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path: root/drivers/tty/serial/meson_uart.c
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Diffstat (limited to 'drivers/tty/serial/meson_uart.c')
-rw-r--r--drivers/tty/serial/meson_uart.c80
1 files changed, 63 insertions, 17 deletions
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 0fc83c962..b12a37bd3 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -57,6 +57,7 @@
#define AML_UART_RX_EMPTY BIT(20)
#define AML_UART_TX_FULL BIT(21)
#define AML_UART_TX_EMPTY BIT(22)
+#define AML_UART_XMIT_BUSY BIT(25)
#define AML_UART_ERR (AML_UART_PARITY_ERR | \
AML_UART_FRAME_ERR | \
AML_UART_TX_FIFO_WERR)
@@ -100,7 +101,8 @@ static unsigned int meson_uart_tx_empty(struct uart_port *port)
u32 val;
val = readl(port->membase + AML_UART_STATUS);
- return (val & AML_UART_TX_EMPTY) ? TIOCSER_TEMT : 0;
+ val &= (AML_UART_TX_EMPTY | AML_UART_XMIT_BUSY);
+ return (val == AML_UART_TX_EMPTY) ? TIOCSER_TEMT : 0;
}
static void meson_uart_stop_tx(struct uart_port *port)
@@ -108,7 +110,7 @@ static void meson_uart_stop_tx(struct uart_port *port)
u32 val;
val = readl(port->membase + AML_UART_CONTROL);
- val &= ~AML_UART_TX_EN;
+ val &= ~AML_UART_TX_INT_EN;
writel(val, port->membase + AML_UART_CONTROL);
}
@@ -131,7 +133,7 @@ static void meson_uart_shutdown(struct uart_port *port)
spin_lock_irqsave(&port->lock, flags);
val = readl(port->membase + AML_UART_CONTROL);
- val &= ~(AML_UART_RX_EN | AML_UART_TX_EN);
+ val &= ~AML_UART_RX_EN;
val &= ~(AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
writel(val, port->membase + AML_UART_CONTROL);
@@ -142,6 +144,7 @@ static void meson_uart_start_tx(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
unsigned int ch;
+ u32 val;
if (uart_tx_stopped(port)) {
meson_uart_stop_tx(port);
@@ -165,6 +168,12 @@ static void meson_uart_start_tx(struct uart_port *port)
port->icount.tx++;
}
+ if (!uart_circ_empty(xmit)) {
+ val = readl(port->membase + AML_UART_CONTROL);
+ val |= AML_UART_TX_INT_EN;
+ writel(val, port->membase + AML_UART_CONTROL);
+ }
+
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
}
@@ -228,8 +237,10 @@ static irqreturn_t meson_uart_interrupt(int irq, void *dev_id)
if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY))
meson_receive_chars(port);
- if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL))
- meson_uart_start_tx(port);
+ if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_FULL)) {
+ if (readl(port->membase + AML_UART_CONTROL) & AML_UART_TX_INT_EN)
+ meson_uart_start_tx(port);
+ }
spin_unlock(&port->lock);
@@ -241,10 +252,9 @@ static const char *meson_uart_type(struct uart_port *port)
return (port->type == PORT_MESON) ? "meson_uart" : NULL;
}
-static int meson_uart_startup(struct uart_port *port)
+static void meson_uart_reset(struct uart_port *port)
{
u32 val;
- int ret = 0;
val = readl(port->membase + AML_UART_CONTROL);
val |= (AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
@@ -252,6 +262,18 @@ static int meson_uart_startup(struct uart_port *port)
val &= ~(AML_UART_RX_RST | AML_UART_TX_RST | AML_UART_CLR_ERR);
writel(val, port->membase + AML_UART_CONTROL);
+}
+
+static int meson_uart_startup(struct uart_port *port)
+{
+ u32 val;
+ int ret = 0;
+
+ val = readl(port->membase + AML_UART_CONTROL);
+ val |= AML_UART_CLR_ERR;
+ writel(val, port->membase + AML_UART_CONTROL);
+ val &= ~AML_UART_CLR_ERR;
+ writel(val, port->membase + AML_UART_CONTROL);
val |= (AML_UART_RX_EN | AML_UART_TX_EN);
writel(val, port->membase + AML_UART_CONTROL);
@@ -272,7 +294,7 @@ static void meson_uart_change_speed(struct uart_port *port, unsigned long baud)
{
u32 val;
- while (!(readl(port->membase + AML_UART_STATUS) & AML_UART_TX_EMPTY))
+ while (!meson_uart_tx_empty(port))
cpu_relax();
val = readl(port->membase + AML_UART_REG5);
@@ -367,9 +389,26 @@ static int meson_uart_verify_port(struct uart_port *port,
return ret;
}
+static int meson_uart_res_size(struct uart_port *port)
+{
+ struct platform_device *pdev = to_platform_device(port->dev);
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(port->dev, "cannot obtain I/O memory region");
+ return -ENODEV;
+ }
+
+ return resource_size(res);
+}
+
static void meson_uart_release_port(struct uart_port *port)
{
+ int size = meson_uart_res_size(port);
+
if (port->flags & UPF_IOREMAP) {
+ devm_release_mem_region(port->dev, port->mapbase, size);
devm_iounmap(port->dev, port->membase);
port->membase = NULL;
}
@@ -377,16 +416,10 @@ static void meson_uart_release_port(struct uart_port *port)
static int meson_uart_request_port(struct uart_port *port)
{
- struct platform_device *pdev = to_platform_device(port->dev);
- struct resource *res;
- int size;
+ int size = meson_uart_res_size(port);
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev, "cannot obtain I/O memory region");
- return -ENODEV;
- }
- size = resource_size(res);
+ if (size < 0)
+ return size;
if (!devm_request_mem_region(port->dev, port->mapbase, size,
dev_name(port->dev))) {
@@ -448,6 +481,7 @@ static void meson_serial_console_write(struct console *co, const char *s,
struct uart_port *port;
unsigned long flags;
int locked;
+ u32 val, tmp;
port = meson_ports[co->index];
if (!port)
@@ -463,7 +497,13 @@ static void meson_serial_console_write(struct console *co, const char *s,
locked = 1;
}
+ val = readl(port->membase + AML_UART_CONTROL);
+ val |= AML_UART_TX_EN;
+ tmp = val & ~(AML_UART_TX_INT_EN | AML_UART_RX_INT_EN);
+ writel(tmp, port->membase + AML_UART_CONTROL);
+
uart_console_write(port, s, count, meson_console_putchar);
+ writel(val, port->membase + AML_UART_CONTROL);
if (locked)
spin_unlock(&port->lock);
@@ -570,6 +610,12 @@ static int meson_uart_probe(struct platform_device *pdev)
meson_ports[pdev->id] = port;
platform_set_drvdata(pdev, port);
+ /* reset port before registering (and possibly registering console) */
+ if (meson_uart_request_port(port) >= 0) {
+ meson_uart_reset(port);
+ meson_uart_release_port(port);
+ }
+
ret = uart_add_one_port(&meson_uart_driver, port);
if (ret)
meson_ports[pdev->id] = NULL;