[PATCH] gpio: omap: Save and restore sysconfig

[Tony Lindgren]

As we are using cpu_pm to save and restore context, we must also save and
restore the timer sysconfig register TIOCP_CFG. This is needed because
we are not calling PM runtime functions at all with cpu_pm.

We need to save the sysconfig on idle as it's value can get reconfigured by
PM runtime and can be different from the init time value. Device specific
flags like "ti,no-idle-on-init" can affect the init value.

Fixes: b764a5863fd8 ("gpio: omap: Remove custom PM calls and use cpu_pm instead")
Cc: Aaro Koskinen <aaro.koskinen at iki.fi>
Cc: Adam Ford <aford173 at gmail.com>
Cc: Andreas Kemnade <andreas at kemnade.info>
Cc: Grygorii Strashko <grygorii.strashko at ti.com>
Cc: Peter Ujfalusi <peter.ujfalusi at gmail.com>
Signed-off-by: Tony Lindgren <tony at atomide.com>
---
 drivers/gpio/gpio-omap.c                | 9 +++++++++
 include/linux/platform_data/gpio-omap.h | 3 +++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -29,6 +29,7 @@
 #define OMAP4_GPIO_DEBOUNCINGTIME_MASK 0xFF
 
 struct gpio_regs {
+	u32 sysconfig;
 	u32 irqenable1;
 	u32 irqenable2;
 	u32 wake_en;
@@ -1069,6 +1070,7 @@ static void omap_gpio_init_context(struct gpio_bank *p)
 	const struct omap_gpio_reg_offs *regs = p->regs;
 	void __iomem *base = p->base;
 
+	p->context.sysconfig	= readl_relaxed(base + regs->sysconfig);
 	p->context.ctrl		= readl_relaxed(base + regs->ctrl);
 	p->context.oe		= readl_relaxed(base + regs->direction);
 	p->context.wake_en	= readl_relaxed(base + regs->wkup_en);
@@ -1088,6 +1090,7 @@ static void omap_gpio_restore_context(struct gpio_bank *bank)
 	const struct omap_gpio_reg_offs *regs = bank->regs;
 	void __iomem *base = bank->base;
 
+	writel_relaxed(bank->context.sysconfig, base + regs->sysconfig);
 	writel_relaxed(bank->context.wake_en, base + regs->wkup_en);
 	writel_relaxed(bank->context.ctrl, base + regs->ctrl);
 	writel_relaxed(bank->context.leveldetect0, base + regs->leveldetect0);
@@ -1115,6 +1118,10 @@ static void omap_gpio_idle(struct gpio_bank *bank, bool may_lose_context)
 
 	bank->saved_datain = readl_relaxed(base + bank->regs->datain);
 
+	/* Save syconfig, it's runtime value can be different from init value */
+	if (bank->loses_context)
+		bank->context.sysconfig = readl_relaxed(base + bank->regs->sysconfig);
+
 	if (!bank->enabled_non_wakeup_gpios)
 		goto update_gpio_context_count;
 
@@ -1279,6 +1286,7 @@ static int gpio_omap_cpu_notifier(struct notifier_block *nb,
 
 static const struct omap_gpio_reg_offs omap2_gpio_regs = {
 	.revision =		OMAP24XX_GPIO_REVISION,
+	.sysconfig =		OMAP24XX_GPIO_SYSCONFIG,
 	.direction =		OMAP24XX_GPIO_OE,
 	.datain =		OMAP24XX_GPIO_DATAIN,
 	.dataout =		OMAP24XX_GPIO_DATAOUT,
@@ -1302,6 +1310,7 @@ static const struct omap_gpio_reg_offs omap2_gpio_regs = {
 
 static const struct omap_gpio_reg_offs omap4_gpio_regs = {
 	.revision =		OMAP4_GPIO_REVISION,
+	.sysconfig =		OMAP4_GPIO_SYSCONFIG,
 	.direction =		OMAP4_GPIO_OE,
 	.datain =		OMAP4_GPIO_DATAIN,
 	.dataout =		OMAP4_GPIO_DATAOUT,
diff --git a/include/linux/platform_data/gpio-omap.h b/include/linux/platform_data/gpio-omap.h
--- a/include/linux/platform_data/gpio-omap.h
+++ b/include/linux/platform_data/gpio-omap.h
@@ -85,6 +85,7 @@
  * omap2+ specific GPIO registers
  */
 #define OMAP24XX_GPIO_REVISION		0x0000
+#define OMAP24XX_GPIO_SYSCONFIG		0x0010
 #define OMAP24XX_GPIO_IRQSTATUS1	0x0018
 #define OMAP24XX_GPIO_IRQSTATUS2	0x0028
 #define OMAP24XX_GPIO_IRQENABLE2	0x002c
@@ -108,6 +109,7 @@
 #define OMAP24XX_GPIO_SETDATAOUT	0x0094
 
 #define OMAP4_GPIO_REVISION		0x0000
+#define OMAP4_GPIO_SYSCONFIG		0x0010
 #define OMAP4_GPIO_EOI			0x0020
 #define OMAP4_GPIO_IRQSTATUSRAW0	0x0024
 #define OMAP4_GPIO_IRQSTATUSRAW1	0x0028
@@ -148,6 +150,7 @@
 #ifndef __ASSEMBLER__
 struct omap_gpio_reg_offs {
 	u16 revision;
+	u16 sysconfig;
 	u16 direction;
 	u16 datain;
 	u16 dataout;
-- 
2.31.1