From 06aa09081d44c778309346ae8161841e0c104b7a Mon Sep 17 00:00:00 2001 From: Swapna Manupati Date: Mon, 7 Aug 2017 13:01:57 +0200 Subject: [PATCH] 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 Signed-off-by: Michal Simek Signed-off-by: Linus Walleij --- drivers/gpio/gpio-zynq.c | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-) 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 @@ static int zynq_gpio_is_zynq(struct zynq_gpio *gpio) } /** + * 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 @@ static int zynq_gpio_get_value(struct gpio_chip *chip, unsigned int pin) 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 dev_pm_ops zynq_gpio_dev_pm_ops = { 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 zynqmp_gpio_def = { 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(), -- 2.7.4