serial/amba-pl011: move custom pin control to driver

We had a boot regression in Ux500 in the merge window because
two orthogonal pin control schemes for the PL011 were merged
at the same time:

- One using the .init() and .exit() hooks into the platform
  for Ux500 putting the pins into default vs sleep state
  respectively as the port was started/stopped.
  commit a09806607fd20bed2f8c41fe22793386790a14aa
  "ARM: ux500: switch to using pinctrl for uart0"

- One hogging the default setting at PL011 probe()
  commit 258e055111d3cde2607e0d04eb91da2f7a59b591
  "serial: amba-pl011: adopt pinctrl support"

To get a solution that works for both let's scrap the stuff
in the platform callbacks, instead have the driver itself
select default and sleep states when the port is
started/stopped. Hopefully this works for all clients.
Platform callbacks are bad for device tree migration anyway,
so this rids us of another problem in Ux500.

Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Reported-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/mach-ux500/board-mop500.c b/arch/arm/mach-ux500/board-mop500.c
index 9c74ac5..1509a3c 100644 (file)
--- a/arch/arm/mach-ux500/board-mop500.c
+++ b/arch/arm/mach-ux500/board-mop500.c
@@ -580,43 +580,12 @@ static void ux500_uart0_reset(void)
        udelay(1);
 }
 
-/* This needs to be referenced by callbacks */
-struct pinctrl *u0_p;
-struct pinctrl_state *u0_def;
-struct pinctrl_state *u0_sleep;
-
-static void ux500_uart0_init(void)
-{
-       int ret;
-
-       if (IS_ERR(u0_p) || IS_ERR(u0_def))
-               return;
-
-       ret = pinctrl_select_state(u0_p, u0_def);
-       if (ret)
-               pr_err("could not set UART0 defstate\n");
-}
-
-static void ux500_uart0_exit(void)
-{
-       int ret;
-
-       if (IS_ERR(u0_p) || IS_ERR(u0_sleep))
-               return;
-
-       ret = pinctrl_select_state(u0_p, u0_sleep);
-       if (ret)
-               pr_err("could not set UART0 idlestate\n");
-}
-
 static struct amba_pl011_data uart0_plat = {
 #ifdef CONFIG_STE_DMA40
        .dma_filter = stedma40_filter,
        .dma_rx_param = &uart0_dma_cfg_rx,
        .dma_tx_param = &uart0_dma_cfg_tx,
 #endif
-       .init = ux500_uart0_init,
-       .exit = ux500_uart0_exit,
        .reset = ux500_uart0_reset,
 };
 
@@ -638,28 +607,7 @@ static struct amba_pl011_data uart2_plat = {
 
 static void __init mop500_uart_init(struct device *parent)
 {
-       struct amba_device *uart0_device;
-
-       uart0_device = db8500_add_uart0(parent, &uart0_plat);
-       if (uart0_device) {
-               u0_p = pinctrl_get(&uart0_device->dev);
-               if (IS_ERR(u0_p))
-                       dev_err(&uart0_device->dev,
-                               "could not get UART0 pinctrl\n");
-               else {
-                       u0_def = pinctrl_lookup_state(u0_p,
-                                                     PINCTRL_STATE_DEFAULT);
-                       if (IS_ERR(u0_def)) {
-                               dev_err(&uart0_device->dev,
-                                       "could not get UART0 defstate\n");
-                       }
-                       u0_sleep = pinctrl_lookup_state(u0_p,
-                                                       PINCTRL_STATE_SLEEP);
-                       if (IS_ERR(u0_sleep))
-                               dev_err(&uart0_device->dev,
-                                       "could not get UART0 idlestate\n");
-               }
-       }
+       db8500_add_uart0(parent, &uart0_plat);
        db8500_add_uart1(parent, &uart1_plat);
        db8500_add_uart2(parent, &uart2_plat);
 }

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 4ad721f..c17923e 100644 (file)
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -133,6 +133,10 @@ struct pl011_dmatx_data {
 struct uart_amba_port {
        struct uart_port        port;
        struct clk              *clk;
+       /* Two optional pin states - default & sleep */
+       struct pinctrl          *pinctrl;
+       struct pinctrl_state    *pins_default;
+       struct pinctrl_state    *pins_sleep;
        const struct vendor_data *vendor;
        unsigned int            dmacr;          /* dma control reg */
        unsigned int            im;             /* interrupt mask */
@@ -1312,6 +1316,14 @@ static int pl011_startup(struct uart_port *port)
        unsigned int cr;
        int retval;
 
+       /* Optionaly enable pins to be muxed in and configured */
+       if (!IS_ERR(uap->pins_default)) {
+               retval = pinctrl_select_state(uap->pinctrl, uap->pins_default);
+               if (retval)
+                       dev_err(port->dev,
+                               "could not set default pins\n");
+       }
+
        retval = clk_prepare(uap->clk);
        if (retval)
                goto out;
@@ -1420,6 +1432,7 @@ static void pl011_shutdown(struct uart_port *port)
 {
        struct uart_amba_port *uap = (struct uart_amba_port *)port;
        unsigned int cr;
+       int retval;
 
        /*
         * disable all interrupts
@@ -1462,6 +1475,14 @@ static void pl011_shutdown(struct uart_port *port)
         */
        clk_disable(uap->clk);
        clk_unprepare(uap->clk);
+       /* Optionally let pins go into sleep states */
+       if (!IS_ERR(uap->pins_sleep)) {
+               retval = pinctrl_select_state(uap->pinctrl, uap->pins_sleep);
+               if (retval)
+                       dev_err(port->dev,
+                               "could not set pins to sleep state\n");
+       }
+
 
        if (uap->port.dev->platform_data) {
                struct amba_pl011_data *plat;
@@ -1792,6 +1813,14 @@ static int __init pl011_console_setup(struct console *co, char *options)
        if (!uap)
                return -ENODEV;
 
+       /* Allow pins to be muxed in and configured */
+       if (!IS_ERR(uap->pins_default)) {
+               ret = pinctrl_select_state(uap->pinctrl, uap->pins_default);
+               if (ret)
+                       dev_err(uap->port.dev,
+                               "could not set default pins\n");
+       }
+
        ret = clk_prepare(uap->clk);
        if (ret)
                return ret;
@@ -1844,7 +1873,6 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 {
        struct uart_amba_port *uap;
        struct vendor_data *vendor = id->data;
-       struct pinctrl *pinctrl;
        void __iomem *base;
        int i, ret;
 
@@ -1869,11 +1897,20 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
                goto free;
        }
 
-       pinctrl = devm_pinctrl_get_select_default(&dev->dev);
-       if (IS_ERR(pinctrl)) {
-               ret = PTR_ERR(pinctrl);
+       uap->pinctrl = devm_pinctrl_get(&dev->dev);
+       if (IS_ERR(uap->pinctrl)) {
+               ret = PTR_ERR(uap->pinctrl);
                goto unmap;
        }
+       uap->pins_default = pinctrl_lookup_state(uap->pinctrl,
+                                                PINCTRL_STATE_DEFAULT);
+       if (IS_ERR(uap->pins_default))
+               dev_err(&dev->dev, "could not get default pinstate\n");
+
+       uap->pins_sleep = pinctrl_lookup_state(uap->pinctrl,
+                                              PINCTRL_STATE_SLEEP);
+       if (IS_ERR(uap->pins_sleep))
+               dev_dbg(&dev->dev, "could not get sleep pinstate\n");
 
        uap->clk = clk_get(&dev->dev, NULL);
        if (IS_ERR(uap->clk)) {