[U-Boot] [PATCH 1/2] pinctrl: at91-pio4: add pinctrl driver

Andreas Bießmann andreas at biessmann.org
Tue May 3 12:47:55 CEST 2016


Dear Wenyou,

On 2016-04-07 04:15, Wenyou Yang wrote:
> AT91 PIO4 controller is a combined gpio-controller, pin-mux and
> pin-config module. The peripherals are assigned pins through per-pin
> based muxing logic. And the pin configuration are performed on
> specific registers which are shared along with the gpio controller.
> 
> Signed-off-by: Wenyou Yang <wenyou.yang at atmel.com>
> ---
> 
>  arch/arm/mach-at91/include/mach/atmel_pio4.h |  35 ++++++
>  drivers/pinctrl/Kconfig                      |   7 ++
>  drivers/pinctrl/Makefile                     |   1 +
>  drivers/pinctrl/pinctrl-at91-pio4.c          | 164 
> +++++++++++++++++++++++++++
>  4 files changed, 207 insertions(+)
>  create mode 100644 drivers/pinctrl/pinctrl-at91-pio4.c
> 
> diff --git a/arch/arm/mach-at91/include/mach/atmel_pio4.h
> b/arch/arm/mach-at91/include/mach/atmel_pio4.h
> index 8bb4b12..6760bec 100644
> --- a/arch/arm/mach-at91/include/mach/atmel_pio4.h
> +++ b/arch/arm/mach-at91/include/mach/atmel_pio4.h
> @@ -29,6 +29,41 @@ struct atmel_pio4_port {
> 
>  #endif
> 
> +/*
> + * PIO Configuration Register Fields
> + */
> +#define ATMEL_PIO_CFGR_FUNC_MASK	GENMASK(2, 0)
> +#define ATMEL_PIO_CFGR_FUNC_GPIO	(0x0 << 0)
> +#define ATMEL_PIO_CFGR_FUNC_PERIPH_A	(0x1 << 0)
> +#define ATMEL_PIO_CFGR_FUNC_PERIPH_B	(0x2 << 0)
> +#define ATMEL_PIO_CFGR_FUNC_PERIPH_C	(0x3 << 0)
> +#define ATMEL_PIO_CFGR_FUNC_PERIPH_D	(0x4 << 0)
> +#define ATMEL_PIO_CFGR_FUNC_PERIPH_E	(0x5 << 0)
> +#define ATMEL_PIO_CFGR_FUNC_PERIPH_F	(0x6 << 0)
> +#define ATMEL_PIO_CFGR_FUNC_PERIPH_G	(0x7 << 0)
> +#define ATMEL_PIO_DIR_MASK		BIT(8)
> +#define ATMEL_PIO_PUEN_MASK		BIT(9)
> +#define ATMEL_PIO_PDEN_MASK		BIT(10)
> +#define ATMEL_PIO_IFEN_MASK		BIT(12)
> +#define ATMEL_PIO_IFSCEN_MASK		BIT(13)
> +#define ATMEL_PIO_OPD_MASK		BIT(14)
> +#define ATMEL_PIO_SCHMITT_MASK		BIT(15)
> +#define ATMEL_PIO_CFGR_EVTSEL_MASK	GENMASK(26, 24)
> +#define ATMEL_PIO_CFGR_EVTSEL_FALLING	(0 << 24)
> +#define ATMEL_PIO_CFGR_EVTSEL_RISING	(1 << 24)
> +#define ATMEL_PIO_CFGR_EVTSEL_BOTH	(2 << 24)
> +#define ATMEL_PIO_CFGR_EVTSEL_LOW	(3 << 24)
> +#define ATMEL_PIO_CFGR_EVTSEL_HIGH	(4 << 24)
> +
> +#define ATMEL_PIO_NPINS_PER_BANK	32
> +#define ATMEL_PIO_BANK(pin_id)		(pin_id / ATMEL_PIO_NPINS_PER_BANK)
> +#define ATMEL_PIO_LINE(pin_id)		(pin_id % ATMEL_PIO_NPINS_PER_BANK)
> +#define ATMEL_PIO_BANK_OFFSET		0x40
> +
> +#define ATMEL_GET_PIN_NO(pinfunc)	((pinfunc) & 0xff)
> +#define ATMEL_GET_PIN_FUNC(pinfunc)	((pinfunc >> 16) & 0xf)
> +#define ATMEL_GET_PIN_IOSET(pinfunc)	((pinfunc >> 20) & 0xf)
> +
>  #define AT91_PIO_PORTA		0x0
>  #define AT91_PIO_PORTB		0x1
>  #define AT91_PIO_PORTC		0x2
> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
> index 2a69bab..e71f298 100644
> --- a/drivers/pinctrl/Kconfig
> +++ b/drivers/pinctrl/Kconfig
> @@ -105,6 +105,13 @@ config SPL_PINCONF
> 
>  if PINCTRL || SPL_PINCTRL
> 
> +config PINCTRL_AT91PIO4
> +	bool "AT91 PIO4 pinctrl driver"
> +	depends on DM
> +	help
> +	  This option is to enable the AT91 pinctrl driver for AT91 PIO4
> +	  controller which is available on SAMA5D2 SoC.
> +
>  config ROCKCHIP_PINCTRL
>  	bool "Rockchip pin control driver"
>  	depends on DM
> diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
> index 37dc904..bd0dea2 100644
> --- a/drivers/pinctrl/Makefile
> +++ b/drivers/pinctrl/Makefile
> @@ -5,6 +5,7 @@
>  obj-y					+= pinctrl-uclass.o
>  obj-$(CONFIG_$(SPL_)PINCTRL_GENERIC)	+= pinctrl-generic.o
> 
> +obj-$(CONFIG_PINCTRL_AT91PIO4)		+= pinctrl-at91-pio4.o
>  obj-y					+= nxp/
>  obj-$(CONFIG_ARCH_ROCKCHIP) += rockchip/
>  obj-$(CONFIG_PINCTRL_SANDBOX)	+= pinctrl-sandbox.o
> diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c
> b/drivers/pinctrl/pinctrl-at91-pio4.c
> new file mode 100644
> index 0000000..e4ca5dc
> --- /dev/null
> +++ b/drivers/pinctrl/pinctrl-at91-pio4.c
> @@ -0,0 +1,164 @@
> +/*
> + * Atmel PIO4 pinctrl driver
> + *
> + * Copyright (C) 2016 Atmel Corporation
> + *               Wenyou.Yang <wenyou.yang at atmel.com>
> + *
> + * SPDX-License-Identifier:	GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <dm/device.h>
> +#include <dm/pinctrl.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <mach/atmel_pio4.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +/*
> + * Warning:
> + * In order to not introduce confusion between Atmel PIO groups and 
> pinctrl
> + * framework groups, Atmel PIO groups will be called banks, line is 
> kept to
> + * designed the pin id into this bank.

full stop after 'will be called banks'. What does the rest of the 
sentence mean?

> + */
> +
> +struct atmel_pio4_platdata {
> +	struct atmel_pio4_port *reg_base;
> +};
> +
> +static const struct pinconf_param conf_params[] = {
> +	{ "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
> +	{ "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
> +	{ "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
> +	{ "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
> +	{ "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
> +	{ "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
> +	{ "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
> +};
> +
> +static u32 atmel_pinctrl_get_pinconf(const void *blob, int node)
> +{
> +	const struct pinconf_param *params;
> +	u32 param, arg, conf = 0;
> +	u32 i;
> +
> +	for (i = 0; i < ARRAY_SIZE(conf_params); i++) {
> +		params = &conf_params[i];
> +		if (!fdt_get_property(blob, node, params->property, NULL))
> +			continue;
> +
> +		param = params->param;
> +		arg = params->default_value;
> +
> +		switch (param) {
> +		case PIN_CONFIG_BIAS_DISABLE:
> +			conf &= (~ATMEL_PIO_PUEN_MASK);
> +			conf &= (~ATMEL_PIO_PDEN_MASK);
> +			break;
> +		case PIN_CONFIG_BIAS_PULL_UP:
> +			conf |= ATMEL_PIO_PUEN_MASK;
> +			break;
> +		case PIN_CONFIG_BIAS_PULL_DOWN:
> +			conf |= ATMEL_PIO_PDEN_MASK;
> +			break;
> +		case PIN_CONFIG_DRIVE_OPEN_DRAIN:
> +			conf |= ATMEL_PIO_OPD_MASK;
> +			break;
> +		case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
> +			if (arg == 0)
> +				conf |= ATMEL_PIO_SCHMITT_MASK;

I think we should also add the else path for arg != 0. You could argue 
that this is setup by conf = 0 above, but why should we disable the bias 
setup above then?

> +			break;
> +		case PIN_CONFIG_INPUT_DEBOUNCE:
> +			conf |= ATMEL_PIO_IFEN_MASK;
> +			conf |= ATMEL_PIO_IFSCEN_MASK;

For this case too, we should use the linux kernel way here too.

> +			break;

How about the output path for gpio?

> +		default:
> +			printf("%s: Unsupported configuration parameter: %u\n",
> +			       __func__, param);
> +			break;
> +		}
> +	}
> +
> +	return conf;
> +}
> +
> +static struct atmel_pio4_port *atmel_pio4_bank_base(struct udevice 
> *dev,
> +						    u32 bank)

I'd make this an inline function.

> +{
> +	struct atmel_pio4_platdata *platdata = dev_get_platdata(dev);
> +	struct atmel_pio4_port *bank_base =
> +			(struct atmel_pio4_port *)((u32)platdata->reg_base +
> +			ATMEL_PIO_BANK_OFFSET * bank);
> +
> +	return bank_base;
> +}
> +
> +static int atmel_pinctrl_set_state(struct udevice *dev, struct udevice 
> *config)
> +{
> +	struct atmel_pio4_port *bank_base;
> +	const void *blob = gd->fdt_blob;
> +	int node = config->of_offset;
> +	u32 offset, func, bank, line;
> +	u32 cells[40];
> +	u32 i, conf;
> +	int count;
> +
> +	conf = atmel_pinctrl_get_pinconf(blob, node);
> +
> +	count = fdtdec_get_int_array_count(blob, node, "pinmux",
> +					   cells, ARRAY_SIZE(cells));
> +	if (count < 0) {
> +		printf("%s: bad pinmux array %d\n", __func__, count);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0 ; i < count; i++) {

How about more than 40 entries? Could this be handled in any way?

> +		offset = ATMEL_GET_PIN_NO(cells[i]);
> +		func = ATMEL_GET_PIN_FUNC(cells[i]);
> +
> +		bank = ATMEL_PIO_BANK(offset);
> +		line = ATMEL_PIO_LINE(offset);
> +
> +		bank_base = atmel_pio4_bank_base(dev, bank);
> +
> +		writel(BIT(line), &bank_base->mskr);
> +		conf &= (~ATMEL_PIO_CFGR_FUNC_MASK);
> +		conf |= (func & ATMEL_PIO_CFGR_FUNC_MASK);
> +		writel(conf, &bank_base->cfgr);
> +	}
> +
> +	return 0;
> +}
> +
> +const struct pinctrl_ops atmel_pinctrl_ops  = {
> +	.set_state = atmel_pinctrl_set_state,
> +};
> +
> +static int atmel_pinctrl_probe(struct udevice *dev)
> +{
> +	struct atmel_pio4_platdata *platdata = dev_get_platdata(dev);
> +	fdt_addr_t addr_base;
> +
> +	addr_base = dev_get_addr(dev);
> +	if (addr_base == FDT_ADDR_T_NONE)
> +		return -ENODEV;
> +
> +	platdata->reg_base = (struct atmel_pio4_port *)addr_base;
> +
> +	return 0;
> +}
> +
> +static const struct udevice_id atmel_pinctrl_match[] = {
> +	{ .compatible = "atmel,sama5d2-pinctrl" },
> +	{}
> +};
> +
> +U_BOOT_DRIVER(atmel_pinctrl) = {
> +	.name = "pinctrl_atmel_pio4",
> +	.id = UCLASS_PINCTRL,
> +	.of_match = atmel_pinctrl_match,
> +	.probe = atmel_pinctrl_probe,
> +	.platdata_auto_alloc_size = sizeof(struct atmel_pio4_platdata),
> +	.ops = &atmel_pinctrl_ops,
> +};

Best regards

Andreas


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