On 13. 12. 21, 8:10, Hammer Hsieh wrote:
Add Sunplus SoC UART Driver
Signed-off-by: Hammer Hsieh <hammer.hsieh@xxxxxxxxxxx>
...
--- /dev/null
+++ b/drivers/tty/serial/sunplus-uart.c
...
+static void receive_chars(struct uart_port *port)
+{
+ unsigned int lsr = readl(port->membase + SUP_UART_LSR);
+ unsigned int ch, flag;
+
+ do {
+ ch = readl(port->membase + SUP_UART_DATA);
+ flag = TTY_NORMAL;
+ port->icount.rx++;
+
+ if (unlikely(lsr & SUP_UART_LSR_BRK_ERROR_BITS)) {
+ if (lsr & SUP_UART_LSR_BC) {
+ lsr &= ~(SUP_UART_LSR_FE | SUP_UART_LSR_PE);
+ port->icount.brk++;
+ if (uart_handle_break(port))
+ goto ignore_char;
+ } else if (lsr & SUP_UART_LSR_PE) {
+ port->icount.parity++;
+ } else if (lsr & SUP_UART_LSR_FE) {
+ port->icount.frame++;
+ }
+
+ if (lsr & SUP_UART_LSR_OE)
+ port->icount.overrun++;
+
+ if (lsr & SUP_UART_LSR_BC)
+ flag = TTY_BREAK;
+ else if (lsr & SUP_UART_LSR_PE)
+ flag = TTY_PARITY;
+ else if (lsr & SUP_UART_LSR_FE)
+ flag = TTY_FRAME;
Why do you handle these separately and not above?
+ }
+
+ if (port->ignore_status_mask & SUP_DUMMY_READ)
+ goto ignore_char;
+
+ if (uart_handle_sysrq_char(port, ch))
+ goto ignore_char;
+
+ uart_insert_char(port, lsr, SUP_UART_LSR_OE, ch, flag);
+
+ignore_char:
+ lsr = readl(port->membase + SUP_UART_LSR);
+ } while (lsr & SUP_UART_LSR_RX);
+
+ tty_flip_buffer_push(&port->state->port);
+}
+
+static irqreturn_t sunplus_uart_irq(int irq, void *args)
+{
+ struct uart_port *port = (struct uart_port *)args;
No need to cast here.
+ unsigned int isc = readl(port->membase + SUP_UART_ISC);
Shouldn't this be under the spinlock?
And "if (!isc) return IRQ_NONE"?
+ spin_lock(&port->lock);
+
+ if (isc & SUP_UART_ISC_RX)
+ receive_chars(port);
+
+ if (isc & SUP_UART_ISC_TX)
+ transmit_chars(port);
+
+ spin_unlock(&port->lock);
+
+ return IRQ_HANDLED;
+}
+
+static int sunplus_startup(struct uart_port *port)
+{
+ unsigned long flags;
+ unsigned int isc;
+ int ret;
+
+ ret = request_irq(port->irq, sunplus_uart_irq, 0, "sunplus_uart", port);
Cannot the interrupt be shared?
+ if (ret)
+ return ret;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ isc |= SUP_UART_ISC_RXM;
+ writel(isc, port->membase + SUP_UART_ISC);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return 0;
+}
+
+static void sunplus_shutdown(struct uart_port *port)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ writel(0, port->membase + SUP_UART_ISC);
What bus is this -- posting?
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ free_irq(port->irq, port);
+}
...
+static void sunplus_release_port(struct uart_port *port)
+{
+}
+
+static int sunplus_request_port(struct uart_port *port)
+{
+ return 0;
+}
These two are optional -- no need to provide them.
regards,
--
js
suse labs
