commit 06aa09081d44c778309346ae8161841e0c104b7a
author Swapna Manupati <swapna.manupati@xilinx.com> Mon Aug 07 13:01:57 2017 +0200
committer Linus Walleij <linus.walleij@linaro.org> Mon Aug 14 15:57:06 2017 +0200
tree 3ead5cd274280b5be72facd25c1890ad24298eb4
parent e11de4de28c077d31235f5afcac91d4b4b0b7a6b

gpio: zynq: Provided workaround for GPIO

This patch provides workaround in the gpio driver
for Zynq and ZynqMP Platforms by reading pin value
of EMIO banks through DATA register as it was unable
to read the value of it from DATA_RO register.

Signed-off-by: Swapna Manupati <swapnam@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-zynq.c

diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c
index 0640338..a9ffe2d 100644
--- a/drivers/gpio/gpio-zynq.c
+++ b/drivers/gpio/gpio-zynq.c
@@ -67,6 +67,7 @@
 /* MSW Mask & Data -WO */
 #define ZYNQ_GPIO_DATA_MSW_OFFSET(BANK)	(0x004 + (8 * BANK))
 /* Data Register-RW */
+#define ZYNQ_GPIO_DATA_OFFSET(BANK)	(0x040 + (4 * BANK))
 #define ZYNQ_GPIO_DATA_RO_OFFSET(BANK)	(0x060 + (4 * BANK))
 /* Direction mode reg-RW */
 #define ZYNQ_GPIO_DIRM_OFFSET(BANK)	(0x204 + (0x40 * BANK))
@@ -98,6 +99,7 @@
 
 /* set to differentiate zynq from zynqmp, 0=zynqmp, 1=zynq */
 #define ZYNQ_GPIO_QUIRK_IS_ZYNQ	BIT(0)
+#define GPIO_QUIRK_DATA_RO_BUG	BIT(1)
 
 struct gpio_regs {
 	u32 datamsw[ZYNQMP_GPIO_MAX_BANK];
@@ -160,6 +162,17 @@
 }
 
 /**
+ * gpio_data_ro_bug - test if HW bug exists or not
+ * @gpio:       Pointer to driver data struct
+ *
+ * Return: 0 if bug doesnot exist, 1 if bug exists.
+ */
+static int gpio_data_ro_bug(struct zynq_gpio *gpio)
+{
+	return !!(gpio->p_data->quirks & GPIO_QUIRK_DATA_RO_BUG);
+}
+
+/**
  * zynq_gpio_get_bank_pin - Get the bank number and pin number within that bank
  * for a given pin in the GPIO device
  * @pin_num:	gpio pin number within the device
@@ -210,9 +223,28 @@
 
 	zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num, gpio);
 
-	data = readl_relaxed(gpio->base_addr +
-			     ZYNQ_GPIO_DATA_RO_OFFSET(bank_num));
-
+	if (gpio_data_ro_bug(gpio)) {
+		if (zynq_gpio_is_zynq(gpio)) {
+			if (bank_num <= 1) {
+				data = readl_relaxed(gpio->base_addr +
+					ZYNQ_GPIO_DATA_RO_OFFSET(bank_num));
+			} else {
+				data = readl_relaxed(gpio->base_addr +
+					ZYNQ_GPIO_DATA_OFFSET(bank_num));
+			}
+		} else {
+			if (bank_num <= 2) {
+				data = readl_relaxed(gpio->base_addr +
+					ZYNQ_GPIO_DATA_RO_OFFSET(bank_num));
+			} else {
+				data = readl_relaxed(gpio->base_addr +
+					ZYNQ_GPIO_DATA_OFFSET(bank_num));
+			}
+		}
+	} else {
+		data = readl_relaxed(gpio->base_addr +
+			ZYNQ_GPIO_DATA_RO_OFFSET(bank_num));
+	}
 	return (data >> bank_pin_num) & 1;
 }
 
@@ -704,6 +736,7 @@
 
 static const struct zynq_platform_data zynqmp_gpio_def = {
 	.label = "zynqmp_gpio",
+	.quirks = GPIO_QUIRK_DATA_RO_BUG,
 	.ngpio = ZYNQMP_GPIO_NR_GPIOS,
 	.max_bank = ZYNQMP_GPIO_MAX_BANK,
 	.bank_min[0] = ZYNQ_GPIO_BANK0_PIN_MIN(MP),
@@ -722,7 +755,7 @@
 
 static const struct zynq_platform_data zynq_gpio_def = {
 	.label = "zynq_gpio",
-	.quirks = ZYNQ_GPIO_QUIRK_IS_ZYNQ,
+	.quirks = ZYNQ_GPIO_QUIRK_IS_ZYNQ | GPIO_QUIRK_DATA_RO_BUG,
 	.ngpio = ZYNQ_GPIO_NR_GPIOS,
 	.max_bank = ZYNQ_GPIO_MAX_BANK,
 	.bank_min[0] = ZYNQ_GPIO_BANK0_PIN_MIN(),