[U-Boot] [U-Boot, v2, 5/6] dm: sunxi: Modify the GPIO driver to support driver model

[Hans de Goede]

Hi,

On 10/23/2014 06:02 AM, Simon Glass wrote:
> This adds driver model support to the sunxi GPIO driver, using the device
> tree to trigger binding of the driver. The driver will still operate
> without driver model too.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> 
> Changes in v2:
> - Remove references to exynos and tegra
> - Use the word 'bank' instead of 'port'
> 
>  drivers/gpio/sunxi_gpio.c | 170 ++++++++++++++++++++++++++++++++++++++++++++++
>  include/configs/sun7i.h   |   1 +
>  2 files changed, 171 insertions(+)
> 
> diff --git a/drivers/gpio/sunxi_gpio.c b/drivers/gpio/sunxi_gpio.c
> index 0c50a8f..44135e5 100644
> --- a/drivers/gpio/sunxi_gpio.c
> +++ b/drivers/gpio/sunxi_gpio.c
> @@ -11,9 +11,25 @@
>   */
>  
>  #include <common.h>
> +#include <dm.h>
> +#include <errno.h>
> +#include <fdtdec.h>
> +#include <malloc.h>
>  #include <asm/io.h>
>  #include <asm/gpio.h>
> +#include <dm/device-internal.h>
>  
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +#define SUNXI_GPIOS_PER_BANK	SUNXI_GPIO_A_NR
> +
> +struct sunxi_gpio_platdata {
> +	struct sunxi_gpio *regs;
> +	const char *bank_name;	/* Name of bank, e.g. "B" */
> +	int gpio_count;
> +};
> +
> +#ifndef CONFIG_DM_GPIO
>  static int sunxi_gpio_output(u32 pin, u32 val)
>  {
>  	u32 dat;
> @@ -100,3 +116,157 @@ int sunxi_name_to_gpio(const char *name)
>  		return -1;
>  	return group * 32 + pin;
>  }
> +#endif
> +
> +#ifdef CONFIG_DM_GPIO
> +static int sunxi_gpio_direction_input(struct udevice *dev, unsigned offset)
> +{
> +	struct sunxi_gpio_platdata *plat = dev_get_platdata(dev);
> +
> +	sunxi_gpio_set_cfgbank(plat->regs, offset, SUNXI_GPIO_INPUT);
> +
> +	return 0;
> +}
> +
> +static int sunxi_gpio_direction_output(struct udevice *dev, unsigned offset,
> +				       int value)
> +{
> +	struct sunxi_gpio_platdata *plat = dev_get_platdata(dev);
> +	u32 num = GPIO_NUM(offset);
> +
> +	sunxi_gpio_set_cfgbank(plat->regs, offset, SUNXI_GPIO_OUTPUT);
> +	clrsetbits_le32(&plat->regs->dat, 1 << num, value ? (1 << num) : 0);
> +
> +	return 0;
> +}
> +
> +static int sunxi_gpio_get_value(struct udevice *dev, unsigned offset)
> +{
> +	struct sunxi_gpio_platdata *plat = dev_get_platdata(dev);
> +	u32 num = GPIO_NUM(offset);
> +	unsigned dat;
> +
> +	dat = readl(&plat->regs->dat);
> +	dat >>= num;
> +
> +	return dat & 0x1;
> +}
> +
> +static int sunxi_gpio_set_value(struct udevice *dev, unsigned offset,
> +				int value)
> +{
> +	struct sunxi_gpio_platdata *plat = dev_get_platdata(dev);
> +	u32 num = GPIO_NUM(offset);
> +
> +	clrsetbits_le32(&plat->regs->dat, 1 << num, value ? (1 << num) : 0);
> +	return 0;
> +}
> +
> +static int sunxi_gpio_get_function(struct udevice *dev, unsigned offset)
> +{
> +	struct sunxi_gpio_platdata *plat = dev_get_platdata(dev);
> +	int func;
> +
> +	func = sunxi_gpio_get_cfgbank(plat->regs, offset);
> +	if (func == SUNXI_GPIO_OUTPUT)
> +		return GPIOF_OUTPUT;
> +	else if (func == SUNXI_GPIO_INPUT)
> +		return GPIOF_INPUT;
> +	else
> +		return GPIOF_FUNC;
> +}
> +
> +static const struct dm_gpio_ops gpio_sunxi_ops = {
> +	.direction_input	= sunxi_gpio_direction_input,
> +	.direction_output	= sunxi_gpio_direction_output,
> +	.get_value		= sunxi_gpio_get_value,
> +	.set_value		= sunxi_gpio_set_value,
> +	.get_function		= sunxi_gpio_get_function,
> +};
> +
> +/**
> + * Returns the name of a GPIO bank
> + *
> + * GPIO banks are named A, B, C, ...
> + *
> + * @bank:	Bank number (0, 1..n-1)
> + * @return allocated string containing the name
> + */
> +static char *gpio_bank_name(int bank)
> +{
> +	char *name;
> +
> +	name = malloc(2);
> +	if (name) {
> +		name[0] = 'A' + bank;
> +		name[1] = '\0';
> +	}
> +
> +	return name;
> +}
> +
> +static int gpio_sunxi_probe(struct udevice *dev)
> +{
> +	struct sunxi_gpio_platdata *plat = dev_get_platdata(dev);
> +	struct gpio_dev_priv *uc_priv = dev->uclass_priv;
> +
> +	/* Tell the uclass how many GPIOs we have */
> +	if (plat) {
> +		uc_priv->gpio_count = plat->gpio_count;
> +		uc_priv->bank_name = plat->bank_name;
> +	}
> +
> +	return 0;
> +}
> +/**
> + * We have a top-level GPIO device with no actual GPIOs. It has a child
> + * device for each Sunxi bank.
> + */
> +static int gpio_sunxi_bind(struct udevice *parent)
> +{
> +	struct sunxi_gpio_platdata *plat = parent->platdata;
> +	struct sunxi_gpio_reg *ctlr;
> +	int bank;
> +	int ret;
> +
> +	/* If this is a child device, there is nothing to do here */
> +	if (plat)
> +		return 0;
> +
> +	ctlr = (struct sunxi_gpio_reg *)fdtdec_get_addr(gd->fdt_blob,
> +						   parent->of_offset, "reg");
> +	for (bank = 0; bank < SUNXI_GPIO_BANKS; bank++) {
> +		struct sunxi_gpio_platdata *plat;
> +		struct udevice *dev;
> +
> +		plat = calloc(1, sizeof(*plat));
> +		if (!plat)
> +			return -ENOMEM;
> +		plat->regs = &ctlr->gpio_bank[bank];
> +		plat->bank_name = gpio_bank_name(bank);
> +		plat->gpio_count = SUNXI_GPIOS_PER_BANK;

This is not correct, a bank have a maximum of 32 gpios but most
have less. I assume that this should be the number of actual pins in
the bank, correct ?

Our "gpio-pin-numbers" are based on a sparse numbering
scheme assuming 32 pins / bank, and there are assumptions this is
the case in various places, so we cannot fix this until we've
fully gone dm for all gpio usage. But here it would be nice
to have the actual numbers of pins.

Doing so requires at least one table with bank -> number of gpio-s
mapping. And I think it may also differ on SoC type in some cases
(I would need to take a look at the datasheets)

I suggest keeping this as is for now, and put fixing this with
a follow up patch on the todo list, and otherwise this looks good,
so this is:

Acked-by: Hans de Goede <hdegoede at redhat.com>



> +
> +		ret = device_bind(parent, parent->driver,
> +					plat->bank_name, plat, -1, &dev);
> +		if (ret)
> +			return ret;
> +		dev->of_offset = parent->of_offset;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct udevice_id sunxi_gpio_ids[] = {
> +	{ .compatible = "allwinner,sun7i-a20-pinctrl" },
> +	{ }
> +};
> +
> +U_BOOT_DRIVER(gpio_sunxi) = {
> +	.name	= "gpio_sunxi",
> +	.id	= UCLASS_GPIO,
> +	.ops	= &gpio_sunxi_ops,
> +	.of_match = sunxi_gpio_ids,
> +	.bind	= gpio_sunxi_bind,
> +	.probe	= gpio_sunxi_probe,
> +};
> +#endif
> diff --git a/include/configs/sun7i.h b/include/configs/sun7i.h
> index 500d0e3..2314e97 100644
> --- a/include/configs/sun7i.h
> +++ b/include/configs/sun7i.h
> @@ -38,6 +38,7 @@
>  
>  #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_DM)
>  # define CONFIG_CMD_DM
> +# define CONFIG_DM_GPIO
>  #endif
>  
>  /*
> 

Regards,

Hans