serial: sirf: only use lookup table to set baudrate when ioclk=150MHz

The fast lookup table to set baudrate is only right when ioclk
is 150MHz. for most platforms, ioclk is 150MHz, but some boards
might set ioclk to other frequency.

so re-calc the clk_div_reg when ioclk is not 150MHz. this patch
also gets clk in probe and puts it in remove.

Signed-off-by: Barry Song <Baohua.Song@csr.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 22 insertions, 7 deletions

diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c
index 8f3d6c091acc..6bbfe9934a4d 100644
--- a/drivers/tty/serial/sirfsoc_uart.c
+++ b/drivers/tty/serial/sirfsoc_uart.c
@@ -357,7 +357,6 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
                                        struct ktermios *old)
 {
         struct sirfsoc_uart_port *sirfport = to_sirfport(port);
-        unsigned long   ioclk_rate;
         unsigned long   config_reg = 0;
         unsigned long   baud_rate;
         unsigned long   setted_baud;
@@ -369,7 +368,6 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
         int             threshold_div;
         int             temp;
 
-        ioclk_rate = 150000000;
         switch (termios->c_cflag & CSIZE) {
         default:
         case CS8:
@@ -425,14 +423,17 @@ static void sirfsoc_uart_set_termios(struct uart_port *port,
                         sirfsoc_uart_disable_ms(port);
         }
 
-        /* common rate: fast calculation */
-        for (ic = 0; ic < SIRF_BAUD_RATE_SUPPORT_NR; ic++)
-                if (baud_rate == baudrate_to_regv[ic].baud_rate)
-                        clk_div_reg = baudrate_to_regv[ic].reg_val;
+        if (port->uartclk == 150000000) {
+                /* common rate: fast calculation */
+                for (ic = 0; ic < SIRF_BAUD_RATE_SUPPORT_NR; ic++)
+                        if (baud_rate == baudrate_to_regv[ic].baud_rate)
+                                clk_div_reg = baudrate_to_regv[ic].reg_val;
+        }
+
         setted_baud = baud_rate;
         /* arbitary rate setting */
         if (unlikely(clk_div_reg == 0))
-                clk_div_reg = sirfsoc_calc_sample_div(baud_rate, ioclk_rate,
+                clk_div_reg = sirfsoc_calc_sample_div(baud_rate, port->uartclk,
                                                                 &setted_baud);
         wr_regl(port, SIRFUART_DIVISOR, clk_div_reg);
 
@@ -691,6 +692,14 @@ int sirfsoc_uart_probe(struct platform_device *pdev)
                         goto err;
         }
 
+        sirfport->clk = clk_get(&pdev->dev, NULL);
+        if (IS_ERR(sirfport->clk)) {
+                ret = PTR_ERR(sirfport->clk);
+                goto clk_err;
+        }
+        clk_prepare_enable(sirfport->clk);
+        port->uartclk = clk_get_rate(sirfport->clk);
+
         port->ops = &sirfsoc_uart_ops;
         spin_lock_init(&port->lock);
 
@@ -704,6 +713,9 @@ int sirfsoc_uart_probe(struct platform_device *pdev)
         return 0;
 
 port_err:
+        clk_disable_unprepare(sirfport->clk);
+        clk_put(sirfport->clk);
+clk_err:
         platform_set_drvdata(pdev, NULL);
         if (sirfport->hw_flow_ctrl)
                 pinctrl_put(sirfport->p);
@@ -718,6 +730,8 @@ static int sirfsoc_uart_remove(struct platform_device *pdev)
         platform_set_drvdata(pdev, NULL);
         if (sirfport->hw_flow_ctrl)
                 pinctrl_put(sirfport->p);
+        clk_disable_unprepare(sirfport->clk);
+        clk_put(sirfport->clk);
         uart_remove_one_port(&sirfsoc_uart_drv, port);
         return 0;
 }
diff --git a/drivers/tty/serial/sirfsoc_uart.h b/drivers/tty/serial/sirfsoc_uart.h
index 6431640c3163..85328ba0c4e3 100644
--- a/drivers/tty/serial/sirfsoc_uart.h
+++ b/drivers/tty/serial/sirfsoc_uart.h
@@ -163,6 +163,7 @@ struct sirfsoc_uart_port {
 
         struct uart_port                port;
         struct pinctrl                  *p;
+        struct clk                      *clk;
 };
 
 /* Hardware Flow Control */