static irqreturn_t efm32_uart_rxirq(int irq, void *data)
{
struct efm32_uart_port *efm_port = data;
u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
int handled = IRQ_NONE;
struct uart_port *port = &efm_port->port;
struct tty_port *tport = &port->state->port;
spin_lock(&port->lock);
if (irqflag & UARTn_IF_RXDATAV) {
efm32_uart_write32(efm_port, UARTn_IF_RXDATAV, UARTn_IFC);
efm32_uart_rx_chars(efm_port);
handled = IRQ_HANDLED;
}
if (irqflag & UARTn_IF_RXOF) {
efm32_uart_write32(efm_port, UARTn_IF_RXOF, UARTn_IFC);
port->icount.overrun++;
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
handled = IRQ_HANDLED;
}
spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
return handled;
}
static void efm32_uart_tx_chars(struct efm32_uart_port *efm_port)
{
struct uart_port *port = &efm_port->port;
struct circ_buf *xmit = &port->state->xmit;
while (efm32_uart_read32(efm_port, UARTn_STATUS) &
UARTn_STATUS_TXBL) {
if (port->x_char) {
port->icount.tx++;
efm32_uart_write32(efm_port, port->x_char,
UARTn_TXDATA);
port->x_char = 0;
continue;
}
if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
port->icount.tx++;
efm32_uart_write32(efm_port, xmit->buf[xmit->tail],
UARTn_TXDATA);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
} else
break;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (!port->x_char && uart_circ_empty(xmit) &&
efm32_uart_read32(efm_port, UARTn_STATUS) &
UARTn_STATUS_TXC)
efm32_uart_stop_tx(port);
}
static void efm32_uart_stop_tx(struct uart_port *port)
{
struct efm32_uart_port *efm_port = to_efm_port(port);
u32 ien = efm32_uart_read32(efm_port, UARTn_IEN);
efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD);
ien &= ~(UARTn_IF_TXC | UARTn_IF_TXBL);
efm32_uart_write32(efm_port, ien, UARTn_IEN);
}
static void efm32_uart_start_tx(struct uart_port *port)
{
struct efm32_uart_port *efm_port = to_efm_port(port);
u32 ien;
efm32_uart_write32(efm_port,
UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IFC);
ien = efm32_uart_read32(efm_port, UARTn_IEN);
efm32_uart_write32(efm_port,
ien | UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IEN);
efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD);
efm32_uart_tx_chars(efm_port);
}
static int efm32_uart_startup(struct uart_port *port)
{
struct efm32_uart_port *efm_port = to_efm_port(port);
u32 location = 0;
struct efm32_uart_pdata *pdata = dev_get_platdata(port->dev);
int ret;
if (pdata)
location = UARTn_ROUTE_LOCATION(pdata->location);
ret = clk_enable(efm_port->clk);
if (ret) {
efm_debug(efm_port, "failed to enable clk\n");
goto err_clk_enable;
}
port->uartclk = clk_get_rate(efm_port->clk);
/* Enable pins at configured location */
efm32_uart_write32(efm_port, location | UARTn_ROUTE_RXPEN | UARTn_ROUTE_TXPEN,
UARTn_ROUTE);
ret = request_irq(port->irq, efm32_uart_rxirq, 0,
DRIVER_NAME, efm_port);
if (ret) {
efm_debug(efm_port, "failed to register rxirq\n");
goto err_request_irq_rx;
}
/* disable all irqs */
efm32_uart_write32(efm_port, 0, UARTn_IEN);
ret = request_irq(efm_port->txirq, efm32_uart_txirq, 0,
DRIVER_NAME, efm_port);
if (ret) {
efm_debug(efm_port, "failed to register txirq\n");
free_irq(port->irq, efm_port);
err_request_irq_rx:
clk_disable(efm_port->clk);
} else {
efm32_uart_write32(efm_port,
UARTn_IF_RXDATAV | UARTn_IF_RXOF, UARTn_IEN);
efm32_uart_write32(efm_port, UARTn_CMD_RXEN, UARTn_CMD);
}
err_clk_enable:
return ret;
}
static void efm32_uart_shutdown(struct uart_port *port)
{
struct efm32_uart_port *efm_port = to_efm_port(port);
efm32_uart_write32(efm_port, 0, UARTn_IEN);
free_irq(port->irq, efm_port);
clk_disable(efm_port->clk);
}
static irqreturn_t efm32_uart_txirq(int irq, void *data)
{
struct efm32_uart_port *efm_port = data;
u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
/* TXBL doesn't need to be cleared */
if (irqflag & UARTn_IF_TXC)
efm32_uart_write32(efm_port, UARTn_IF_TXC, UARTn_IFC);
if (irqflag & (UARTn_IF_TXC | UARTn_IF_TXBL)) {
efm32_uart_tx_chars(efm_port);
return IRQ_HANDLED;
} else
return IRQ_NONE;
}
static void efm32_uart_stop_rx(struct uart_port *port)
{
struct efm32_uart_port *efm_port = to_efm_port(port);
efm32_uart_write32(efm_port, UARTn_CMD_RXDIS, UARTn_CMD);
}