Re: [PATCH v3] gpio: dwapb: Add support for next generation of X-Gene SoC

From: Andy Shevchenko
Date: Tue Feb 21 2017 - 14:40:28 EST

On Tue, Feb 21, 2017 at 9:32 PM, Hoan Tran <hotran@xxxxxxx> wrote:
> Next generation of X-Gene SoC's GPIO hardware register map is very
> similar to DW GPIO. It only differs by a few register addresses.
> This patch modifies DW GPIO driver to accommodate the difference
> in a few register addresses.
>
> Signed-off-by: Hoan Tran <hotran@xxxxxxx>

I did 3 rounds of review, and to move it further I agree with below
code, though in the future it might be better to have separate IO
accessors per version of hardware. I'm also not sure about (uintptr_t)
casting (it's not a pointer at the end) and this might be modified to
use a data structure instead of plain integer in the future.

Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

> ---
> v3:
> * Add gpio_reg_v2_convert() function
> * Revise the register version parsing based on Andy's comment
>
> v2:
> * Remove ifdef CONFIG_ACPI
> ---
> drivers/gpio/gpio-dwapb.c | 91 ++++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 74 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c
> index 6193f62..b80ccdb 100644
> --- a/drivers/gpio/gpio-dwapb.c
> +++ b/drivers/gpio/gpio-dwapb.c
> @@ -21,6 +21,7 @@
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> +#include <linux/of_device.h>
> #include <linux/of_irq.h>
> #include <linux/platform_device.h>
> #include <linux/property.h>
> @@ -55,6 +56,14 @@
> #define GPIO_SWPORT_DR_SIZE (GPIO_SWPORTB_DR - GPIO_SWPORTA_DR)
> #define GPIO_SWPORT_DDR_SIZE (GPIO_SWPORTB_DDR - GPIO_SWPORTA_DDR)
>
> +#define GPIO_REG_OFFSET_V2 1
> +
> +#define GPIO_INTMASK_V2 0x44
> +#define GPIO_INTTYPE_LEVEL_V2 0x34
> +#define GPIO_INT_POLARITY_V2 0x38
> +#define GPIO_INTSTATUS_V2 0x3c
> +#define GPIO_PORTA_EOI_V2 0x40
> +
> struct dwapb_gpio;
>
> #ifdef CONFIG_PM_SLEEP
> @@ -87,14 +96,41 @@ struct dwapb_gpio {
> struct dwapb_gpio_port *ports;
> unsigned int nr_ports;
> struct irq_domain *domain;
> + unsigned int flags;
> };
>
> +static inline u32 gpio_reg_v2_convert(unsigned int offset)
> +{
> + switch (offset) {
> + case GPIO_INTMASK:
> + return GPIO_INTMASK_V2;
> + case GPIO_INTTYPE_LEVEL:
> + return GPIO_INTTYPE_LEVEL_V2;
> + case GPIO_INT_POLARITY:
> + return GPIO_INT_POLARITY_V2;
> + case GPIO_INTSTATUS:
> + return GPIO_INTSTATUS_V2;
> + case GPIO_PORTA_EOI:
> + return GPIO_PORTA_EOI_V2;
> + }
> +
> + return offset;
> +}
> +
> +static inline u32 gpio_reg_convert(struct dwapb_gpio *gpio, unsigned int offset)
> +{
> + if (gpio->flags & GPIO_REG_OFFSET_V2)
> + return gpio_reg_v2_convert(offset);
> +
> + return offset;
> +}
> +
> static inline u32 dwapb_read(struct dwapb_gpio *gpio, unsigned int offset)
> {
> struct gpio_chip *gc = &gpio->ports[0].gc;
> void __iomem *reg_base = gpio->regs;
>
> - return gc->read_reg(reg_base + offset);
> + return gc->read_reg(reg_base + gpio_reg_convert(gpio, offset));
> }
>
> static inline void dwapb_write(struct dwapb_gpio *gpio, unsigned int offset,
> @@ -103,7 +139,7 @@ static inline void dwapb_write(struct dwapb_gpio *gpio, unsigned int offset,
> struct gpio_chip *gc = &gpio->ports[0].gc;
> void __iomem *reg_base = gpio->regs;
>
> - gc->write_reg(reg_base + offset, val);
> + gc->write_reg(reg_base + gpio_reg_convert(gpio, offset), val);
> }
>
> static int dwapb_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
> @@ -336,8 +372,8 @@ static void dwapb_configure_irqs(struct dwapb_gpio *gpio,
> ct->chip.irq_disable = dwapb_irq_disable;
> ct->chip.irq_request_resources = dwapb_irq_reqres;
> ct->chip.irq_release_resources = dwapb_irq_relres;
> - ct->regs.ack = GPIO_PORTA_EOI;
> - ct->regs.mask = GPIO_INTMASK;
> + ct->regs.ack = gpio_reg_convert(gpio, GPIO_PORTA_EOI);
> + ct->regs.mask = gpio_reg_convert(gpio, GPIO_INTMASK);
> ct->type = IRQ_TYPE_LEVEL_MASK;
> }
>
> @@ -520,6 +556,21 @@ static void dwapb_gpio_unregister(struct dwapb_gpio *gpio)
> return pdata;
> }
>
> +static const struct of_device_id dwapb_of_match[] = {
> + { .compatible = "snps,dw-apb-gpio", .data = (void *)0},
> + { .compatible = "apm,xgene-gpio-v2", .data = (void *)GPIO_REG_OFFSET_V2},
> + { /* Sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, dwapb_of_match);
> +
> +static const struct acpi_device_id dwapb_acpi_match[] = {
> + {"HISI0181", 0},
> + {"APMC0D07", 0},
> + {"APMC0D81", GPIO_REG_OFFSET_V2},
> + { }
> +};
> +MODULE_DEVICE_TABLE(acpi, dwapb_acpi_match);
> +
> static int dwapb_gpio_probe(struct platform_device *pdev)
> {
> unsigned int i;
> @@ -555,6 +606,25 @@ static int dwapb_gpio_probe(struct platform_device *pdev)
> if (IS_ERR(gpio->regs))
> return PTR_ERR(gpio->regs);
>
> + gpio->flags = 0;
> + if (dev->of_node) {
> + const struct of_device_id *of_devid;
> +
> + of_devid = of_match_device(dwapb_of_match, dev);
> + if (of_devid) {
> + if (of_devid->data)
> + gpio->flags = (uintptr_t)of_devid->data;
> + }
> + } else if (has_acpi_companion(dev)) {
> + const struct acpi_device_id *acpi_id;
> +
> + acpi_id = acpi_match_device(dwapb_acpi_match, dev);
> + if (acpi_id) {
> + if (acpi_id->driver_data)
> + gpio->flags = acpi_id->driver_data;
> + }
> + }
> +
> for (i = 0; i < gpio->nr_ports; i++) {
> err = dwapb_gpio_add_port(gpio, &pdata->properties[i], i);
> if (err)
> @@ -581,19 +651,6 @@ static int dwapb_gpio_remove(struct platform_device *pdev)
> return 0;
> }
>
> -static const struct of_device_id dwapb_of_match[] = {
> - { .compatible = "snps,dw-apb-gpio" },
> - { /* Sentinel */ }
> -};
> -MODULE_DEVICE_TABLE(of, dwapb_of_match);
> -
> -static const struct acpi_device_id dwapb_acpi_match[] = {
> - {"HISI0181", 0},
> - {"APMC0D07", 0},
> - { }
> -};
> -MODULE_DEVICE_TABLE(acpi, dwapb_acpi_match);
> -
> #ifdef CONFIG_PM_SLEEP
> static int dwapb_gpio_suspend(struct device *dev)
> {
> --
> 1.9.1
>



--
With Best Regards,
Andy Shevchenko