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path: root/drivers/tty/serial/8250/8250_dw.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_dw.c')
-rw-r--r--drivers/tty/serial/8250/8250_dw.c76
1 files changed, 57 insertions, 19 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index daf710f5c3fc..4658e3e0ec42 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -56,11 +56,11 @@
struct dw8250_data {
- int last_lcr;
- int last_mcr;
- int line;
- struct clk *clk;
- u8 usr_reg;
+ u8 usr_reg;
+ int last_mcr;
+ int line;
+ struct clk *clk;
+ struct uart_8250_dma dma;
};
static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
@@ -76,17 +76,33 @@ static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
return value;
}
+static void dw8250_force_idle(struct uart_port *p)
+{
+ serial8250_clear_and_reinit_fifos(container_of
+ (p, struct uart_8250_port, port));
+ (void)p->serial_in(p, UART_RX);
+}
+
static void dw8250_serial_out(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = p->private_data;
- if (offset == UART_LCR)
- d->last_lcr = value;
-
if (offset == UART_MCR)
d->last_mcr = value;
writeb(value, p->membase + (offset << p->regshift));
+
+ /* Make sure LCR write wasn't ignored */
+ if (offset == UART_LCR) {
+ int tries = 1000;
+ while (tries--) {
+ if (value == p->serial_in(p, UART_LCR))
+ return;
+ dw8250_force_idle(p);
+ writeb(value, p->membase + (UART_LCR << p->regshift));
+ }
+ dev_err(p->dev, "Couldn't set LCR to %d\n", value);
+ }
}
static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
@@ -107,13 +123,22 @@ static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = p->private_data;
- if (offset == UART_LCR)
- d->last_lcr = value;
-
if (offset == UART_MCR)
d->last_mcr = value;
writel(value, p->membase + (offset << p->regshift));
+
+ /* Make sure LCR write wasn't ignored */
+ if (offset == UART_LCR) {
+ int tries = 1000;
+ while (tries--) {
+ if (value == p->serial_in(p, UART_LCR))
+ return;
+ dw8250_force_idle(p);
+ writel(value, p->membase + (UART_LCR << p->regshift));
+ }
+ dev_err(p->dev, "Couldn't set LCR to %d\n", value);
+ }
}
static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
@@ -131,9 +156,8 @@ static int dw8250_handle_irq(struct uart_port *p)
if (serial8250_handle_irq(p, iir)) {
return 1;
} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
- /* Clear the USR and write the LCR again. */
+ /* Clear the USR */
(void)p->serial_in(p, d->usr_reg);
- p->serial_out(p, UART_LCR, d->last_lcr);
return 1;
}
@@ -153,6 +177,14 @@ dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
pm_runtime_put_sync_suspend(port->dev);
}
+static bool dw8250_dma_filter(struct dma_chan *chan, void *param)
+{
+ struct dw8250_data *data = param;
+
+ return chan->chan_id == data->dma.tx_chan_id ||
+ chan->chan_id == data->dma.rx_chan_id;
+}
+
static void dw8250_setup_port(struct uart_8250_port *up)
{
struct uart_port *p = &up->port;
@@ -241,7 +273,8 @@ static int dw8250_probe_of(struct uart_port *p,
}
#ifdef CONFIG_ACPI
-static int dw8250_probe_acpi(struct uart_8250_port *up)
+static int dw8250_probe_acpi(struct uart_8250_port *up,
+ struct dw8250_data *data)
{
const struct acpi_device_id *id;
struct uart_port *p = &up->port;
@@ -260,9 +293,7 @@ static int dw8250_probe_acpi(struct uart_8250_port *up)
if (!p->uartclk)
p->uartclk = (unsigned int)id->driver_data;
- up->dma = devm_kzalloc(p->dev, sizeof(*up->dma), GFP_KERNEL);
- if (!up->dma)
- return -ENOMEM;
+ up->dma = &data->dma;
up->dma->rxconf.src_maxburst = p->fifosize / 4;
up->dma->txconf.dst_maxburst = p->fifosize / 4;
@@ -270,7 +301,8 @@ static int dw8250_probe_acpi(struct uart_8250_port *up)
return 0;
}
#else
-static inline int dw8250_probe_acpi(struct uart_8250_port *up)
+static inline int dw8250_probe_acpi(struct uart_8250_port *up,
+ struct dw8250_data *data)
{
return -ENODEV;
}
@@ -314,6 +346,12 @@ static int dw8250_probe(struct platform_device *pdev)
uart.port.uartclk = clk_get_rate(data->clk);
}
+ data->dma.rx_chan_id = -1;
+ data->dma.tx_chan_id = -1;
+ data->dma.rx_param = data;
+ data->dma.tx_param = data;
+ data->dma.fn = dw8250_dma_filter;
+
uart.port.iotype = UPIO_MEM;
uart.port.serial_in = dw8250_serial_in;
uart.port.serial_out = dw8250_serial_out;
@@ -324,7 +362,7 @@ static int dw8250_probe(struct platform_device *pdev)
if (err)
return err;
} else if (ACPI_HANDLE(&pdev->dev)) {
- err = dw8250_probe_acpi(&uart);
+ err = dw8250_probe_acpi(&uart, data);
if (err)
return err;
} else {