Commit 85b5c1dd authored by Long Cheng's avatar Long Cheng Committed by Greg Kroah-Hartman

serial: 8250-mtk: add uart DMA support

Modify uart register to support DMA function.
Signed-off-by: default avatarLong Cheng <long.cheng@mediatek.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 89212465
...@@ -14,6 +14,10 @@ ...@@ -14,6 +14,10 @@
#include <linux/pm_runtime.h> #include <linux/pm_runtime.h>
#include <linux/serial_8250.h> #include <linux/serial_8250.h>
#include <linux/serial_reg.h> #include <linux/serial_reg.h>
#include <linux/console.h>
#include <linux/dma-mapping.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include "8250.h" #include "8250.h"
...@@ -22,12 +26,172 @@ ...@@ -22,12 +26,172 @@
#define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */ #define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */
#define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */ #define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */
#define MTK_UART_DMA_EN 0x13 /* DMA Enable register */
#define MTK_UART_DMA_EN_TX 0x2
#define MTK_UART_DMA_EN_RX 0x5
#define MTK_UART_TX_SIZE UART_XMIT_SIZE
#define MTK_UART_RX_SIZE 0x8000
#define MTK_UART_TX_TRIGGER 1
#define MTK_UART_RX_TRIGGER MTK_UART_RX_SIZE
#ifdef CONFIG_SERIAL_8250_DMA
enum dma_rx_status {
DMA_RX_START = 0,
DMA_RX_RUNNING = 1,
DMA_RX_SHUTDOWN = 2,
};
#endif
struct mtk8250_data { struct mtk8250_data {
int line; int line;
unsigned int rx_pos;
struct clk *uart_clk; struct clk *uart_clk;
struct clk *bus_clk; struct clk *bus_clk;
struct uart_8250_dma *dma;
#ifdef CONFIG_SERIAL_8250_DMA
enum dma_rx_status rx_status;
#endif
}; };
#ifdef CONFIG_SERIAL_8250_DMA
static void mtk8250_rx_dma(struct uart_8250_port *up);
static void mtk8250_dma_rx_complete(void *param)
{
struct uart_8250_port *up = param;
struct uart_8250_dma *dma = up->dma;
struct mtk8250_data *data = up->port.private_data;
struct tty_port *tty_port = &up->port.state->port;
struct dma_tx_state state;
unsigned char *ptr;
int copied;
dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
dma->rx_size, DMA_FROM_DEVICE);
dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
if (data->rx_status == DMA_RX_SHUTDOWN)
return;
if ((data->rx_pos + state.residue) <= dma->rx_size) {
ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
copied = tty_insert_flip_string(tty_port, ptr, state.residue);
} else {
ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
copied = tty_insert_flip_string(tty_port, ptr,
dma->rx_size - data->rx_pos);
ptr = (unsigned char *)(dma->rx_buf);
copied += tty_insert_flip_string(tty_port, ptr,
data->rx_pos + state.residue - dma->rx_size);
}
up->port.icount.rx += copied;
tty_flip_buffer_push(tty_port);
mtk8250_rx_dma(up);
}
static void mtk8250_rx_dma(struct uart_8250_port *up)
{
struct uart_8250_dma *dma = up->dma;
struct mtk8250_data *data = up->port.private_data;
struct dma_async_tx_descriptor *desc;
struct dma_tx_state state;
desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
dma->rx_size, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc) {
pr_err("failed to prepare rx slave single\n");
return;
}
desc->callback = mtk8250_dma_rx_complete;
desc->callback_param = up;
dma->rx_cookie = dmaengine_submit(desc);
dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
data->rx_pos = state.residue;
dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr,
dma->rx_size, DMA_FROM_DEVICE);
dma_async_issue_pending(dma->rxchan);
}
static void mtk8250_dma_enable(struct uart_8250_port *up)
{
struct uart_8250_dma *dma = up->dma;
struct mtk8250_data *data = up->port.private_data;
int lcr = serial_in(up, UART_LCR);
if (data->rx_status != DMA_RX_START)
return;
dma->rxconf.direction = DMA_DEV_TO_MEM;
dma->rxconf.src_addr_width = dma->rx_size / 1024;
dma->rxconf.src_addr = dma->rx_addr;
dma->txconf.direction = DMA_MEM_TO_DEV;
dma->txconf.dst_addr_width = MTK_UART_TX_SIZE / 1024;
dma->txconf.dst_addr = dma->tx_addr;
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT);
serial_out(up, MTK_UART_DMA_EN,
MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX);
serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
serial_out(up, UART_EFR, UART_EFR_ECB);
serial_out(up, UART_LCR, lcr);
if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0)
pr_err("failed to configure rx dma channel\n");
if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0)
pr_err("failed to configure tx dma channel\n");
data->rx_status = DMA_RX_RUNNING;
data->rx_pos = 0;
mtk8250_rx_dma(up);
}
#endif
static int mtk8250_startup(struct uart_port *port)
{
#ifdef CONFIG_SERIAL_8250_DMA
struct uart_8250_port *up = up_to_u8250p(port);
struct mtk8250_data *data = port->private_data;
/* disable DMA for console */
if (uart_console(port))
up->dma = NULL;
if (up->dma) {
data->rx_status = DMA_RX_START;
uart_circ_clear(&port->state->xmit);
}
#endif
memset(&port->icount, 0, sizeof(port->icount));
return serial8250_do_startup(port);
}
static void mtk8250_shutdown(struct uart_port *port)
{
#ifdef CONFIG_SERIAL_8250_DMA
struct uart_8250_port *up = up_to_u8250p(port);
struct mtk8250_data *data = port->private_data;
if (up->dma)
data->rx_status = DMA_RX_SHUTDOWN;
#endif
return serial8250_do_shutdown(port);
}
static void static void
mtk8250_set_termios(struct uart_port *port, struct ktermios *termios, mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old) struct ktermios *old)
...@@ -36,6 +200,17 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios, ...@@ -36,6 +200,17 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
unsigned long flags; unsigned long flags;
unsigned int baud, quot; unsigned int baud, quot;
#ifdef CONFIG_SERIAL_8250_DMA
if (up->dma) {
if (uart_console(port)) {
devm_kfree(up->port.dev, up->dma);
up->dma = NULL;
} else {
mtk8250_dma_enable(up);
}
}
#endif
serial8250_do_set_termios(port, termios, old); serial8250_do_set_termios(port, termios, old);
/* /*
...@@ -143,9 +318,20 @@ mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old) ...@@ -143,9 +318,20 @@ mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
pm_runtime_put_sync_suspend(port->dev); pm_runtime_put_sync_suspend(port->dev);
} }
#ifdef CONFIG_SERIAL_8250_DMA
static bool mtk8250_dma_filter(struct dma_chan *chan, void *param)
{
return false;
}
#endif
static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p, static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
struct mtk8250_data *data) struct mtk8250_data *data)
{ {
#ifdef CONFIG_SERIAL_8250_DMA
int dmacnt;
#endif
data->uart_clk = devm_clk_get(&pdev->dev, "baud"); data->uart_clk = devm_clk_get(&pdev->dev, "baud");
if (IS_ERR(data->uart_clk)) { if (IS_ERR(data->uart_clk)) {
/* /*
...@@ -162,7 +348,23 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p, ...@@ -162,7 +348,23 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
} }
data->bus_clk = devm_clk_get(&pdev->dev, "bus"); data->bus_clk = devm_clk_get(&pdev->dev, "bus");
return PTR_ERR_OR_ZERO(data->bus_clk); if (IS_ERR(data->bus_clk))
return PTR_ERR(data->bus_clk);
data->dma = NULL;
#ifdef CONFIG_SERIAL_8250_DMA
dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names");
if (dmacnt == 2) {
data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma),
GFP_KERNEL);
data->dma->fn = mtk8250_dma_filter;
data->dma->rx_size = MTK_UART_RX_SIZE;
data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER;
data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER;
}
#endif
return 0;
} }
static int mtk8250_probe(struct platform_device *pdev) static int mtk8250_probe(struct platform_device *pdev)
...@@ -204,8 +406,14 @@ static int mtk8250_probe(struct platform_device *pdev) ...@@ -204,8 +406,14 @@ static int mtk8250_probe(struct platform_device *pdev)
uart.port.iotype = UPIO_MEM32; uart.port.iotype = UPIO_MEM32;
uart.port.regshift = 2; uart.port.regshift = 2;
uart.port.private_data = data; uart.port.private_data = data;
uart.port.shutdown = mtk8250_shutdown;
uart.port.startup = mtk8250_startup;
uart.port.set_termios = mtk8250_set_termios; uart.port.set_termios = mtk8250_set_termios;
uart.port.uartclk = clk_get_rate(data->uart_clk); uart.port.uartclk = clk_get_rate(data->uart_clk);
#ifdef CONFIG_SERIAL_8250_DMA
if (data->dma)
uart.dma = data->dma;
#endif
/* Disable Rate Fix function */ /* Disable Rate Fix function */
writel(0x0, uart.port.membase + writel(0x0, uart.port.membase +
......
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