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SubjectRe: [PATCH 1/2] GPIO: Add driver for Zynq GPIO controller
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On 27 March 2014 16:25, Harini Katakam <harinik@xilinx.com> wrote:
> Add support for GPIO controller used by Xilinx Zynq
>
> Signed-off-by: Harini Katakam <harinik@xilinx.com>
> ---
> drivers/gpio/Kconfig | 7 +
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-zynq.c | 690 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 698 insertions(+)
> create mode 100644 drivers/gpio/gpio-zynq.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 903f24d..67a22a6 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -313,6 +313,13 @@ config GPIO_XTENSA
> Say yes here to support the Xtensa internal GPIO32 IMPWIRE (input)
> and EXPSTATE (output) ports
>
> +config GPIO_ZYNQ
> + bool "Xilinx ZYNQ GPIO support"
> + depends on ARCH_ZYNQ
> + select GENERIC_IRQ_CHIP
> + help
> + Say yes here to support Xilinx ZYNQ GPIO controller.
> +
> config GPIO_VR41XX
> tristate "NEC VR4100 series General-purpose I/O Uint support"
> depends on CPU_VR41XX
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 5d50179..439f23a 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -99,3 +99,4 @@ obj-$(CONFIG_GPIO_WM8350) += gpio-wm8350.o
> obj-$(CONFIG_GPIO_WM8994) += gpio-wm8994.o
> obj-$(CONFIG_GPIO_XILINX) += gpio-xilinx.o
> obj-$(CONFIG_GPIO_XTENSA) += gpio-xtensa.o
> +obj-$(CONFIG_GPIO_ZYNQ) += gpio-zynq.o
> diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c
> new file mode 100644
> index 0000000..1f5fdfc
> --- /dev/null
> +++ b/drivers/gpio/gpio-zynq.c
> @@ -0,0 +1,690 @@
> +/*
> + * Xilinx Zynq GPIO device driver
> + *
> + * Copyright (C) 2009 - 2014 Xilinx, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify it under
> + * the terms of the GNU General Public License as published by the Free Software
> + * Foundation; either version 2 of the License, or (at your option) any later
> + * version.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/gpio.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#define DRIVER_NAME "zynq-gpio"
> +#define ZYNQ_GPIO_NR_GPIOS 118
> +
> +static struct irq_domain *irq_domain;
> +
> +/* Register offsets for the GPIO device */
> +
> +/* LSW Mask & Data -WO */
> +#define ZYNQ_GPIO_DATA_LSW_OFFSET(BANK) (0x000 + (8 * BANK))
> +/* 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))
> +/* Direction mode reg-RW */
> +#define ZYNQ_GPIO_DIRM_OFFSET(BANK) (0x204 + (0x40 * BANK))
> +/* Output enable reg-RW */
> +#define ZYNQ_GPIO_OUTEN_OFFSET(BANK) (0x208 + (0x40 * BANK))
> +/* Interrupt mask reg-RO */
> +#define ZYNQ_GPIO_INTMASK_OFFSET(BANK) (0x20C + (0x40 * BANK))
> +/* Interrupt enable reg-WO */
> +#define ZYNQ_GPIO_INTEN_OFFSET(BANK) (0x210 + (0x40 * BANK))
> +/* Interrupt disable reg-WO */
> +#define ZYNQ_GPIO_INTDIS_OFFSET(BANK) (0x214 + (0x40 * BANK))
> +/* Interrupt status reg-RO */
> +#define ZYNQ_GPIO_INTSTS_OFFSET(BANK) (0x218 + (0x40 * BANK))
> +/* Interrupt type reg-RW */
> +#define ZYNQ_GPIO_INTTYPE_OFFSET(BANK) (0x21C + (0x40 * BANK))
> +/* Interrupt polarity reg-RW */
> +#define ZYNQ_GPIO_INTPOL_OFFSET(BANK) (0x220 + (0x40 * BANK))
> +/* Interrupt on any, reg-RW */
> +#define ZYNQ_GPIO_INTANY_OFFSET(BANK) (0x224 + (0x40 * BANK))
> +
> +/* Read/Write access to the GPIO PS registers */
> +static inline u32 zynq_gpio_readreg(void __iomem *offset)
> +{
> + return readl_relaxed(offset);
> +}
> +
> +static inline void zynq_gpio_writereg(void __iomem *offset, u32 val)
> +{
> + writel_relaxed(val, offset);
> +}
> +
> +static unsigned int zynq_gpio_pin_table[] = {
> + 31, /* 0 - 31 */
> + 53, /* 32 - 53 */
> + 85, /* 54 - 85 */
> + 117 /* 86 - 117 */
> +};
> +
> +/* Maximum banks */
> +#define ZYNQ_GPIO_MAX_BANK 4
> +
> +/* Disable all interrupts mask */
> +#define ZYNQ_GPIO_IXR_DISABLE_ALL 0xFFFFFFFF
> +
> +/* GPIO pin high */
> +#define ZYNQ_GPIO_PIN_HIGH 1
> +
> +/* Mid pin number of a bank */
> +#define ZYNQ_GPIO_MID_PIN_NUM 16
> +
> +/* GPIO upper 16 bit mask */
> +#define ZYNQ_GPIO_UPPER_MASK 0xFFFF0000
> +
> +/**
> + * struct zynq_gpio - gpio device private data structure
> + * @chip: instance of the gpio_chip
> + * @base_addr: base address of the GPIO device
> + * @irq: irq associated with the controller
> + * @irq_base: base of IRQ number for interrupt
> + * @clk: clock resource for this controller
> + */
> +struct zynq_gpio {
> + struct gpio_chip chip;
> + void __iomem *base_addr;
> + unsigned int irq;
> + unsigned int irq_base;
> + struct clk *clk;
> +};
> +
> +/**
> + * 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
> + * @bank_num: an output parameter used to return the bank number of the gpio
> + * pin
> + * @bank_pin_num: an output parameter used to return pin number within a bank
> + * for the given gpio pin
> + *
> + * Returns the bank number.
> + */
> +static inline void zynq_gpio_get_bank_pin(unsigned int pin_num,
> + unsigned int *bank_num,
> + unsigned int *bank_pin_num)
> +{
> + for (*bank_num = 0; *bank_num < ZYNQ_GPIO_MAX_BANK; (*bank_num)++)
> + if (pin_num <= zynq_gpio_pin_table[*bank_num])
> + break;
> +
> + if (!(*bank_num))
> + *bank_pin_num = pin_num;
> + else
> + *bank_pin_num = pin_num %
> + (zynq_gpio_pin_table[*bank_num - 1] + 1);
> +}
> +
> +/**
> + * zynq_gpio_get_value - Get the state of the specified pin of GPIO device
> + * @chip: gpio_chip instance to be worked on
> + * @pin: gpio pin number within the device
> + *
> + * This function reads the state of the specified pin of the GPIO device.
> + *
> + * Return: 0 if the pin is low, 1 if pin is high.
> + */
> +static int zynq_gpio_get_value(struct gpio_chip *chip, unsigned int pin)
> +{
> + unsigned int bank_num, bank_pin_num, data;
> + struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip);
> +
> + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num);
> +
> + data = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_DATA_OFFSET(bank_num));
> + return (data >> bank_pin_num) & ZYNQ_GPIO_PIN_HIGH;
> +}
> +
> +/**
> + * zynq_gpio_set_value - Modify the state of the pin with specified value
> + * @chip: gpio_chip instance to be worked on
> + * @pin: gpio pin number within the device
> + * @state: value used to modify the state of the specified pin
> + *
> + * This function calculates the register offset (i.e to lower 16 bits or
> + * upper 16 bits) based on the given pin number and sets the state of a
> + * gpio pin to the specified value. The state is either 0 or non-zero.
> + */
> +static void zynq_gpio_set_value(struct gpio_chip *chip, unsigned int pin,
> + int state)
> +{
> + unsigned int reg_offset, bank_num, bank_pin_num;
> + struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip);
> +
> + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num);
> +
> + if (bank_pin_num >= ZYNQ_GPIO_MID_PIN_NUM) {
> + /* only 16 data bits in bit maskable reg */
> + bank_pin_num -= ZYNQ_GPIO_MID_PIN_NUM;
> + reg_offset = ZYNQ_GPIO_DATA_MSW_OFFSET(bank_num);
> + } else {
> + reg_offset = ZYNQ_GPIO_DATA_LSW_OFFSET(bank_num);
> + }
> +
> + /*
> + * get the 32 bit value to be written to the mask/data register where
> + * the upper 16 bits is the mask and lower 16 bits is the data
> + */
> + if (state)
> + state = 1;
> + state = ~(1 << (bank_pin_num + ZYNQ_GPIO_MID_PIN_NUM)) &
> + ((state << bank_pin_num) | ZYNQ_GPIO_UPPER_MASK);
> +
> + zynq_gpio_writereg(gpio->base_addr + reg_offset, state);
> +}
> +
> +/**
> + * zynq_gpio_dir_in - Set the direction of the specified GPIO pin as input
> + * @chip: gpio_chip instance to be worked on
> + * @pin: gpio pin number within the device
> + *
> + * This function uses the read-modify-write sequence to set the direction of
> + * the gpio pin as input.
> + *
> + * Return: 0 always
> + */
> +static int zynq_gpio_dir_in(struct gpio_chip *chip, unsigned int pin)
> +{
> + unsigned int reg, bank_num, bank_pin_num;
> + struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip);
> +
> + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num);
> + /* clear the bit in direction mode reg to set the pin as input */
> + reg = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
> + reg &= ~(1 << bank_pin_num);
> + zynq_gpio_writereg(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num),
> + reg);
> +
> + return 0;
> +}
> +
> +/**
> + * zynq_gpio_dir_out - Set the direction of the specified GPIO pin as output
> + * @chip: gpio_chip instance to be worked on
> + * @pin: gpio pin number within the device
> + * @state: value to be written to specified pin
> + *
> + * This function sets the direction of specified GPIO pin as output, configures
> + * the Output Enable register for the pin and uses zynq_gpio_set to set
> + * the state of the pin to the value specified.
> + *
> + * Return: 0 always
> + */
> +static int zynq_gpio_dir_out(struct gpio_chip *chip, unsigned int pin,
> + int state)
> +{
> + struct zynq_gpio *gpio = container_of(chip, struct zynq_gpio, chip);
> + unsigned int reg, bank_num, bank_pin_num;
> +
> + zynq_gpio_get_bank_pin(pin, &bank_num, &bank_pin_num);
> +
> + /* set the GPIO pin as output */
> + reg = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_DIRM_OFFSET(bank_num));
> + reg |= 1 << bank_pin_num;
> + zynq_gpio_writereg(gpio->base_addr + ZYNQ_GPIO_DIRM_OFFSET(bank_num),
> + reg);
> +
> + /* configure the output enable reg for the pin */
> + reg = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_OUTEN_OFFSET(bank_num));
> + reg |= 1 << bank_pin_num;
> + zynq_gpio_writereg(gpio->base_addr + ZYNQ_GPIO_OUTEN_OFFSET(bank_num),
> + reg);
> +
> + /* set the state of the pin */
> + zynq_gpio_set_value(chip, pin, state);
> + return 0;
> +}
> +
> +static int zynq_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
> +{
> + return irq_find_mapping(irq_domain, offset);
> +}
> +
> +/**
> + * zynq_gpio_irq_ack - Acknowledge the interrupt of a gpio pin
> + * @irq_data: irq data containing irq number of gpio pin for the interrupt
> + * to ack
> + *
> + * This function calculates gpio pin number from irq number and sets the bit
> + * in the Interrupt Status Register of the corresponding bank, to ACK the irq.
> + */
> +static void zynq_gpio_irq_ack(struct irq_data *irq_data)
> +{
> + struct zynq_gpio *gpio = (struct zynq_gpio *)
> + irq_data_get_irq_chip_data(irq_data);
> + unsigned int device_pin_num, bank_num, bank_pin_num;
> +
> + device_pin_num = irq_data->hwirq;
> + zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num);
> + zynq_gpio_writereg(gpio->base_addr + ZYNQ_GPIO_INTSTS_OFFSET(bank_num),
> + 1 << bank_pin_num);
> +}
> +
> +/**
> + * zynq_gpio_irq_mask - Disable the interrupts for a gpio pin
> + * @irq_data: per irq and chip data passed down to chip functions
> + *
> + * This function calculates gpio pin number from irq number and sets the
> + * bit in the Interrupt Disable register of the corresponding bank to disable
> + * interrupts for that pin.
> + */
> +static void zynq_gpio_irq_mask(struct irq_data *irq_data)
> +{
> + struct zynq_gpio *gpio = (struct zynq_gpio *)
> + irq_data_get_irq_chip_data(irq_data);
> + unsigned int device_pin_num, bank_num, bank_pin_num;
> +
> + device_pin_num = irq_data->hwirq;
> + zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num);
> + zynq_gpio_writereg(gpio->base_addr + ZYNQ_GPIO_INTDIS_OFFSET(bank_num),
> + 1 << bank_pin_num);
> +}
> +
> +/**
> + * zynq_gpio_irq_unmask - Enable the interrupts for a gpio pin
> + * @irq_data: irq data containing irq number of gpio pin for the interrupt
> + * to enable
> + *
> + * This function calculates the gpio pin number from irq number and sets the
> + * bit in the Interrupt Enable register of the corresponding bank to enable
> + * interrupts for that pin.
> + */
> +static void zynq_gpio_irq_unmask(struct irq_data *irq_data)
> +{
> + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data);
> + unsigned int device_pin_num, bank_num, bank_pin_num;
> +
> + device_pin_num = irq_data->hwirq;
> + zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num);
> + zynq_gpio_writereg(gpio->base_addr + ZYNQ_GPIO_INTEN_OFFSET(bank_num),
> + 1 << bank_pin_num);
> +}
> +
> +/**
> + * zynq_gpio_set_irq_type - Set the irq type for a gpio pin
> + * @irq_data: irq data containing irq number of gpio pin
> + * @type: interrupt type that is to be set for the gpio pin
> + *
> + * This function gets the gpio pin number and its bank from the gpio pin number
> + * and configures the INT_TYPE, INT_POLARITY and INT_ANY registers.
> + *
> + * Return: 0, negative error otherwise.
> + * TYPE-EDGE_RISING, INT_TYPE - 1, INT_POLARITY - 1, INT_ANY - 0;
> + * TYPE-EDGE_FALLING, INT_TYPE - 1, INT_POLARITY - 0, INT_ANY - 0;
> + * TYPE-EDGE_BOTH, INT_TYPE - 1, INT_POLARITY - NA, INT_ANY - 1;
> + * TYPE-LEVEL_HIGH, INT_TYPE - 0, INT_POLARITY - 1, INT_ANY - NA;
> + * TYPE-LEVEL_LOW, INT_TYPE - 0, INT_POLARITY - 0, INT_ANY - NA
> + */
> +static int zynq_gpio_set_irq_type(struct irq_data *irq_data, unsigned int type)
> +{
> + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(irq_data);
> + unsigned int device_pin_num, bank_num, bank_pin_num;
> + unsigned int int_type, int_pol, int_any;
> +
> + device_pin_num = irq_data->hwirq;
> + zynq_gpio_get_bank_pin(device_pin_num, &bank_num, &bank_pin_num);
> +
> + int_type = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_INTTYPE_OFFSET(bank_num));
> + int_pol = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_INTPOL_OFFSET(bank_num));
> + int_any = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_INTANY_OFFSET(bank_num));
> +
> + /*
> + * based on the type requested, configure the INT_TYPE, INT_POLARITY
> + * and INT_ANY registers
> + */
> + switch (type) {
> + case IRQ_TYPE_EDGE_RISING:
> + int_type |= (1 << bank_pin_num);
> + int_pol |= (1 << bank_pin_num);
> + int_any &= ~(1 << bank_pin_num);
> + break;
> + case IRQ_TYPE_EDGE_FALLING:
> + int_type |= (1 << bank_pin_num);
> + int_pol &= ~(1 << bank_pin_num);
> + int_any &= ~(1 << bank_pin_num);
> + break;
> + case IRQ_TYPE_EDGE_BOTH:
> + int_type |= (1 << bank_pin_num);
> + int_any |= (1 << bank_pin_num);
> + break;
> + case IRQ_TYPE_LEVEL_HIGH:
> + int_type &= ~(1 << bank_pin_num);
> + int_pol |= (1 << bank_pin_num);
> + break;
> + case IRQ_TYPE_LEVEL_LOW:
> + int_type &= ~(1 << bank_pin_num);
> + int_pol &= ~(1 << bank_pin_num);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + zynq_gpio_writereg(gpio->base_addr +
> + ZYNQ_GPIO_INTTYPE_OFFSET(bank_num), int_type);
> + zynq_gpio_writereg(gpio->base_addr + ZYNQ_GPIO_INTPOL_OFFSET(bank_num),
> + int_pol);
> + zynq_gpio_writereg(gpio->base_addr + ZYNQ_GPIO_INTANY_OFFSET(bank_num),
> + int_any);
> + return 0;
> +}
> +
> +static int zynq_gpio_set_wake(struct irq_data *data, unsigned int on)
> +{
> + if (on)
> + zynq_gpio_irq_unmask(data);
> + else
> + zynq_gpio_irq_mask(data);
> +
> + return 0;
> +}
> +
> +/* irq chip descriptor */
> +static struct irq_chip zynq_gpio_irqchip = {
> + .name = DRIVER_NAME,
> + .irq_ack = zynq_gpio_irq_ack,
> + .irq_mask = zynq_gpio_irq_mask,
> + .irq_unmask = zynq_gpio_irq_unmask,
> + .irq_set_type = zynq_gpio_set_irq_type,
> + .irq_set_wake = zynq_gpio_set_wake,
> +};
> +
> +/**
> + * zynq_gpio_irqhandler - IRQ handler for the gpio banks of a gpio device
> + * @irq: irq number of the gpio bank where interrupt has occurred
> + * @desc: irq descriptor instance of the 'irq'
> + *
> + * This function reads the Interrupt Status Register of each bank to get the
> + * gpio pin number which has triggered an interrupt. It then acks the triggered
> + * interrupt and calls the pin specific handler set by the higher layer
> + * application for that pin.
> + * Note: A bug is reported if no handler is set for the gpio pin.
> + */
> +static void zynq_gpio_irqhandler(unsigned int irq, struct irq_desc *desc)
> +{
> + struct zynq_gpio *gpio = (struct zynq_gpio *)irq_get_handler_data(irq);
> + int gpio_irq = gpio->irq_base;
> + unsigned int int_sts, int_enb, bank_num;
> + struct irq_desc *gpio_irq_desc;
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> +
> + chained_irq_enter(chip, desc);
> +
> + for (bank_num = 0; bank_num < ZYNQ_GPIO_MAX_BANK; bank_num++) {
> + int_sts = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_INTSTS_OFFSET(bank_num));
> + int_enb = zynq_gpio_readreg(gpio->base_addr +
> + ZYNQ_GPIO_INTMASK_OFFSET(bank_num));
> + int_sts &= ~int_enb;
> +
> + for (; int_sts != 0; int_sts >>= 1, gpio_irq++) {
> + if (!(int_sts & 1))
> + continue;
> + gpio_irq_desc = irq_to_desc(gpio_irq);
> + BUG_ON(!gpio_irq_desc);
> + chip = irq_desc_get_chip(gpio_irq_desc);
> + BUG_ON(!chip);
> + chip->irq_ack(&gpio_irq_desc->irq_data);
> +
> + /* call the pin specific handler */
> + generic_handle_irq(gpio_irq);
> + }
> + /* shift to first virtual irq of next bank */
> + gpio_irq = gpio->irq_base + zynq_gpio_pin_table[bank_num] + 1;
> + }
> +
> + chip = irq_desc_get_chip(desc);
> + chained_irq_exit(chip, desc);
> +}
> +
> +static int __maybe_unused zynq_gpio_suspend(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct zynq_gpio *gpio = platform_get_drvdata(pdev);
> +
> + if (!device_may_wakeup(dev)) {
> + if (!pm_runtime_suspended(dev))

Would it not be more convenient to use pm_runtime_force_suspend() here?

> + clk_disable(gpio->clk);
> + return 0;
> + }
> +
> + return 0;
> +}
> +
> +static int __maybe_unused zynq_gpio_resume(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct zynq_gpio *gpio = platform_get_drvdata(pdev);
> +
> + if (!device_may_wakeup(dev)) {
> + if (!pm_runtime_suspended(dev))

Would it not be more convenient to use pm_runtime_force_resume() here?

> + return clk_enable(gpio->clk);
> + }
> +
> + return 0;
> +}
> +
> +static int __maybe_unused zynq_gpio_runtime_suspend(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct zynq_gpio *gpio = platform_get_drvdata(pdev);
> +
> + clk_disable(gpio->clk);

You should be able can use clk_disable_unprepare() here.

> +
> + return 0;
> +}
> +
> +static int __maybe_unused zynq_gpio_runtime_resume(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct zynq_gpio *gpio = platform_get_drvdata(pdev);
> +
> + return clk_enable(gpio->clk);

You should be able can use clk_prepare_enable() here.

> +}
> +
> +static int __maybe_unused zynq_gpio_idle(struct device *dev)
> +{
> + return pm_schedule_suspend(dev, 1);
> +}

You don't need this runtime PM idle callback, just set it to NULL.

> +
> +static int zynq_gpio_request(struct gpio_chip *chip, unsigned offset)
> +{
> + int ret;
> +
> + ret = pm_runtime_get_sync(chip->dev);
> +
> + /*
> + * If the device is already active pm_runtime_get() will return 1 on
> + * success, but gpio_request still needs to return 0.
> + */
> + return ret < 0 ? ret : 0;
> +}
> +
> +static void zynq_gpio_free(struct gpio_chip *chip, unsigned offset)
> +{
> + pm_runtime_put_sync(chip->dev);

You don't need the "sync" version here, using pm_runtime_put() should be enough.

> +}
> +
> +static const struct dev_pm_ops zynq_gpio_dev_pm_ops = {
> + SET_SYSTEM_SLEEP_PM_OPS(zynq_gpio_suspend, zynq_gpio_resume)
> + SET_RUNTIME_PM_OPS(zynq_gpio_runtime_suspend, zynq_gpio_runtime_resume,
> + zynq_gpio_idle)

Converting to use pm_runtime_force_suspend|resume(), means you need
use the SET_PM_RUNTIME_PM_OPS macro.

> +};
> +
> +/**
> + * zynq_gpio_probe - Initialization method for a zynq_gpio device
> + * @pdev: platform device instance
> + *
> + * This function allocates memory resources for the gpio device and registers
> + * all the banks of the device. It will also set up interrupts for the gpio
> + * pins.
> + * Note: Interrupts are disabled for all the banks during initialization.
> + *
> + * Return: 0 on success, negative error otherwise.
> + */
> +static int zynq_gpio_probe(struct platform_device *pdev)
> +{
> + int ret, pin_num, bank_num, gpio_irq;
> + unsigned int irq_num;
> + struct zynq_gpio *gpio;
> + struct gpio_chip *chip;
> + struct resource *res;
> +
> + gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
> + if (!gpio)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, gpio);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + gpio->base_addr = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(gpio->base_addr))
> + return PTR_ERR(gpio->base_addr);
> +
> + irq_num = platform_get_irq(pdev, 0);
> + gpio->irq = irq_num;
> +
> + /* configure the gpio chip */
> + chip = &gpio->chip;
> + chip->label = "zynq_gpio";
> + chip->owner = THIS_MODULE;
> + chip->dev = &pdev->dev;
> + chip->get = zynq_gpio_get_value;
> + chip->set = zynq_gpio_set_value;
> + chip->request = zynq_gpio_request;
> + chip->free = zynq_gpio_free;
> + chip->direction_input = zynq_gpio_dir_in;
> + chip->direction_output = zynq_gpio_dir_out;
> + chip->to_irq = zynq_gpio_to_irq;
> + chip->dbg_show = NULL;
> + chip->base = 0; /* default pin base */
> + chip->ngpio = ZYNQ_GPIO_NR_GPIOS;
> + chip->can_sleep = 0;
> +
> + gpio->irq_base = irq_alloc_descs(-1, 0, chip->ngpio, 0);
> + if (gpio->irq_base < 0) {
> + dev_err(&pdev->dev, "Couldn't allocate IRQ numbers\n");
> + return -ENODEV;
> + }
> +
> + irq_domain = irq_domain_add_legacy(pdev->dev.of_node,
> + chip->ngpio, gpio->irq_base, 0,
> + &irq_domain_simple_ops, NULL);
> +
> + /* report a bug if gpio chip registration fails */
> + ret = gpiochip_add(chip);
> + if (ret < 0)
> + return ret;
> +
> + /* Enable GPIO clock */
> + gpio->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(gpio->clk)) {
> + dev_err(&pdev->dev, "input clock not found.\n");
> + if (gpiochip_remove(chip))
> + dev_err(&pdev->dev, "Failed to remove gpio chip\n");
> + return PTR_ERR(gpio->clk);
> + }
> + ret = clk_prepare_enable(gpio->clk);
> + if (ret) {
> + dev_err(&pdev->dev, "Unable to enable clock.\n");
> + if (gpiochip_remove(chip))
> + dev_err(&pdev->dev, "Failed to remove gpio chip\n");
> + return ret;
> + }
> +
> + /* disable interrupts for all banks */
> + for (bank_num = 0; bank_num < ZYNQ_GPIO_MAX_BANK; bank_num++) {
> + zynq_gpio_writereg(gpio->base_addr +
> + ZYNQ_GPIO_INTDIS_OFFSET(bank_num),
> + ZYNQ_GPIO_IXR_DISABLE_ALL);
> + }
> +
> + /*
> + * set the irq chip, handler and irq chip data for callbacks for
> + * each pin
> + */
> + for (pin_num = 0; pin_num < min_t(int, ZYNQ_GPIO_NR_GPIOS,
> + (int)chip->ngpio); pin_num++) {
> + gpio_irq = irq_find_mapping(irq_domain, pin_num);
> + irq_set_chip_and_handler(gpio_irq, &zynq_gpio_irqchip,
> + handle_simple_irq);
> + irq_set_chip_data(gpio_irq, (void *)gpio);
> + set_irq_flags(gpio_irq, IRQF_VALID);
> + }
> +
> + irq_set_handler_data(irq_num, (void *)gpio);
> + irq_set_chained_handler(irq_num, zynq_gpio_irqhandler);
> +

add pm_runtime_set_active() to reflect the current state of the device.

> + pm_runtime_enable(&pdev->dev);
> +
> + device_set_wakeup_capable(&pdev->dev, 1);
> +
> + return 0;
> +}
> +
> +/**
> + * zynq_gpio_remove - Driver removal function
> + * @pdev: platform device instance
> + *
> + * Return: 0 always
> + */
> +static int zynq_gpio_remove(struct platform_device *pdev)
> +{
> + struct zynq_gpio *gpio = platform_get_drvdata(pdev);
> +

Converting to use clk_prepare|unprepare from the runtime PM callbacks,
means you can simplify the code here by using
pm_runtime_force_suspend().

If you don't like that, at least you need a pm_runtime_get_sync().

Kind regards
Ulf Hansson


> + clk_disable_unprepare(gpio->clk);
> + device_set_wakeup_capable(&pdev->dev, 0);
> + return 0;
> +}
> +
> +static struct of_device_id zynq_gpio_of_match[] = {
> + { .compatible = "xlnx,zynq-gpio-1.0", },
> + { /* end of table */ }
> +};
> +MODULE_DEVICE_TABLE(of, zynq_gpio_of_match);
> +
> +static struct platform_driver zynq_gpio_driver = {
> + .driver = {
> + .name = DRIVER_NAME,
> + .owner = THIS_MODULE,
> + .pm = &zynq_gpio_dev_pm_ops,
> + .of_match_table = zynq_gpio_of_match,
> + },
> + .probe = zynq_gpio_probe,
> + .remove = zynq_gpio_remove,
> +};
> +
> +/**
> + * zynq_gpio_init - Initial driver registration call
> + *
> + * Return: value from platform_driver_register
> + */
> +static int __init zynq_gpio_init(void)
> +{
> + return platform_driver_register(&zynq_gpio_driver);
> +}
> +
> +postcore_initcall(zynq_gpio_init);
> +
> +MODULE_AUTHOR("Xilinx, Inc.");
> +MODULE_DESCRIPTION("Zynq GPIO driver");
> +MODULE_LICENSE("GPL");
> --
> 1.7.9.5
>
> --
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