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.
Changes from V3:
- Dropped support for platform data and hence remove header file.
- In clk_get, pass NULL for connection name.
Resending patch as V4 version was sent before long holiday (19 dec) and
in the case of if it is missed. Just change the copyright year for this
resend to have 2013.
.../bindings/serial/nvidia,tegra20-hsuart.txt | 24 +
drivers/tty/serial/Kconfig | 11 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/serial-tegra.c | 1399 ++++++++++++++++++++
4 files changed, 1435 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt
create mode 100644 drivers/tty/serial/serial-tegra.c
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..ad094d2
--- /dev/null
+++ b/drivers/tty/serial/serial-tegra.c
@@ -0,0 +1,1399 @@
+/*
+ * serial_tegra.c
+ *
+ * High-speed serial driver for NVIDIA Tegra SoCs
+ *
+ * Copyright (c) 2012-2013, 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/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 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;
+ }
+
+ 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, NULL);
+ 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");
--
1.7.1.1
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