[PATCH 1/8] gpio: zynq: Add support for suspend resume

From: Michal Simek
Date: Mon Aug 07 2017 - 07:03:57 EST


From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>

Add support for suspend resume. Now that we can lose context across
a suspend/ resume cycle. Add support for the context restore.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
---

drivers/gpio/gpio-zynq.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 79 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c
index df0851464006..064033803449 100644
--- a/drivers/gpio/gpio-zynq.c
+++ b/drivers/gpio/gpio-zynq.c
@@ -99,6 +99,17 @@
/* set to differentiate zynq from zynqmp, 0=zynqmp, 1=zynq */
#define ZYNQ_GPIO_QUIRK_IS_ZYNQ BIT(0)

+struct gpio_regs {
+ u32 datamsw[ZYNQMP_GPIO_MAX_BANK];
+ u32 datalsw[ZYNQMP_GPIO_MAX_BANK];
+ u32 dirm[ZYNQMP_GPIO_MAX_BANK];
+ u32 outen[ZYNQMP_GPIO_MAX_BANK];
+ u32 int_en[ZYNQMP_GPIO_MAX_BANK];
+ u32 int_dis[ZYNQMP_GPIO_MAX_BANK];
+ u32 int_type[ZYNQMP_GPIO_MAX_BANK];
+ u32 int_polarity[ZYNQMP_GPIO_MAX_BANK];
+ u32 int_any[ZYNQMP_GPIO_MAX_BANK];
+};
/**
* struct zynq_gpio - gpio device private data structure
* @chip: instance of the gpio_chip
@@ -106,6 +117,7 @@
* @clk: clock resource for this controller
* @irq: interrupt for the GPIO device
* @p_data: pointer to platform data
+ * @context: context registers
*/
struct zynq_gpio {
struct gpio_chip chip;
@@ -113,6 +125,7 @@ struct zynq_gpio {
struct clk *clk;
int irq;
const struct zynq_platform_data *p_data;
+ struct gpio_regs context;
};

/**
@@ -560,14 +573,72 @@ static void zynq_gpio_irqhandler(struct irq_desc *desc)
chained_irq_exit(irqchip, desc);
}

+static void zynq_gpio_save_context(struct zynq_gpio *gpio)
+{
+ unsigned int bank_num;
+
+ for (bank_num = 0; bank_num < gpio->p_data->max_bank; bank_num++) {
+ gpio->context.datalsw[bank_num] =
+ readl_relaxed(gpio->base_addr +
+ ZYNQ_GPIO_DATA_LSW_OFFSET(bank_num));
+ gpio->context.datamsw[bank_num] =
+ readl_relaxed(gpio->base_addr +
+ ZYNQ_GPIO_DATA_MSW_OFFSET(bank_num));
+ gpio->context.dirm[bank_num] = readl_relaxed(gpio->base_addr +
+ ZYNQ_GPIO_DIRM_OFFSET(bank_num));
+ gpio->context.int_en[bank_num] = readl_relaxed(gpio->base_addr +
+ ZYNQ_GPIO_INTMASK_OFFSET(bank_num));
+ gpio->context.int_type[bank_num] =
+ readl_relaxed(gpio->base_addr +
+ ZYNQ_GPIO_INTTYPE_OFFSET(bank_num));
+ gpio->context.int_polarity[bank_num] =
+ readl_relaxed(gpio->base_addr +
+ ZYNQ_GPIO_INTPOL_OFFSET(bank_num));
+ gpio->context.int_any[bank_num] =
+ readl_relaxed(gpio->base_addr +
+ ZYNQ_GPIO_INTANY_OFFSET(bank_num));
+ }
+}
+
+static void zynq_gpio_restore_context(struct zynq_gpio *gpio)
+{
+ unsigned int bank_num;
+
+ for (bank_num = 0; bank_num < gpio->p_data->max_bank; bank_num++) {
+ writel_relaxed(gpio->context.datalsw[bank_num],
+ gpio->base_addr +
+ ZYNQ_GPIO_DATA_LSW_OFFSET(bank_num));
+ writel_relaxed(gpio->context.datamsw[bank_num],
+ gpio->base_addr +
+ ZYNQ_GPIO_DATA_MSW_OFFSET(bank_num));
+ writel_relaxed(gpio->context.dirm[bank_num],
+ gpio->base_addr +
+ ZYNQ_GPIO_DIRM_OFFSET(bank_num));
+ writel_relaxed(gpio->context.int_en[bank_num],
+ gpio->base_addr +
+ ZYNQ_GPIO_INTEN_OFFSET(bank_num));
+ writel_relaxed(gpio->context.int_type[bank_num],
+ gpio->base_addr +
+ ZYNQ_GPIO_INTTYPE_OFFSET(bank_num));
+ writel_relaxed(gpio->context.int_polarity[bank_num],
+ gpio->base_addr +
+ ZYNQ_GPIO_INTPOL_OFFSET(bank_num));
+ writel_relaxed(gpio->context.int_any[bank_num],
+ gpio->base_addr +
+ ZYNQ_GPIO_INTANY_OFFSET(bank_num));
+ }
+}
static int __maybe_unused zynq_gpio_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
int irq = platform_get_irq(pdev, 0);
struct irq_data *data = irq_get_irq_data(irq);
+ struct zynq_gpio *gpio = platform_get_drvdata(pdev);

- if (!irqd_is_wakeup_set(data))
+ if (!irqd_is_wakeup_set(data)) {
+ zynq_gpio_save_context(gpio);
return pm_runtime_force_suspend(dev);
+ }

return 0;
}
@@ -577,9 +648,14 @@ static int __maybe_unused zynq_gpio_resume(struct device *dev)
struct platform_device *pdev = to_platform_device(dev);
int irq = platform_get_irq(pdev, 0);
struct irq_data *data = irq_get_irq_data(irq);
+ struct zynq_gpio *gpio = platform_get_drvdata(pdev);
+ int ret;

- if (!irqd_is_wakeup_set(data))
- return pm_runtime_force_resume(dev);
+ if (!irqd_is_wakeup_set(data)) {
+ ret = pm_runtime_force_resume(dev);
+ zynq_gpio_restore_context(gpio);
+ return ret;
+ }

return 0;
}
--
1.9.1