NVIDIA's Tegra has multiple UART controller which supports:
- APB DMA based controller fifo read/write.
- End Of Data interrupt in incoming data to know whether end
of frame achieve or not.
- HW controlled RTS and CTS flow control to reduce SW overhead.
Add serial driver to use all above feature.
Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
Acked-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---
Changes from V1:
- Remove port-number parameter and use the of_alias_get().
- put the ref count for the tty.
- rename the binding document file to serial-tegra.txt to match with
driver name.
- Remove falsy introduced line from Kconfig.
- Move platform data file to linux/platfor_data. Not removing the
platform datacompletely now. if it is requie to remove the will
be remove later along with other tegra driver also.
- Simplify tegra_uart_set_mctrl
- Clear flag for CMSPAR as driver dose not support this.
- Modify uart_get_baud_rate() to use actual baudrate.
- reorder compatibles in documentation file.
- used of_property_read_bool for modem interrupt.
- remove check if (pdev->dev.of_node) as it si always true.
- Drop devinit and devexit compiler option.
- nit cleanups for moving struture to the usage area.
Changes from V2:
- Rename the binding document to nvidia,tegra20-hsuart.txt
- Some nit cleanups and use Caps for aliases like APB, DMA, UART.
- Adding Alan's ack.
.../bindings/serial/nvidia,tegra20-hsuart.txt | 24 +
drivers/tty/serial/Kconfig | 11 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/serial-tegra.c | 1407 ++++++++++++++++++++
include/linux/platform_data/serial-tegra.h | 36 +
5 files changed, 1479 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt
create mode 100644 drivers/tty/serial/serial-tegra.c
create mode 100644 include/linux/platform_data/serial-tegra.h
diff --git a/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt b/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt
new file mode 100644
index 0000000..392a449
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt
@@ -0,0 +1,24 @@
+NVIDIA Tegra20/Tegra30 high speed (DMA based) UART controller driver.
+
+Required properties:
+- compatible : should be "nvidia,tegra30-hsuart", "nvidia,tegra20-hsuart".
+- reg: Should contain UART controller registers location and length.
+- interrupts: Should contain UART controller interrupts.
+- nvidia,dma-request-selector : The Tegra DMA controller's phandle and
+ request selector for this UART controller.
+
+Optional properties:
+- nvidia,enable-modem-interrupt: Enable modem interrupts. Should be enable
+ only if all 8 lines of UART controller are pinmuxed.
+
+Example:
+
+serial@70006000 {
+ compatible = "nvidia,tegra30-hsuart", "nvidia,tegra20-hsuart";
+ reg = <0x70006000 0x40>;
+ reg-shift = <2>;
+ interrupts = <0 36 0x04>;
+ nvidia,dma-request-selector = <&apbdma 8>;
+ nvidia,enable-modem-interrupt;
+ status = "disabled";
+};
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 59c23d0..aff3cd3 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -269,6 +269,17 @@ config SERIAL_SIRFSOC_CONSOLE
your boot loader about how to pass options to the kernel at
boot time.)
+config SERIAL_TEGRA
+ tristate "NVIDIA Tegra20/30 SoC serial controller"
+ depends on ARCH_TEGRA && TEGRA20_APB_DMA
+ select SERIAL_CORE
+ help
+ Support for the on-chip UARTs on the NVIDIA Tegra series SOCs
+ providing /dev/ttyHS0, 1, 2, 3 and 4 (note, some machines may not
+ provide all of these ports, depending on how the serial port
+ are enabled). This driver uses the APB DMA to achieve higher baudrate
+ and better performance.
+
config SERIAL_MAX3100
tristate "MAX3100 support"
depends on SPI
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index df1b998..82e4306 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -80,6 +80,7 @@ obj-$(CONFIG_SERIAL_MXS_AUART) += mxs-auart.o
obj-$(CONFIG_SERIAL_LANTIQ) += lantiq.o
obj-$(CONFIG_SERIAL_XILINX_PS_UART) += xilinx_uartps.o
obj-$(CONFIG_SERIAL_SIRFSOC) += sirfsoc_uart.o
+obj-$(CONFIG_SERIAL_TEGRA) += serial-tegra.o
obj-$(CONFIG_SERIAL_AR933X) += ar933x_uart.o
obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
new file mode 100644
index 0000000..0b7efb3
--- /dev/null
+++ b/drivers/tty/serial/serial-tegra.c
@@ -0,0 +1,1407 @@
+/*
+ * serial_tegra.c
+ *
+ * High-speed serial driver for NVIDIA Tegra SoCs
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Author: Laxman Dewangan <ldewangan@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pagemap.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/platform_data/serial-tegra.h>
+#include <linux/termios.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#include <mach/clk.h>
+
+#define TEGRA_UART_TYPE "TEGRA_UART"
+#define TX_EMPTY_STATUS (UART_LSR_TEMT | UART_LSR_THRE)
+#define BYTES_TO_ALIGN(x) ((unsigned long)(x) & 0x3)
+
+#define TEGRA_UART_RX_DMA_BUFFER_SIZE 4096
+#define TEGRA_UART_LSR_TXFIFO_FULL 0x100
+#define TEGRA_UART_IER_EORD 0x20
+#define TEGRA_UART_MCR_RTS_EN 0x40
+#define TEGRA_UART_MCR_CTS_EN 0x20
+#define TEGRA_UART_LSR_ANY (UART_LSR_OE | UART_LSR_BI | \
+ UART_LSR_PE | UART_LSR_FE)
+#define TEGRA_UART_IRDA_CSR 0x08
+#define TEGRA_UART_SIR_ENABLED 0x80
+
+#define TEGRA_UART_TX_PIO 1
+#define TEGRA_UART_TX_DMA 2
+#define TEGRA_UART_MIN_DMA 16
+#define TEGRA_UART_FIFO_SIZE 32
+
+/*
+ * Tx fifo trigger level setting in tegra uart is in
+ * reverse way then conventional uart.
+ */
+#define TEGRA_UART_TX_TRIG_16B 0x00
+#define TEGRA_UART_TX_TRIG_8B 0x10
+#define TEGRA_UART_TX_TRIG_4B 0x20
+#define TEGRA_UART_TX_TRIG_1B 0x30
+
+#define TEGRA_UART_MAXIMUM 5
+
+/* Default UART setting when started: 115200 no parity, stop, 8 data bits */
+#define TEGRA_UART_DEFAULT_BAUD 115200
+#define TEGRA_UART_DEFAULT_LSR UART_LCR_WLEN8
+
+/* Tx transfer mode */
+#define TEGRA_TX_PIO 1
+#define TEGRA_TX_DMA 2
+
+/**
+ * tegra_uart_chip_data: SOC specific data.
+ *
+ * @tx_fifo_full_status: Status flag available for checking tx fifo full.
+ * @allow_txfifo_reset_fifo_mode: allow_tx fifo reset with fifo mode or not.
+ * Tegra30 does not allow this.
+ * @support_clk_src_div: Clock source support the clock divider.
+ */
+struct tegra_uart_chip_data {
+ bool tx_fifo_full_status;
+ bool allow_txfifo_reset_fifo_mode;
+ bool support_clk_src_div;
+};
+
+struct tegra_uart_port {
+ struct uart_port uport;
+ const struct tegra_uart_chip_data *cdata;
+
+ struct clk *uart_clk;
+ unsigned int current_baud;
+
+ /* Register shadow */
+ unsigned long fcr_shadow;
+ unsigned long mcr_shadow;
+ unsigned long lcr_shadow;
+ unsigned long ier_shadow;
+ bool rts_active;
+
+ int tx_in_progress;
+ unsigned int tx_bytes;
+
+ bool enable_modem_interrupt;
+
+ bool rx_timeout;
+ int rx_in_progress;
+ int symb_bit;
+ int dma_req_sel;
+
+ struct dma_chan *rx_dma_chan;
+ struct dma_chan *tx_dma_chan;
+ dma_addr_t rx_dma_buf_phys;
+ dma_addr_t tx_dma_buf_phys;
+ unsigned char *rx_dma_buf_virt;
+ unsigned char *tx_dma_buf_virt;
+ struct dma_async_tx_descriptor *tx_dma_desc;
+ struct dma_async_tx_descriptor *rx_dma_desc;
+ dma_cookie_t tx_cookie;
+ dma_cookie_t rx_cookie;
+ int tx_bytes_requested;
+ int rx_bytes_requested;
+};
+
+static void tegra_uart_start_next_tx(struct tegra_uart_port *tup);
+static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup);
+
+static inline unsigned long tegra_uart_read(struct tegra_uart_port *tup,
+ unsigned long reg)
+{
+ return readl(tup->uport.membase + (reg << tup->uport.regshift));
+}
+
+static inline void tegra_uart_write(struct tegra_uart_port *tup, unsigned val,
+ unsigned long reg)
+{
+ writel(val, tup->uport.membase + (reg << tup->uport.regshift));
+}
+
+static inline struct tegra_uart_port *to_tegra_uport(struct uart_port *u)
+{
+ return container_of(u, struct tegra_uart_port, uport);
+}
+
+static unsigned int tegra_uart_get_mctrl(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+
+ /*
+ * RI - Ring detector is active
+ * CD/DCD/CAR - Carrier detect is always active. For some reason
+ * linux has different names for carrier detect.
+ * DSR - Data Set ready is active as the hardware doesn't support it.
+ * Don't know if the linux support this yet?
+ * CTS - Clear to send. Always set to active, as the hardware handles
+ * CTS automatically.
+ */
+ if (tup->enable_modem_interrupt)
+ return TIOCM_RI | TIOCM_CD | TIOCM_DSR | TIOCM_CTS;
+ return TIOCM_CTS;
+}
+
+static void set_rts(struct tegra_uart_port *tup, bool active)
+{
+ unsigned long mcr;
+
+ mcr = tup->mcr_shadow;
+ if (active)
+ mcr |= TEGRA_UART_MCR_RTS_EN;
+ else
+ mcr &= ~TEGRA_UART_MCR_RTS_EN;
+ if (mcr != tup->mcr_shadow) {
+ tegra_uart_write(tup, mcr, UART_MCR);
+ tup->mcr_shadow = mcr;
+ }
+ return;
+}
+
+static void set_dtr(struct tegra_uart_port *tup, bool active)
+{
+ unsigned long mcr;
+
+ mcr = tup->mcr_shadow;
+ if (active)
+ mcr |= UART_MCR_DTR;
+ else
+ mcr &= ~UART_MCR_DTR;
+ if (mcr != tup->mcr_shadow) {
+ tegra_uart_write(tup, mcr, UART_MCR);
+ tup->mcr_shadow = mcr;
+ }
+ return;
+}
+
+static void tegra_uart_set_mctrl(struct uart_port *u, unsigned int mctrl)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ unsigned long mcr;
+ int dtr_enable;
+
+ mcr = tup->mcr_shadow;
+ tup->rts_active = !!(mctrl & TIOCM_RTS);
+ set_rts(tup, tup->rts_active);
+
+ dtr_enable = !!(mctrl & TIOCM_DTR);
+ set_dtr(tup, dtr_enable);
+ return;
+}
+
+static void tegra_uart_break_ctl(struct uart_port *u, int break_ctl)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ unsigned long lcr;
+
+ lcr = tup->lcr_shadow;
+ if (break_ctl)
+ lcr |= UART_LCR_SBC;
+ else
+ lcr &= ~UART_LCR_SBC;
+ tegra_uart_write(tup, lcr, UART_LCR);
+ tup->lcr_shadow = lcr;
+}
+
+/* Wait for a symbol-time. */
+static void tegra_uart_wait_sym_time(struct tegra_uart_port *tup,
+ unsigned int syms)
+{
+ if (tup->current_baud)
+ udelay(DIV_ROUND_UP(syms * tup->symb_bit * 1000000,
+ tup->current_baud));
+}
+
+static void tegra_uart_fifo_reset(struct tegra_uart_port *tup, u8 fcr_bits)
+{
+ unsigned long fcr = tup->fcr_shadow;
+
+ if (tup->cdata->allow_txfifo_reset_fifo_mode) {
+ fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+ tegra_uart_write(tup, fcr, UART_FCR);
+ } else {
+ fcr &= ~UART_FCR_ENABLE_FIFO;
+ tegra_uart_write(tup, fcr, UART_FCR);
+ udelay(60);
+ fcr |= fcr_bits & (UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
+ tegra_uart_write(tup, fcr, UART_FCR);
+ fcr |= UART_FCR_ENABLE_FIFO;
+ tegra_uart_write(tup, fcr, UART_FCR);
+ }
+
+ /* Dummy read to ensure the write is posted */
+ tegra_uart_read(tup, UART_SCR);
+
+ /* Wait for the flush to propagate. */
+ tegra_uart_wait_sym_time(tup, 1);
+}
+
+static int tegra_set_baudrate(struct tegra_uart_port *tup, unsigned int baud)
+{
+ unsigned long rate;
+ unsigned int divisor;
+ unsigned long lcr;
+ int ret;
+
+ if (tup->current_baud == baud)
+ return 0;
+
+ if (tup->cdata->support_clk_src_div) {
+ rate = baud * 16;
+ ret = clk_set_rate(tup->uart_clk, rate);
+ if (ret < 0) {
+ dev_err(tup->uport.dev,
+ "clk_set_rate() failed for rate %lu\n", rate);
+ return ret;
+ }
+ divisor = 1;
+ } else {
+ rate = clk_get_rate(tup->uart_clk);
+ divisor = DIV_ROUND_CLOSEST(rate, baud * 16);
+ }
+
+ lcr = tup->lcr_shadow;
+ lcr |= UART_LCR_DLAB;
+ tegra_uart_write(tup, lcr, UART_LCR);
+
+ tegra_uart_write(tup, divisor & 0xFF, UART_TX);
+ tegra_uart_write(tup, ((divisor >> 8) & 0xFF), UART_IER);
+
+ lcr &= ~UART_LCR_DLAB;
+ tegra_uart_write(tup, lcr, UART_LCR);
+
+ /* Dummy read to ensure the write is posted */
+ tegra_uart_read(tup, UART_SCR);
+
+ tup->current_baud = baud;
+
+ /* wait two character intervals at new rate */
+ tegra_uart_wait_sym_time(tup, 2);
+ return 0;
+}
+
+static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
+ unsigned long lsr)
+{
+ char flag = TTY_NORMAL;
+
+ if (unlikely(lsr & TEGRA_UART_LSR_ANY)) {
+ if (lsr & UART_LSR_OE) {
+ /* Overrrun error */
+ flag |= TTY_OVERRUN;
+ tup->uport.icount.overrun++;
+ dev_err(tup->uport.dev, "Got overrun errors\n");
+ } else if (lsr & UART_LSR_PE) {
+ /* Parity error */
+ flag |= TTY_PARITY;
+ tup->uport.icount.parity++;
+ dev_err(tup->uport.dev, "Got Parity errors\n");
+ } else if (lsr & UART_LSR_FE) {
+ flag |= TTY_FRAME;
+ tup->uport.icount.frame++;
+ dev_err(tup->uport.dev, "Got frame errors\n");
+ } else if (lsr & UART_LSR_BI) {
+ dev_err(tup->uport.dev, "Got Break\n");
+ tup->uport.icount.brk++;
+ /* If FIFO read error without any data, reset Rx FIFO */
+ if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
+ tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
+ }
+ }
+ return flag;
+}
+
+static int tegra_uart_request_port(struct uart_port *u)
+{
+ return 0;
+}
+
+static void tegra_uart_release_port(struct uart_port *u)
+{
+ /* Nothing to do here */
+}
+
+static void tegra_uart_fill_tx_fifo(struct tegra_uart_port *tup, int max_bytes)
+{
+ struct circ_buf *xmit = &tup->uport.state->xmit;
+ int i;
+
+ for (i = 0; i < max_bytes; i++) {
+ BUG_ON(uart_circ_empty(xmit));
+ if (tup->cdata->tx_fifo_full_status) {
+ unsigned long lsr = tegra_uart_read(tup, UART_LSR);
+ if ((lsr & TEGRA_UART_LSR_TXFIFO_FULL))
+ break;
+ }
+ tegra_uart_write(tup, xmit->buf[xmit->tail], UART_TX);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ tup->uport.icount.tx++;
+ }
+}
+
+static void tegra_uart_start_pio_tx(struct tegra_uart_port *tup,
+ unsigned int bytes)
+{
+ if (bytes > TEGRA_UART_MIN_DMA)
+ bytes = TEGRA_UART_MIN_DMA;
+
+ tup->tx_in_progress = TEGRA_UART_TX_PIO;
+ tup->tx_bytes = bytes;
+ tup->ier_shadow |= UART_IER_THRI;
+ tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+}
+
+static void tegra_uart_tx_dma_complete(void *args)
+{
+ struct tegra_uart_port *tup = args;
+ struct circ_buf *xmit = &tup->uport.state->xmit;
+ struct dma_tx_state state;
+ unsigned long flags;
+ int count;
+
+ dmaengine_tx_status(tup->tx_dma_chan, tup->rx_cookie, &state);
+ count = tup->tx_bytes_requested - state.residue;
+ async_tx_ack(tup->tx_dma_desc);
+ spin_lock_irqsave(&tup->uport.lock, flags);
+ xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
+ tup->tx_in_progress = 0;
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&tup->uport);
+ tegra_uart_start_next_tx(tup);
+ spin_unlock_irqrestore(&tup->uport.lock, flags);
+}
+
+static int tegra_uart_start_tx_dma(struct tegra_uart_port *tup,
+ unsigned long count)
+{
+ struct circ_buf *xmit = &tup->uport.state->xmit;
+ dma_addr_t tx_phys_addr;
+
+ dma_sync_single_for_device(tup->uport.dev, tup->tx_dma_buf_phys,
+ UART_XMIT_SIZE, DMA_TO_DEVICE);
+
+ tup->tx_bytes = count & ~(0xF);
+ tx_phys_addr = tup->tx_dma_buf_phys + xmit->tail;
+ tup->tx_dma_desc = dmaengine_prep_slave_single(tup->tx_dma_chan,
+ tx_phys_addr, tup->tx_bytes, DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT);
+ if (!tup->tx_dma_desc) {
+ dev_err(tup->uport.dev, "Not able to get desc for Tx\n");
+ return -EIO;
+ }
+
+ tup->tx_dma_desc->callback = tegra_uart_tx_dma_complete;
+ tup->tx_dma_desc->callback_param = tup;
+ tup->tx_in_progress = TEGRA_UART_TX_DMA;
+ tup->tx_bytes_requested = tup->tx_bytes;
+ tup->tx_cookie = dmaengine_submit(tup->tx_dma_desc);
+ dma_async_issue_pending(tup->tx_dma_chan);
+ return 0;
+}
+
+static void tegra_uart_start_next_tx(struct tegra_uart_port *tup)
+{
+ unsigned long tail;
+ unsigned long count;
+ struct circ_buf *xmit = &tup->uport.state->xmit;
+
+ tail = (unsigned long)&xmit->buf[xmit->tail];
+ count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
+ if (!count)
+ return;
+
+ if (count < TEGRA_UART_MIN_DMA)
+ tegra_uart_start_pio_tx(tup, count);
+ else if (BYTES_TO_ALIGN(tail) > 0)
+ tegra_uart_start_pio_tx(tup, BYTES_TO_ALIGN(tail));
+ else
+ tegra_uart_start_tx_dma(tup, count);
+}
+
+/* Called by serial core driver with u->lock taken. */
+static void tegra_uart_start_tx(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ struct circ_buf *xmit = &u->state->xmit;
+
+ if (!uart_circ_empty(xmit) && !tup->tx_in_progress)
+ tegra_uart_start_next_tx(tup);
+}
+
+static unsigned int tegra_uart_tx_empty(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ unsigned int ret = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&u->lock, flags);
+ if (!tup->tx_in_progress) {
+ unsigned long lsr = tegra_uart_read(tup, UART_LSR);
+ if ((lsr & TX_EMPTY_STATUS) == TX_EMPTY_STATUS)
+ ret = TIOCSER_TEMT;
+ }
+ spin_unlock_irqrestore(&u->lock, flags);
+ return ret;
+}
+
+static void tegra_uart_stop_tx(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ struct circ_buf *xmit = &tup->uport.state->xmit;
+ struct dma_tx_state state;
+ int count;
+
+ dmaengine_terminate_all(tup->tx_dma_chan);
+ dmaengine_tx_status(tup->tx_dma_chan, tup->tx_cookie, &state);
+ count = tup->tx_bytes_requested - state.residue;
+ async_tx_ack(tup->tx_dma_desc);
+ xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
+ tup->tx_in_progress = 0;
+ return;
+}
+
+static void tegra_uart_handle_tx_pio(struct tegra_uart_port *tup)
+{
+ struct circ_buf *xmit = &tup->uport.state->xmit;
+
+ tegra_uart_fill_tx_fifo(tup, tup->tx_bytes);
+ tup->tx_in_progress = 0;
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&tup->uport);
+ tegra_uart_start_next_tx(tup);
+ return;
+}
+
+static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup,
+ struct tty_struct *tty)
+{
+ do {
+ char flag = TTY_NORMAL;
+ unsigned long lsr = 0;
+ unsigned char ch;
+
+ lsr = tegra_uart_read(tup, UART_LSR);
+ if (!(lsr & UART_LSR_DR))
+ break;
+
+ flag = tegra_uart_decode_rx_error(tup, lsr);
+ ch = (unsigned char) tegra_uart_read(tup, UART_RX);
+ tup->uport.icount.rx++;
+
+ if (!uart_handle_sysrq_char(&tup->uport, ch) && tty)
+ tty_insert_flip_char(tty, ch, flag);
+ } while (1);
+
+ return;
+}
+
+static void tegra_uart_copy_rx_to_tty(struct tegra_uart_port *tup,
+ struct tty_struct *tty, int count)
+{
+ int copied;
+
+ tup->uport.icount.rx += count;
+ if (!tty) {
+ dev_err(tup->uport.dev, "No tty port\n");
+ return;
+ }
+ dma_sync_single_for_cpu(tup->uport.dev, tup->rx_dma_buf_phys,
+ TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_FROM_DEVICE);
+ copied = tty_insert_flip_string(tty,
+ ((unsigned char *)(tup->rx_dma_buf_virt)), count);
+ if (copied != count) {
+ WARN_ON(1);
+ dev_err(tup->uport.dev, "RxData copy to tty layer failed\n");
+ }
+ dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
+ TEGRA_UART_RX_DMA_BUFFER_SIZE, DMA_TO_DEVICE);
+}
+
+static void tegra_uart_rx_dma_complete(void *args)
+{
+ struct tegra_uart_port *tup = args;
+ struct uart_port *u = &tup->uport;
+ int count = tup->rx_bytes_requested;
+ struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
+ unsigned long flags;
+
+ async_tx_ack(tup->rx_dma_desc);
+ spin_lock_irqsave(&u->lock, flags);
+
+ /* Deactivate flow control to stop sender */
+ if (tup->rts_active)
+ set_rts(tup, false);
+
+ /* If we are here, DMA is stopped */
+ if (count)
+ tegra_uart_copy_rx_to_tty(tup, tty, count);
+
+ tegra_uart_handle_rx_pio(tup, tty);
+ if (tty) {
+ tty_flip_buffer_push(tty);
+ tty_kref_put(tty);
+ }
+ tegra_uart_start_rx_dma(tup);
+
+ /* Activate flow control to start transfer */
+ if (tup->rts_active)
+ set_rts(tup, true);
+
+ spin_unlock_irqrestore(&u->lock, flags);
+}
+
+static void tegra_uart_handle_rx_dma(struct tegra_uart_port *tup)
+{
+ struct dma_tx_state state;
+ struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
+ int count;
+
+ /* Deactivate flow control to stop sender */
+ if (tup->rts_active)
+ set_rts(tup, false);
+
+ dmaengine_terminate_all(tup->rx_dma_chan);
+ dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
+ count = tup->rx_bytes_requested - state.residue;
+
+ /* If we are here, DMA is stopped */
+ if (count)
+ tegra_uart_copy_rx_to_tty(tup, tty, count);
+
+ tegra_uart_handle_rx_pio(tup, tty);
+ if (tty) {
+ tty_flip_buffer_push(tty);
+ tty_kref_put(tty);
+ }
+ tegra_uart_start_rx_dma(tup);
+
+ if (tup->rts_active)
+ set_rts(tup, true);
+}
+
+static int tegra_uart_start_rx_dma(struct tegra_uart_port *tup)
+{
+ unsigned int count = TEGRA_UART_RX_DMA_BUFFER_SIZE;
+
+ tup->rx_dma_desc = dmaengine_prep_slave_single(tup->rx_dma_chan,
+ tup->rx_dma_buf_phys, count, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT);
+ if (!tup->rx_dma_desc) {
+ dev_err(tup->uport.dev, "Not able to get desc for Rx\n");
+ return -EIO;
+ }
+
+ tup->rx_dma_desc->callback = tegra_uart_rx_dma_complete;
+ tup->rx_dma_desc->callback_param = tup;
+ dma_sync_single_for_device(tup->uport.dev, tup->rx_dma_buf_phys,
+ count, DMA_TO_DEVICE);
+ tup->rx_bytes_requested = count;
+ tup->rx_cookie = dmaengine_submit(tup->rx_dma_desc);
+ dma_async_issue_pending(tup->rx_dma_chan);
+ return 0;
+}
+
+static void tegra_uart_handle_modem_signal_change(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ unsigned long msr;
+
+ msr = tegra_uart_read(tup, UART_MSR);
+ if (!(msr & UART_MSR_ANY_DELTA))
+ return;
+
+ if (msr & UART_MSR_TERI)
+ tup->uport.icount.rng++;
+ if (msr & UART_MSR_DDSR)
+ tup->uport.icount.dsr++;
+ /* We may only get DDCD when HW init and reset */
+ if (msr & UART_MSR_DDCD)
+ uart_handle_dcd_change(&tup->uport, msr & UART_MSR_DCD);
+ /* Will start/stop_tx accordingly */
+ if (msr & UART_MSR_DCTS)
+ uart_handle_cts_change(&tup->uport, msr & UART_MSR_CTS);
+ return;
+}
+
+static irqreturn_t tegra_uart_isr(int irq, void *data)
+{
+ struct tegra_uart_port *tup = data;
+ struct uart_port *u = &tup->uport;
+ unsigned long iir;
+ unsigned long ier;
+ bool is_rx_int = false;
+ unsigned long flags;
+
+ spin_lock_irqsave(&u->lock, flags);
+ while (1) {
+ iir = tegra_uart_read(tup, UART_IIR);
+ if (iir & UART_IIR_NO_INT) {
+ if (is_rx_int) {
+ tegra_uart_handle_rx_dma(tup);
+ if (tup->rx_in_progress) {
+ ier = tup->ier_shadow;
+ ier |= (UART_IER_RLSI | UART_IER_RTOIE |
+ TEGRA_UART_IER_EORD);
+ tup->ier_shadow = ier;
+ tegra_uart_write(tup, ier, UART_IER);
+ }
+ }
+ spin_unlock_irqrestore(&u->lock, flags);
+ return IRQ_HANDLED;
+ }
+
+ switch ((iir >> 1) & 0x7) {
+ case 0: /* Modem signal change interrupt */
+ tegra_uart_handle_modem_signal_change(u);
+ break;
+
+ case 1: /* Transmit interrupt only triggered when using PIO */
+ tup->ier_shadow &= ~UART_IER_THRI;
+ tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+ tegra_uart_handle_tx_pio(tup);
+ break;
+
+ case 4: /* End of data */
+ case 6: /* Rx timeout */
+ case 2: /* Receive */
+ if (!is_rx_int) {
+ is_rx_int = true;
+ /* Disable Rx interrupts */
+ ier = tup->ier_shadow;
+ ier |= UART_IER_RDI;
+ tegra_uart_write(tup, ier, UART_IER);
+ ier &= ~(UART_IER_RDI | UART_IER_RLSI |
+ UART_IER_RTOIE | TEGRA_UART_IER_EORD);
+ tup->ier_shadow = ier;
+ tegra_uart_write(tup, ier, UART_IER);
+ }
+ break;
+
+ case 3: /* Receive error */
+ tegra_uart_decode_rx_error(tup,
+ tegra_uart_read(tup, UART_LSR));
+ break;
+
+ case 5: /* break nothing to handle */
+ case 7: /* break nothing to handle */
+ break;
+ }
+ }
+}
+
+static void tegra_uart_stop_rx(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ struct tty_struct *tty = tty_port_tty_get(&tup->uport.state->port);
+ struct dma_tx_state state;
+ unsigned long ier;
+ int count;
+
+ if (tup->rts_active)
+ set_rts(tup, false);
+
+ if (!tup->rx_in_progress)
+ return;
+
+ tegra_uart_wait_sym_time(tup, 1); /* wait a character interval */
+
+ ier = tup->ier_shadow;
+ ier &= ~(UART_IER_RDI | UART_IER_RLSI | UART_IER_RTOIE |
+ TEGRA_UART_IER_EORD);
+ tup->ier_shadow = ier;
+ tegra_uart_write(tup, ier, UART_IER);
+ tup->rx_in_progress = 0;
+ if (tup->rx_dma_chan) {
+ dmaengine_terminate_all(tup->rx_dma_chan);
+ dmaengine_tx_status(tup->rx_dma_chan, tup->rx_cookie, &state);
+ async_tx_ack(tup->rx_dma_desc);
+ count = tup->rx_bytes_requested - state.residue;
+ tegra_uart_copy_rx_to_tty(tup, tty, count);
+ tegra_uart_handle_rx_pio(tup, tty);
+ } else {
+ tegra_uart_handle_rx_pio(tup, tty);
+ }
+ if (tty) {
+ tty_flip_buffer_push(tty);
+ tty_kref_put(tty);
+ }
+ return;
+}
+
+static void tegra_uart_hw_deinit(struct tegra_uart_port *tup)
+{
+ unsigned long flags;
+ unsigned long char_time = DIV_ROUND_UP(10000000, tup->current_baud);
+ unsigned long fifo_empty_time = tup->uport.fifosize * char_time;
+ unsigned long wait_time;
+ unsigned long lsr;
+ unsigned long msr;
+ unsigned long mcr;
+
+ /* Disable interrupts */
+ tegra_uart_write(tup, 0, UART_IER);
+
+ lsr = tegra_uart_read(tup, UART_LSR);
+ if ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
+ msr = tegra_uart_read(tup, UART_MSR);
+ mcr = tegra_uart_read(tup, UART_MCR);
+ if ((mcr & TEGRA_UART_MCR_CTS_EN) && (msr & UART_MSR_CTS))
+ dev_err(tup->uport.dev,
+ "Tx Fifo not empty, CTS disabled, waiting\n");
+
+ /* Wait for Tx fifo to be empty */
+ while ((lsr & UART_LSR_TEMT) != UART_LSR_TEMT) {
+ wait_time = min(fifo_empty_time, 100lu);
+ udelay(wait_time);
+ fifo_empty_time -= wait_time;
+ if (!fifo_empty_time) {
+ msr = tegra_uart_read(tup, UART_MSR);
+ mcr = tegra_uart_read(tup, UART_MCR);
+ if ((mcr & TEGRA_UART_MCR_CTS_EN) &&
+ (msr & UART_MSR_CTS))
+ dev_err(tup->uport.dev,
+ "Slave not ready\n");
+ break;
+ }
+ lsr = tegra_uart_read(tup, UART_LSR);
+ }
+ }
+
+ spin_lock_irqsave(&tup->uport.lock, flags);
+ /* Reset the Rx and Tx FIFOs */
+ tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
+ tup->current_baud = 0;
+ spin_unlock_irqrestore(&tup->uport.lock, flags);
+
+ clk_disable_unprepare(tup->uart_clk);
+}
+
+static int tegra_uart_hw_init(struct tegra_uart_port *tup)
+{
+ int ret;
+
+ tup->fcr_shadow = 0;
+ tup->mcr_shadow = 0;
+ tup->lcr_shadow = 0;
+ tup->ier_shadow = 0;
+ tup->current_baud = 0;
+
+ clk_prepare_enable(tup->uart_clk);
+
+ /* Reset the UART controller to clear all previous status.*/
+ tegra_periph_reset_assert(tup->uart_clk);
+ udelay(10);
+ tegra_periph_reset_deassert(tup->uart_clk);
+
+ tup->rx_in_progress = 0;
+ tup->tx_in_progress = 0;
+
+ /*
+ * Set the trigger level
+ *
+ * For PIO mode:
+ *
+ * For receive, this will interrupt the CPU after that many number of
+ * bytes are received, for the remaining bytes the receive timeout
+ * interrupt is received. Rx high watermark is set to 4.
+ *
+ * For transmit, if the trasnmit interrupt is enabled, this will
+ * interrupt the CPU when the number of entries in the FIFO reaches the
+ * low watermark. Tx low watermark is set to 16 bytes.
+ *
+ * For DMA mode:
+ *
+ * Set the Tx trigger to 16. This should match the DMA burst size that
+ * programmed in the DMA registers.
+ */
+ tup->fcr_shadow = UART_FCR_ENABLE_FIFO;
+ tup->fcr_shadow |= UART_FCR_R_TRIG_01;
+ tup->fcr_shadow |= TEGRA_UART_TX_TRIG_16B;
+ tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
+
+ /*
+ * Initialize the UART with default configuration
+ * (115200, N, 8, 1) so that the receive DMA buffer may be
+ * enqueued
+ */
+ tup->lcr_shadow = TEGRA_UART_DEFAULT_LSR;
+ tegra_set_baudrate(tup, TEGRA_UART_DEFAULT_BAUD);
+ tup->fcr_shadow |= UART_FCR_DMA_SELECT;
+ tegra_uart_write(tup, tup->fcr_shadow, UART_FCR);
+
+ ret = tegra_uart_start_rx_dma(tup);
+ if (ret < 0) {
+ dev_err(tup->uport.dev, "Not able to start Rx DMA\n");
+ return ret;
+ }
+ tup->rx_in_progress = 1;
+
+ /*
+ * Enable IE_RXS for the receive status interrupts like line errros.
+ * Enable IE_RX_TIMEOUT to get the bytes which cannot be DMA'd.
+ *
+ * If using DMA mode, enable EORD instead of receive interrupt which
+ * will interrupt after the UART is done with the receive instead of
+ * the interrupt when the FIFO "threshold" is reached.
+ *
+ * EORD is different interrupt than RX_TIMEOUT - RX_TIMEOUT occurs when
+ * the DATA is sitting in the FIFO and couldn't be transferred to the
+ * DMA as the DMA size alignment(4 bytes) is not met. EORD will be
+ * triggered when there is a pause of the incomming data stream for 4
+ * characters long.
+ *
+ * For pauses in the data which is not aligned to 4 bytes, we get
+ * both the EORD as well as RX_TIMEOUT - SW sees RX_TIMEOUT first
+ * then the EORD.
+ */
+ tup->ier_shadow = UART_IER_RLSI | UART_IER_RTOIE | TEGRA_UART_IER_EORD;
+ tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+ return 0;
+}
+
+static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
+ bool dma_to_memory)
+{
+ struct dma_chan *dma_chan;
+ unsigned char *dma_buf;
+ dma_addr_t dma_phys;
+ int ret;
+ struct dma_slave_config dma_sconfig;
+ dma_cap_mask_t mask;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ dma_chan = dma_request_channel(mask, NULL, NULL);
+ if (!dma_chan) {
+ dev_err(tup->uport.dev,
+ "Dma channel is not available, will try later\n");
+ return -EPROBE_DEFER;
+ }
+
+ if (dma_to_memory) {
+ dma_buf = dma_alloc_coherent(tup->uport.dev,
+ TEGRA_UART_RX_DMA_BUFFER_SIZE,
+ &dma_phys, GFP_KERNEL);
+ if (!dma_buf) {
+ dev_err(tup->uport.dev,
+ "Not able to allocate the dma buffer\n");
+ dma_release_channel(dma_chan);
+ return -ENOMEM;
+ }
+ } else {
+ dma_phys = dma_map_single(tup->uport.dev,
+ tup->uport.state->xmit.buf, UART_XMIT_SIZE,
+ DMA_TO_DEVICE);
+ dma_buf = tup->uport.state->xmit.buf;
+ }
+
+ dma_sconfig.slave_id = tup->dma_req_sel;
+ if (dma_to_memory) {
+ dma_sconfig.src_addr = tup->uport.mapbase;
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.src_maxburst = 4;
+ } else {
+ dma_sconfig.dst_addr = tup->uport.mapbase;
+ dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ dma_sconfig.dst_maxburst = 16;
+ }
+
+ ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
+ if (ret < 0) {
+ dev_err(tup->uport.dev,
+ "Dma slave config failed, err = %d\n", ret);
+ goto scrub;
+ }
+
+ if (dma_to_memory) {
+ tup->rx_dma_chan = dma_chan;
+ tup->rx_dma_buf_virt = dma_buf;
+ tup->rx_dma_buf_phys = dma_phys;
+ } else {
+ tup->tx_dma_chan = dma_chan;
+ tup->tx_dma_buf_virt = dma_buf;
+ tup->tx_dma_buf_phys = dma_phys;
+ }
+ return 0;
+
+scrub:
+ dma_release_channel(dma_chan);
+ return ret;
+}
+
+static void tegra_uart_dma_channel_free(struct tegra_uart_port *tup,
+ bool dma_to_memory)
+{
+ struct dma_chan *dma_chan;
+
+ if (dma_to_memory) {
+ dma_free_coherent(tup->uport.dev, TEGRA_UART_RX_DMA_BUFFER_SIZE,
+ tup->rx_dma_buf_virt, tup->rx_dma_buf_phys);
+ dma_chan = tup->rx_dma_chan;
+ tup->rx_dma_chan = NULL;
+ tup->rx_dma_buf_phys = 0;
+ tup->rx_dma_buf_virt = NULL;
+ } else {
+ dma_unmap_single(tup->uport.dev, tup->tx_dma_buf_phys,
+ UART_XMIT_SIZE, DMA_TO_DEVICE);
+ dma_chan = tup->tx_dma_chan;
+ tup->tx_dma_chan = NULL;
+ tup->tx_dma_buf_phys = 0;
+ tup->tx_dma_buf_virt = NULL;
+ }
+ dma_release_channel(dma_chan);
+}
+
+static int tegra_uart_startup(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ int ret;
+
+ ret = tegra_uart_dma_channel_allocate(tup, false);
+ if (ret < 0) {
+ dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", ret);
+ return ret;
+ }
+
+ ret = tegra_uart_dma_channel_allocate(tup, true);
+ if (ret < 0) {
+ dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", ret);
+ goto fail_rx_dma;
+ }
+
+ ret = tegra_uart_hw_init(tup);
+ if (ret < 0) {
+ dev_err(u->dev, "Uart HW init failed, err = %d\n", ret);
+ goto fail_hw_init;
+ }
+
+ ret = request_irq(u->irq, tegra_uart_isr, IRQF_DISABLED,
+ dev_name(u->dev), tup);
+ if (ret < 0) {
+ dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq);
+ goto fail_hw_init;
+ }
+ return 0;
+
+fail_hw_init:
+ tegra_uart_dma_channel_free(tup, true);
+fail_rx_dma:
+ tegra_uart_dma_channel_free(tup, false);
+ return ret;
+}
+
+static void tegra_uart_shutdown(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+
+ tegra_uart_hw_deinit(tup);
+
+ tup->rx_in_progress = 0;
+ tup->tx_in_progress = 0;
+
+ tegra_uart_dma_channel_free(tup, true);
+ tegra_uart_dma_channel_free(tup, false);
+ free_irq(u->irq, tup);
+}
+
+static void tegra_uart_enable_ms(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+
+ if (tup->enable_modem_interrupt) {
+ tup->ier_shadow |= UART_IER_MSI;
+ tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+ }
+}
+
+static void tegra_uart_set_termios(struct uart_port *u,
+ struct ktermios *termios, struct ktermios *oldtermios)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+ unsigned int baud;
+ unsigned long flags;
+ unsigned int lcr;
+ int symb_bit = 1;
+ struct clk *parent_clk = clk_get_parent(tup->uart_clk);
+ unsigned long parent_clk_rate = clk_get_rate(parent_clk);
+ int max_divider = (tup->cdata->support_clk_src_div) ? 0x7FFF : 0xFFFF;
+
+ max_divider *= 16;
+ spin_lock_irqsave(&u->lock, flags);
+
+ /* Changing configuration, it is safe to stop any rx now */
+ if (tup->rts_active)
+ set_rts(tup, false);
+
+ /* Clear all interrupts as configuration is going to be change */
+ tegra_uart_write(tup, tup->ier_shadow | UART_IER_RDI, UART_IER);
+ tegra_uart_read(tup, UART_IER);
+ tegra_uart_write(tup, 0, UART_IER);
+ tegra_uart_read(tup, UART_IER);
+
+ /* Parity */
+ lcr = tup->lcr_shadow;
+ lcr &= ~UART_LCR_PARITY;
+
+ /* CMSPAR isn't supported by this driver */
+ termios->c_cflag &= ~CMSPAR;
+
+ if ((termios->c_cflag & PARENB) == PARENB) {
+ symb_bit++;
+ if (termios->c_cflag & PARODD) {
+ lcr |= UART_LCR_PARITY;
+ lcr &= ~UART_LCR_EPAR;
+ lcr &= ~UART_LCR_SPAR;
+ } else {
+ lcr |= UART_LCR_PARITY;
+ lcr |= UART_LCR_EPAR;
+ lcr &= ~UART_LCR_SPAR;
+ }
+ }
+
+ lcr &= ~UART_LCR_WLEN8;
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ lcr |= UART_LCR_WLEN5;
+ symb_bit += 5;
+ break;
+ case CS6:
+ lcr |= UART_LCR_WLEN6;
+ symb_bit += 6;
+ break;
+ case CS7:
+ lcr |= UART_LCR_WLEN7;
+ symb_bit += 7;
+ break;
+ default:
+ lcr |= UART_LCR_WLEN8;
+ symb_bit += 8;
+ break;
+ }
+
+ /* Stop bits */
+ if (termios->c_cflag & CSTOPB) {
+ lcr |= UART_LCR_STOP;
+ symb_bit += 2;
+ } else {
+ lcr &= ~UART_LCR_STOP;
+ symb_bit++;
+ }
+
+ tegra_uart_write(tup, lcr, UART_LCR);
+ tup->lcr_shadow = lcr;
+ tup->symb_bit = symb_bit;
+
+ /* Baud rate. */
+ baud = uart_get_baud_rate(u, termios, oldtermios,
+ parent_clk_rate/max_divider,
+ parent_clk_rate/16);
+ spin_unlock_irqrestore(&u->lock, flags);
+ tegra_set_baudrate(tup, baud);
+ if (tty_termios_baud_rate(termios))
+ tty_termios_encode_baud_rate(termios, baud, baud);
+ spin_lock_irqsave(&u->lock, flags);
+
+ /* Flow control */
+ if (termios->c_cflag & CRTSCTS) {
+ tup->mcr_shadow |= TEGRA_UART_MCR_CTS_EN;
+ tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
+ tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
+ /* if top layer has asked to set rts active then do so here */
+ if (tup->rts_active)
+ set_rts(tup, true);
+ } else {
+ tup->mcr_shadow &= ~TEGRA_UART_MCR_CTS_EN;
+ tup->mcr_shadow &= ~TEGRA_UART_MCR_RTS_EN;
+ tegra_uart_write(tup, tup->mcr_shadow, UART_MCR);
+ }
+
+ /* update the port timeout based on new settings */
+ uart_update_timeout(u, termios->c_cflag, baud);
+
+ /* Make sure all write has completed */
+ tegra_uart_read(tup, UART_IER);
+
+ /* Reenable interrupt */
+ tegra_uart_write(tup, tup->ier_shadow, UART_IER);
+ tegra_uart_read(tup, UART_IER);
+
+ spin_unlock_irqrestore(&u->lock, flags);
+ return;
+}
+
+/*
+ * Flush any TX data submitted for DMA and PIO. Called when the
+ * TX circular buffer is reset.
+ */
+static void tegra_uart_flush_buffer(struct uart_port *u)
+{
+ struct tegra_uart_port *tup = to_tegra_uport(u);
+
+ tup->tx_bytes = 0;
+ if (tup->tx_dma_chan)
+ dmaengine_terminate_all(tup->tx_dma_chan);
+ return;
+}
+
+static const char *tegra_uart_type(struct uart_port *u)
+{
+ return TEGRA_UART_TYPE;
+}
+
+static struct uart_ops tegra_uart_ops = {
+ .tx_empty = tegra_uart_tx_empty,
+ .set_mctrl = tegra_uart_set_mctrl,
+ .get_mctrl = tegra_uart_get_mctrl,
+ .stop_tx = tegra_uart_stop_tx,
+ .start_tx = tegra_uart_start_tx,
+ .stop_rx = tegra_uart_stop_rx,
+ .flush_buffer = tegra_uart_flush_buffer,
+ .enable_ms = tegra_uart_enable_ms,
+ .break_ctl = tegra_uart_break_ctl,
+ .startup = tegra_uart_startup,
+ .shutdown = tegra_uart_shutdown,
+ .set_termios = tegra_uart_set_termios,
+ .type = tegra_uart_type,
+ .request_port = tegra_uart_request_port,
+ .release_port = tegra_uart_release_port,
+};
+
+static struct uart_driver tegra_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "tegra_hsuart",
+ .dev_name = "ttyTHS",
+ .cons = 0,
+ .nr = TEGRA_UART_MAXIMUM,
+};
+
+static int tegra_uart_parse_dt(struct platform_device *pdev,
+ struct tegra_uart_port *tup)
+{
+ struct device_node *np = pdev->dev.of_node;
+ u32 of_dma[2];
+ int port;
+
+ if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
+ of_dma, 2) >= 0) {
+ tup->dma_req_sel = of_dma[1];
+ } else {
+ dev_err(&pdev->dev, "missing dma requestor in device tree\n");
+ return -EINVAL;
+ }
+
+ port = of_alias_get_id(np, "serial");
+ if (port < 0) {
+ dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port);
+ return port;
+ }
+ tup->uport.line = port;
+
+ tup->enable_modem_interrupt = of_property_read_bool(np,
+ "nvidia,enable-modem-interrupt");
+ return 0;
+}
+
+struct tegra_uart_chip_data tegra20_uart_chip_data = {
+ .tx_fifo_full_status = false,
+ .allow_txfifo_reset_fifo_mode = true,
+ .support_clk_src_div = false,
+};
+
+struct tegra_uart_chip_data tegra30_uart_chip_data = {
+ .tx_fifo_full_status = true,
+ .allow_txfifo_reset_fifo_mode = false,
+ .support_clk_src_div = true,
+};
+
+static struct of_device_id tegra_uart_of_match[] = {
+ {
+ .compatible = "nvidia,tegra30-hsuart",
+ .data = &tegra30_uart_chip_data,
+ }, {
+ .compatible = "nvidia,tegra20-hsuart",
+ .data = &tegra20_uart_chip_data,
+ }, {
+ },
+};
+MODULE_DEVICE_TABLE(of, tegra_uart_of_match);
+
+static int tegra_uart_probe(struct platform_device *pdev)
+{
+ struct tegra_uart_port *tup;
+ struct uart_port *u;
+ struct tegra_uart_platform_data *pdata = pdev->dev.platform_data;
+ struct resource *resource;
+ int ret;
+ const struct tegra_uart_chip_data *cdata;
+ const struct of_device_id *match;
+
+ match = of_match_device(of_match_ptr(tegra_uart_of_match),
+ &pdev->dev);
+ if (!match) {
+ dev_err(&pdev->dev, "Error: No device match found\n");
+ return -ENODEV;
+ }
+ cdata = match->data;
+
+ tup = devm_kzalloc(&pdev->dev, sizeof(*tup), GFP_KERNEL);
+ if (!tup) {
+ dev_err(&pdev->dev, "Failed to allocate memory for tup\n");
+ return -ENOMEM;
+ }
+
+ if (pdata) {
+ tup->uport.line = pdev->id;
+ tup->dma_req_sel = pdata->dma_req_sel;
+ tup->enable_modem_interrupt = pdata->enable_modem_interrupt;
+ } else {
+ ret = tegra_uart_parse_dt(pdev, tup);
+ if (ret < 0)
+ return ret;
+ }
+
+ u = &tup->uport;
+ u->dev = &pdev->dev;
+ u->ops = &tegra_uart_ops;
+ u->type = PORT_TEGRA;
+ u->fifosize = 32;
+ tup->cdata = cdata;
+
+ platform_set_drvdata(pdev, tup);
+ resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!resource) {
+ dev_err(&pdev->dev, "No IO memory resource\n");
+ return -ENODEV;
+ }
+
+ u->mapbase = resource->start;
+ u->membase = devm_request_and_ioremap(&pdev->dev, resource);
+ if (!u->membase) {
+ dev_err(&pdev->dev, "memregion/iomap address req failed\n");
+ return -EADDRNOTAVAIL;
+ }
+
+ tup->uart_clk = devm_clk_get(&pdev->dev, "uart-clk");
+ if (IS_ERR(tup->uart_clk)) {
+ dev_err(&pdev->dev, "Couldn't get the clock\n");
+ return PTR_ERR(tup->uart_clk);
+ }
+
+ u->iotype = UPIO_MEM32;
+ u->irq = platform_get_irq(pdev, 0);
+ u->regshift = 2;
+ ret = uart_add_one_port(&tegra_uart_driver, u);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret);
+ return ret;
+ }
+ return ret;
+}
+
+static int tegra_uart_remove(struct platform_device *pdev)
+{
+ struct tegra_uart_port *tup = platform_get_drvdata(pdev);
+ struct uart_port *u = &tup->uport;
+
+ uart_remove_one_port(&tegra_uart_driver, u);
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra_uart_suspend(struct device *dev)
+{
+ struct tegra_uart_port *tup = dev_get_drvdata(dev);
+ struct uart_port *u = &tup->uport;
+
+ return uart_suspend_port(&tegra_uart_driver, u);
+}
+
+static int tegra_uart_resume(struct device *dev)
+{
+ struct tegra_uart_port *tup = dev_get_drvdata(dev);
+ struct uart_port *u = &tup->uport;
+
+ return uart_resume_port(&tegra_uart_driver, u);
+}
+#endif
+
+static const struct dev_pm_ops tegra_uart_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(tegra_uart_suspend, tegra_uart_resume)
+};
+
+static struct platform_driver tegra_uart_platform_driver = {
+ .probe = tegra_uart_probe,
+ .remove = tegra_uart_remove,
+ .driver = {
+ .name = "serial-tegra",
+ .of_match_table = of_match_ptr(tegra_uart_of_match),
+ .pm = &tegra_uart_pm_ops,
+ },
+};
+
+static int __init tegra_uart_init(void)
+{
+ int ret;
+
+ ret = uart_register_driver(&tegra_uart_driver);
+ if (ret < 0) {
+ pr_err("Could not register %s driver\n",
+ tegra_uart_driver.driver_name);
+ return ret;
+ }
+
+ ret = platform_driver_register(&tegra_uart_platform_driver);
+ if (ret < 0) {
+ pr_err("Uart platfrom driver register failed, e = %d\n", ret);
+ uart_unregister_driver(&tegra_uart_driver);
+ return ret;
+ }
+ return 0;
+}
+
+static void __exit tegra_uart_exit(void)
+{
+ pr_info("Unloading tegra uart driver\n");
+ platform_driver_unregister(&tegra_uart_platform_driver);
+ uart_unregister_driver(&tegra_uart_driver);
+}
+
+module_init(tegra_uart_init);
+module_exit(tegra_uart_exit);
+
+MODULE_ALIAS("platform:serial-tegra");
+MODULE_DESCRIPTION("High speed UART driver for tegra chipset");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@xxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/platform_data/serial-tegra.h b/include/linux/platform_data/serial-tegra.h
new file mode 100644
index 0000000..d792986
--- /dev/null
+++ b/include/linux/platform_data/serial-tegra.h
@@ -0,0 +1,36 @@
+/*
+ * serial_tegra.h
+ *
+ * Interface for High-speed serial driver for NVIDIA Tegra SoCs.
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ *
+ * Author: Laxman Dewangan <ldewangan@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _SERIAL_TEGRA_H_
+#define _SERIAL_TEGRA_H_
+
+/**
+ * struct tegra_uart_platform_data: Platform data for tegra serial driver.
+ * @dma_req_sel: DMA requestor slave id.
+ * @enable_modem_interrupt: enable modem interrupt or not.
+ */
+struct tegra_uart_platform_data {
+ bool enable_modem_interrupt;
+ int dma_req_sel;
+};
+
+#endif /* _SERIAL_TEGRA_H_ */
--
1.7.1.1
--
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