serial: sirf: provide pm entries of uart_ops

this patch provides PM entry of uart_ops, then drop clk enable and
disable because serial core will do it.

the patch also fixes the issue that uart hang in resume caused by
not-enabled clock.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 11 insertions, 3 deletions

diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c
index 6fea79b96bb9..a6c38ab1eeb2 100644
--- a/drivers/tty/serial/sirfsoc_uart.c
+++ b/drivers/tty/serial/sirfsoc_uart.c
@@ -1033,6 +1033,16 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
         spin_unlock_irqrestore(&port->lock, flags);
 }
 
+static void sirfsoc_uart_pm(struct uart_port *port, unsigned int state,
+                              unsigned int oldstate)
+{
+        struct sirfsoc_uart_port *sirfport = to_sirfport(port);
+        if (!state)
+                clk_prepare_enable(sirfport->clk);
+        else
+                clk_disable_unprepare(sirfport->clk);
+}
+
 static unsigned int sirfsoc_uart_init_tx_dma(struct uart_port *port)
 {
         struct sirfsoc_uart_port *sirfport = to_sirfport(port);
@@ -1264,6 +1274,7 @@ static struct uart_ops sirfsoc_uart_ops = {
         .startup        = sirfsoc_uart_startup,
         .shutdown       = sirfsoc_uart_shutdown,
         .set_termios    = sirfsoc_uart_set_termios,
+        .pm             = sirfsoc_uart_pm,
         .type           = sirfsoc_uart_type,
         .release_port   = sirfsoc_uart_release_port,
         .request_port   = sirfsoc_uart_request_port,
@@ -1486,7 +1497,6 @@ usp_no_flow_control:
                 ret = PTR_ERR(sirfport->clk);
                 goto err;
         }
-        clk_prepare_enable(sirfport->clk);
         port->uartclk = clk_get_rate(sirfport->clk);
 
         port->ops = &sirfsoc_uart_ops;
@@ -1502,7 +1512,6 @@ usp_no_flow_control:
         return 0;
 
 port_err:
-        clk_disable_unprepare(sirfport->clk);
         clk_put(sirfport->clk);
 err:
         return ret;
@@ -1512,7 +1521,6 @@ static int sirfsoc_uart_remove(struct platform_device *pdev)
 {
         struct sirfsoc_uart_port *sirfport = platform_get_drvdata(pdev);
         struct uart_port *port = &sirfport->port;
-        clk_disable_unprepare(sirfport->clk);
         clk_put(sirfport->clk);
         uart_remove_one_port(&sirfsoc_uart_drv, port);
         return 0;