[PATCH] serial/amba-pl011: move custom pin control to driver
Linus Walleij
linus.walleij at stericsson.com
Wed May 23 15:18:46 EDT 2012
From: Linus Walleij <linus.walleij at linaro.org>
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: linux-serial at vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Shawn Guo <shawn.guo at linaro.org>
Cc: Russell King <rmk+kernel at arm.linux.org.uk>
Reported-by: Lee Jones <lee.jones at linaro.org>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
arch/arm/mach-ux500/board-mop500.c | 54 +-----------------------------------
drivers/tty/serial/amba-pl011.c | 45 +++++++++++++++++++++++++++---
2 files changed, 42 insertions(+), 57 deletions(-)
diff --git a/arch/arm/mach-ux500/board-mop500.c b/arch/arm/mach-ux500/board-mop500.c
index 4bc0cbc..e7af625 100644
--- a/arch/arm/mach-ux500/board-mop500.c
+++ b/arch/arm/mach-ux500/board-mop500.c
@@ -540,43 +540,12 @@ 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,
};
@@ -598,28 +567,7 @@ 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
--- 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)) {
--
1.7.9.2
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