxstale; watermark = UART_IPR_STALE_LSB & rxstale; 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 */ watermark = (port->fifosize * 3) / 4; msm_write(port, watermark, UART_RFWR); /* set TX watermark */ msm_write(port, 10, UART_TFWR); msm_write(port, UART_CR_CMD_PROTECTION_EN, UART_CR); msm_reset(port); /* Enable RX and TX */ msm_write(port, UART_CR_TX_ENABLE | UART_CR_RX_ENABLE, UART_CR); /* turn on RX and CTS interrupts */ msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE | UART_IMR_CURRENT_CTS | UART_IMR_RXBREAK_START; msm_write(port, msm_port->imr, UART_IMR); if (msm_port->is_uartdm) { 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); } return baud; } static void msm_init_clock(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(port); clk_prepare_enable(msm_port->clk); clk_prepare_enable(msm_port->pclk); msm_serial_set_mnd_regs(port); } static int msm_startup(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(port); 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_uart_irq, IRQF_TRIGGER_HIGH, msm_port->name, port); if (unlikely(ret)) return ret; msm_init_clock(port); if (likely(port->fifosize > 12)) rfr_level = port->fifosize - 12; else rfr_level = port->fifosize; /* set automatic RFR level */ data = msm_read(port, UART_MR1); 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 |= 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; } static void msm_shutdown(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(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); } 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, 4000000); baud = msm_set_baud_rate(port, baud, &flags); if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); /* calculate parity */ mr = msm_read(port, UART_MR2); mr &= ~UART_MR2_PARITY_MODE; if (termios->c_cflag & PARENB) { if (termios->c_cflag & PARODD) mr |= UART_MR2_PARITY_MODE_ODD; else if (termios->c_cflag & CMSPAR) mr |= UART_MR2_PARITY_MODE_SPACE; else mr |= UART_MR2_PARITY_MODE_EVEN; } /* calculate bits per char */ mr &= ~UART_MR2_BITS_PER_CHAR; switch (termios->c_cflag & CSIZE) { case CS5: mr |= UART_MR2_BITS_PER_CHAR_5; break; case CS6: mr |= UART_MR2_BITS_PER_CHAR_6; break; case CS7: mr |= UART_MR2_BITS_PER_CHAR_7; break; case CS8: default: mr |= UART_MR2_BITS_PER_CHAR_8; break; } /* calculate stop bits */ mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO); if (termios->c_cflag & CSTOPB) mr |= UART_MR2_STOP_BIT_LEN_TWO; else mr |= UART_MR2_STOP_BIT_LEN_ONE; /* set parity, bits per char, and stop bit */ msm_write(port, mr, UART_MR2); /* calculate and set hardware flow control */ mr = msm_read(port, UART_MR1); mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL); if (termios->c_cflag & CRTSCTS) { mr |= UART_MR1_CTS_CTL; mr |= UART_MR1_RX_RDY_CTL; } msm_write(port, mr, UART_MR1); /* Configure status bits to ignore based on termio flags. */ port->read_status_mask = 0; if (termios->c_iflag & INPCK) port->read_status_mask |= UART_SR_PAR_FRAME_ERR; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) port->read_status_mask |= UART_SR_RX_BREAK; uart_update_timeout(port, termios->c_cflag, baud); /* Try to use DMA */ msm_start_rx_dma(msm_port); spin_unlock_irqrestore(&port->lock, flags); } static const char *msm_type(struct uart_port *port) { return "MSM"; } static void msm_release_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *uart_resource; resource_size_t size; uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (unlikely(!uart_resource)) return; size = resource_size(uart_resource); release_mem_region(port->mapbase, size); iounmap(port->membase); port->membase = NULL; } static int msm_request_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *uart_resource; resource_size_t size; int ret; uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (unlikely(!uart_resource)) return -ENXIO; size = resource_size(uart_resource); if (!request_mem_region(port->mapbase, size, "msm_serial")) return -EBUSY; port->membase = ioremap(port->mapbase, size); if (!port->membase) { ret = -EBUSY; goto fail_release_port; } return 0; fail_release_port: release_mem_region(port->mapbase, size); return ret; } static void msm_config_port(struct uart_port *port, int flags) { int ret; if (flags & UART_CONFIG_TYPE) { port->type = PORT_MSM; ret = msm_request_port(port); if (ret) return; } } static int msm_verify_port(struct uart_port *port, struct serial_struct *ser) { if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM)) return -EINVAL; if (unlikely(port->irq != ser->irq)) return -EINVAL; return 0; } static void msm_power(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct msm_port *msm_port = UART_TO_MSM(port); switch (state) { case 0: clk_prepare_enable(msm_port->clk); clk_prepare_enable(msm_port->pclk); break; case 3: clk_disable_unprepare(msm_port->clk); clk_disable_unprepare(msm_port->pclk); break; default: pr_err("msm_serial: Unknown PM state %d\n", state); } } #ifdef CONFIG_CONSOLE_POLL static int msm_poll_get_char_single(struct uart_port *port) { struct msm_port *msm_port = UART_TO_MSM(port); unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : UART_RF; if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) return NO_POLL_CHAR; return msm_read(port, rf_reg) & 0xff; } static int msm_poll_get_char_dm(struct uart_port *port) { int c; static u32 slop; static int count; unsigned char *sp = (unsigned char *)&slop; /* Check if a previous read had more than one char */ if (count) { c = sp[sizeof(slop) - count]; count--; /* Or if FIFO is empty */ } else if (!(msm_read(port, UART_SR) & UART_SR_RX_READY)) { /* * If RX packing buffer has less than a word, force stale to * push contents into RX FIFO */ count = msm_read(port, UARTDM_RXFS); count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK; if (count) { msm_write(port, UART_CR_CMD_FORCE_STALE, UART_CR); slop = msm_read(port, UARTDM_RF); c = sp[0]; count--; 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); } else { c = NO_POLL_CHAR; } /* FIFO has a word */ } else { slop = msm_read(port, UARTDM_RF); c = sp[0]; count = sizeof(slop) - 1; } return c; } static int msm_poll_get_char(struct uart_port *port) { u32 imr; int c; struct msm_port *msm_port = UART_TO_MSM(port); /* Disable all interrupts */ imr = msm_read(port, UART_IMR); msm_write(port, 0, UART_IMR); if (msm_port->is_uartdm) c = msm_poll_get_char_dm(port); else c = msm_poll_get_char_single(port); /* Enable interrupts */ msm_write(port, imr, UART_IMR); return c; } static void msm_poll_put_char(struct uart_port *port, unsigned char c) { u32 imr; struct msm_port *msm_port = UART_TO_MSM(port); /* Disable all interrupts */ imr = msm_read(port, UART_IMR); msm_write(port, 0, UART_IMR); if (msm_port->is_uartdm) msm_reset_dm_count(port, 1); /* Wait until FIFO is empty */ while (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) cpu_relax(); /* Write a character */ msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : UART_TF); /* Wait until FIFO is empty */ while (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) cpu_relax(); /* Enable interrupts */ msm_write(port, imr, UART_IMR); } #endif static struct uart_ops msm_uart_pops = { .tx_empty = msm_tx_empty, .set_mctrl = msm_set_mctrl, .get_mctrl = msm_get_mctrl, .stop_tx = msm_stop_tx, .start_tx = msm_start_tx, .stop_rx = msm_stop_rx, .enable_ms = msm_enable_ms, .break_ctl = msm_break_ctl, .startup = msm_startup, .shutdown = msm_shutdown, .set_termios = msm_set_termios, .type = msm_type, .release_port = msm_release_port, .request_port = msm_request_port, .config_port = msm_config_port, .verify_port = msm_verify_port, .pm = msm_power, #ifdef CONFIG_CONSOLE_POLL .poll_get_char = msm_poll_get_char, .poll_put_char = msm_poll_put_char, #endif }; static struct msm_port msm_uart_ports[] = { { .uart = { .iotype = UPIO_MEM, .ops = &msm_uart_pops, .flags = UPF_BOOT_AUTOCONF, .fifosize = 64, .line = 0, }, }, { .uart = { .iotype = UPIO_MEM, .ops = &msm_uart_pops, .flags = UPF_BOOT_AUTOCONF, .fifosize = 64, .line = 1, }, }, { .uart = { .iotype = UPIO_MEM, .ops = &msm_uart_pops, .flags = UPF_BOOT_AUTOCONF, .fifosize = 64, .line = 2, }, }, }; #define UART_NR ARRAY_SIZE(msm_uart_ports) static inline struct uart_port *msm_get_port_from_line(unsigned int line) { return &msm_uart_ports[line].uart; } #ifdef CONFIG_SERIAL_MSM_CONSOLE static void __msm_console_write(struct uart_port *port, const char *s, unsigned int count, bool is_uartdm) { int i; int num_newlines = 0; bool replaced = false; void __iomem *tf; if (is_uartdm) tf = port->membase + UARTDM_TF; else tf = port->membase + UART_TF; /* Account for newlines that will get a carriage return added */ for (i = 0; i < count; i++) if (s[i] == '\n') num_newlines++; count += num_newlines; spin_lock(&port->lock); if (is_uartdm) msm_reset_dm_count(port, count); i = 0; while (i < count) { int j; unsigned int num_chars; char buf[4] = { 0 }; if (is_uartdm) num_chars = min(count - i, (unsigned int)sizeof(buf)); else num_chars = 1; for (j = 0; j < num_chars; j++) { char c = *s; if (c == '\n' && !replaced) { buf[j] = '\r'; j++; replaced = true; } if (j < num_chars) { buf[j] = c; s++; replaced = false; } } while (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) cpu_relax(); iowrite32_rep(tf, buf, 1); i += num_chars; } spin_unlock(&port->lock); } static void msm_console_write(struct console *co, const char *s, unsigned int count) { struct uart_port *port; struct msm_port *msm_port; BUG_ON(co->index < 0 || co->index >= UART_NR); port = msm_get_port_from_line(co->index); msm_port = UART_TO_MSM(port); __msm_console_write(port, s, count, msm_port->is_uartdm); } static int __init msm_console_setup(struct console *co, char *options) { struct uart_port *port; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; if (unlikely(co->index >= UART_NR || co->index < 0)) return -ENXIO; port = msm_get_port_from_line(co->index); if (unlikely(!port->membase)) return -ENXIO; msm_init_clock(port); if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); pr_info("msm_serial: console setup on port #%d\n", port->line); return uart_set_options(port, co, baud, parity, bits, flow); } static void msm_serial_early_write(struct console *con, const char *s, unsigned n) { struct earlycon_device *dev = con->data; __msm_console_write(&dev->port, s, n, false); } static int __init msm_serial_early_console_setup(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; 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); static void msm_serial_early_write_dm(struct console *con, const char *s, unsigned n) { struct earlycon_device *dev = con->data; __msm_console_write(&dev->port, s, n, true); } static int __init msm_serial_early_console_setup_dm(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; 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); static struct uart_driver msm_uart_driver; static struct console msm_console = { .name = "ttyMSM", .write = msm_console_write, .device = uart_console_device, .setup = msm_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &msm_uart_driver, }; #define MSM_CONSOLE (&msm_console) #else #define MSM_CONSOLE NULL #endif static struct uart_driver msm_uart_driver = { .owner = THIS_MODULE, .driver_name = "msm_serial", .dev_name = "ttyMSM", .nr = UART_NR, .cons = MSM_CONSOLE, }; static atomic_t msm_uart_next_id = ATOMIC_INIT(0); static const struct of_device_id msm_uartdm_table[] = { { .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 }, { .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 }, { .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 }, { .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 }, { } }; static int msm_serial_probe(struct platform_device *pdev) { struct msm_port *msm_port; struct resource *resource; struct uart_port *port; const struct of_device_id *id; int irq, line; if (pdev->dev.of_node) line = of_alias_get_id(pdev->dev.of_node, "serial"); else line = pdev->id; if (line < 0) line = atomic_inc_return(&msm_uart_next_id) - 1; if (unlikely(line < 0 || line >= UART_NR)) return -ENXIO; dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line); port = msm_get_port_from_line(line); port->dev = &pdev->dev; msm_port = UART_TO_MSM(port); id = of_match_device(msm_uartdm_table, &pdev->dev); if (id) msm_port->is_uartdm = (unsigned long)id->data; else msm_port->is_uartdm = 0; msm_port->clk = devm_clk_get(&pdev->dev, "core"); if (IS_ERR(msm_port->clk)) return PTR_ERR(msm_port->clk); if (msm_port->is_uartdm) { 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); dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk); resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (unlikely(!resource)) return -ENXIO; port->mapbase = resource->start; irq = platform_get_irq(pdev, 0); if (unlikely(irq < 0)) return -ENXIO; port->irq = irq; platform_set_drvdata(pdev, port); return uart_add_one_port(&msm_uart_driver, port); } static int msm_serial_remove(struct platform_device *pdev) { struct uart_port *port = platform_get_drvdata(pdev); uart_remove_one_port(&msm_uart_driver, port); return 0; } static const struct of_device_id msm_match_table[] = { { .compatible = "qcom,msm-uart" }, { .compatible = "qcom,msm-uartdm" }, {} }; static struct platform_driver msm_platform_driver = { .remove = msm_serial_remove, .probe = msm_serial_probe, .driver = { .name = "msm_serial", .of_match_table = msm_match_table, }, }; static int __init msm_serial_init(void) { int ret; ret = uart_register_driver(&msm_uart_driver); if (unlikely(ret)) return ret; ret = platform_driver_register(&msm_platform_driver); if (unlikely(ret)) uart_unregister_driver(&msm_uart_driver); pr_info("msm_serial: driver initialized\n"); return ret; } static void __exit msm_serial_exit(void) { platform_driver_unregister(&msm_platform_driver); uart_unregister_driver(&msm_uart_driver); } module_init(msm_serial_init); module_exit(msm_serial_exit); MODULE_AUTHOR("Robert Love <rlove@google.com>"); MODULE_DESCRIPTION("Driver for msm7x serial device"); MODULE_LICENSE("GPL");