diff options
Diffstat (limited to 'drivers/tty/serial/meson_uart.c')
| -rw-r--r-- | drivers/tty/serial/meson_uart.c | 80 |
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; |