Subject: [RFC PATCH 2/3] pinctrl: at91: add support for generic pinconf

From: [email-masked] (boris brezillon)
Date: Mon, 26 Aug 2013 20:45:09 +0200

Hello Jean-Christophe,

Le 26/08/2013 19:53, Jean-Christophe PLAGNIOL-VILLARD a ?crit :
> On 23:37 Sat 24 Aug     , Boris BREZILLON wrote:
>> Add support for generic pin configuration to pinctrl-at91 driver.
>>
>> Signed-off-by: Boris BREZILLON <[email-masked]>
>> ---
>>   .../bindings/pinctrl/atmel,at91-pinctrl.txt        |   43 +++-
>>   drivers/pinctrl/Kconfig                            |    2 +-
>>   drivers/pinctrl/pinctrl-at91.c                     |  265 ++++++++++++++++++--
>>   3 files changed, 289 insertions(+), 21 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
>> index 7ccae49..7a7c0c4 100644
>> --- a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
>> +++ b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt
>> @@ -18,7 +18,9 @@ mode) this pin can work on and the 'config' configures various pad settings
>>   such as pull-up, multi drive, etc.
>>   
>>   Required properties for iomux controller:
>> -- compatible: "atmel,at91rm9200-pinctrl"
>> +- compatible: "atmel,at91rm9200-pinctrl" or "atmel,at91sam9x5-pinctrl".
>> +  Add "generic-pinconf" to the compatible string list to use the generic pin
>> +  configuration syntax.
>>   - atmel,mux-mask: array of mask (periph per bank) to describe if a pin can be
>>     configured in this periph mode. All the periph and bank need to be describe.
>>   
>> @@ -83,6 +85,11 @@ Required properties for pin configuration node:
>>     setting. The format is atmel,pins = <PIN_BANK PIN_BANK_NUM PERIPH CONFIG>.
>>     The PERIPH 0 means gpio, PERIPH 1 is periph A, PERIPH 2 is periph B...
>>     PIN_BANK 0 is pioA, PIN_BANK 1 is pioB...
>> +  Dependending on the presence of the "generic-pinconf" string in the
>> +  compatible property the 4th cell is:
>> +   * a phandle referencing a generic pin config node (refer to
>> +     pinctrl-bindings.txt)
>> +   * an integer defining the pin config (see the following description)
>>   
>>   Bits used for CONFIG:
>>   PULL_UP		(1 << 0): indicate this pin need a pull up.
>> @@ -132,6 +139,40 @@ pinctrl at fffff400 {
>>   	};
>>   };
>>   
>> +or
>> +
>> +pinctrl at fffff400 {
>> +	#address-cells = <1>;
>> +	#size-cells = <1>;
>> +	ranges;
>> +	compatible = "atmel,at91rm9200-pinctrl", "generic-pinconf", "simple-bus";
> nack your break the backword compatibility
>
> if we use a old kernel with this new dt nothing will work
> as the old kernel will never known the the "generic-pinconf" means anything

Your're right, I didn't think of this case (old kernel with new dt).

> if we want to use generic-pinconf support you *CAN NOT* use atmel,at91rm9200-pinctrl
> in the compatible

What about using "atmel,at91xx-pinconf" instead of 
"atmel,at91xx-pinctrl" to notify
the generic pinconf compatibility (as done by single pinctrl driver) ?

>> +	reg = <0xfffff400 0x600>;
>> +
>> +	atmel,mux-mask = <
>> +	      /*    A         B     */
>> +	       0xffffffff 0xffc00c3b  /* pioA */
>> +	       0xffffffff 0x7fff3ccf  /* pioB */
>> +	       0xffffffff 0x007fffff  /* pioC */
>> +	      >;
>> +
>> +	pcfg_none: pcfg_none {
>> +		bias-disable;
>> +	};
>> +
>> +	pcfg_pull_up: pcfg_pull_up {
>> +		bias-pullup;
>> +	};
>> +
>> +	/* shared pinctrl settings */
>> +	dbgu {
>> +		pinctrl_dbgu: dbgu-0 {
>> +			atmel,pins =
>> +				<1 14 0x1 &pcfg_none		/* PB14 periph A */
>> +				 1 15 0x1 &pcfg_pull_up>;	/* PB15 periph A with pullup */
>> +		};
>> +	};
>> +};
>> +
>>   dbgu: serial at fffff200 {
>>   	compatible = "atmel,at91sam9260-usart";
>>   	reg = <0xfffff200 0x200>;
>> diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
>> index bdb1a87..55a4f2c 100644
>> --- a/drivers/pinctrl/Kconfig
>> +++ b/drivers/pinctrl/Kconfig
>> @@ -54,7 +54,7 @@ config PINCTRL_AT91
>>   	depends on OF
>>   	depends on ARCH_AT91
>>   	select PINMUX
>> -	select PINCONF
>> +	select GENERIC_PINCONF
>>   	help
>>   	  Say Y here to enable the at91 pinctrl driver
>>   
>> diff --git a/drivers/pinctrl/pinctrl-at91.c b/drivers/pinctrl/pinctrl-at91.c
>> index 7cce066..1994dd2 100644
>> --- a/drivers/pinctrl/pinctrl-at91.c
>> +++ b/drivers/pinctrl/pinctrl-at91.c
>> @@ -23,6 +23,7 @@
>>   #include <linux/gpio.h>
>>   #include <linux/pinctrl/machine.h>
>>   #include <linux/pinctrl/pinconf.h>
>> +#include <linux/pinctrl/pinconf-generic.h>
>>   #include <linux/pinctrl/pinctrl.h>
>>   #include <linux/pinctrl/pinmux.h>
>>   /* Since we request GPIOs from ourself */
>> @@ -32,6 +33,7 @@
>>   #include <mach/at91_pio.h>
>>   
>>   #include "core.h"
>> +#include "pinconf.h"
>>   
>>   #define MAX_NB_GPIO_PER_BANK	32
>>   
>> @@ -85,6 +87,21 @@ enum at91_mux {
>>   	AT91_MUX_PERIPH_D = 4,
>>   };
>>   
>> +struct at91_generic_pinconf {
>> +	unsigned long	*configs;
>> +	unsigned int	nconfigs;
>> +};
>> +
>> +enum at91_pinconf_type {
>> +	AT91_PINCONF_NATIVE,
>> +	AT91_PINCONF_GENERIC,
>> +};
>> +
>> +union at91_pinconf {
>> +	unsigned long			native;
>> +	struct at91_generic_pinconf	generic;
>> +};
>> +
>>   /**
>>    * struct at91_pmx_pin - describes an At91 pin mux
>>    * @bank: the bank of the pin
>> @@ -93,10 +110,11 @@ enum at91_mux {
>>    * @conf: the configuration of the pin: PULL_UP, MULTIDRIVE etc...
>>    */
>>   struct at91_pmx_pin {
>> -	uint32_t	bank;
>> -	uint32_t	pin;
>> -	enum at91_mux	mux;
>> -	unsigned long	conf;
>> +	uint32_t		bank;
>> +	uint32_t		pin;
>> +	enum at91_mux		mux;
>> +	enum at91_pinconf_type	conftype;
>> +	union at91_pinconf	conf;
>>   };
>>   
>>   /**
>> @@ -278,8 +296,16 @@ static int at91_dt_node_to_map(struct pinctrl_dev *pctldev,
>>   		new_map[i].type = PIN_MAP_TYPE_CONFIGS_PIN;
>>   		new_map[i].data.configs.group_or_pin =
>>   				pin_get_name(pctldev, grp->pins[i]);
>> -		new_map[i].data.configs.configs = &grp->pins_conf[i].conf;
>> -		new_map[i].data.configs.num_configs = 1;
>> +		if (!pctldev->desc->confops->is_generic) {
>> +			new_map[i].data.configs.configs =
>> +				&grp->pins_conf[i].conf.native;
>> +			new_map[i].data.configs.num_configs = 1;
>> +		} else {
>> +			new_map[i].data.configs.configs =
>> +				grp->pins_conf[i].conf.generic.configs;
>> +			new_map[i].data.configs.num_configs =
>> +				grp->pins_conf[i].conf.generic.nconfigs;
>> +		}
>>   	}
>>   
>>   	dev_dbg(pctldev->dev, "maps: function %s group %s num %d\n",
>> @@ -325,7 +351,7 @@ static void at91_mux_disable_interrupt(void __iomem *pio, unsigned mask)
>>   
>>   static unsigned at91_mux_get_pullup(void __iomem *pio, unsigned pin)
>>   {
>> -	return (readl_relaxed(pio + PIO_PUSR) >> pin) & 0x1;
>> +	return !((readl_relaxed(pio + PIO_PUSR) >> pin) & 0x1);
>>   }
>>   
>>   static void at91_mux_set_pullup(void __iomem *pio, unsigned mask, bool on)
>> @@ -407,6 +433,16 @@ static enum at91_mux at91_mux_get_periph(void __iomem *pio, unsigned mask)
>>   	return select + 1;
>>   }
>>   
>> +static bool at91_mux_get_output(void __iomem *pio, unsigned pin)
>> +{
>> +	return (readl_relaxed(pio + PIO_OSR) >> pin) & 0x1;
>> +}
>> +
>> +static void at91_mux_set_output(void __iomem *pio, unsigned mask, bool is_on)
>> +{
>> +	__raw_writel(mask, pio + (is_on ? PIO_OER : PIO_ODR));
>> +}
>> +
>>   static bool at91_mux_get_deglitch(void __iomem *pio, unsigned pin)
>>   {
>>   	return (__raw_readl(pio + PIO_IFSR) >> pin) & 0x1;
>> @@ -445,7 +481,7 @@ static void at91_mux_pio3_set_debounce(void __iomem *pio, unsigned mask,
>>   
>>   static bool at91_mux_pio3_get_pulldown(void __iomem *pio, unsigned pin)
>>   {
>> -	return (__raw_readl(pio + PIO_PPDSR) >> pin) & 0x1;
>> +	return !((__raw_readl(pio + PIO_PPDSR) >> pin) & 0x1);
>>   }
>>   
>>   static void at91_mux_pio3_set_pulldown(void __iomem *pio, unsigned mask, bool is_on)
>> @@ -492,12 +528,17 @@ static struct at91_pinctrl_mux_ops at91sam9x5_ops = {
>>   static void at91_pin_dbg(const struct device *dev, const struct at91_pmx_pin *pin)
>>   {
>>   	if (pin->mux) {
>> -		dev_dbg(dev, "pio%c%d configured as periph%c with conf = 0x%lu\n",
>> -			pin->bank + 'A', pin->pin, pin->mux - 1 + 'A', pin->conf);
>> +		dev_dbg(dev, "pio%c%d configured as periph%c",
>> +			pin->bank + 'A', pin->pin, pin->mux - 1 + 'A');
>>   	} else {
>> -		dev_dbg(dev, "pio%c%d configured as gpio with conf = 0x%lu\n",
>> -			pin->bank + 'A', pin->pin, pin->conf);
>> +		dev_dbg(dev, "pio%c%d configured as gpio",
>> +			pin->bank + 'A', pin->pin);
>>   	}
>> +
>> +	if (pin->conftype == AT91_PINCONF_NATIVE)
>> +		dev_dbg(dev, " with conf = 0x%lu\n", pin->conf.native);
>> +	else
>> +		dev_dbg(dev, "\n");
> do not change debug output

I do not change the debug output for the native pinconf binding, but I 
cannot print the config as
a single interger in hex format if the generic pinconf is used.
I must translate each config entry to a "property=value" string, or 
translate the generic config
array to a single native config integer.

Do you have something easier in mind ?

>>   }
>>   
>>   static int pin_check_config(struct at91_pinctrl *info, const char *name,
>> @@ -782,6 +823,157 @@ static const struct pinconf_ops at91_pinconf_ops = {
>>   	.pin_config_group_dbg_show	= at91_pinconf_group_dbg_show,
>>   };
>>   
>> +static int at91_generic_pinconf_get(struct pinctrl_dev *pctldev,
>> +				    unsigned pin_id, unsigned long *config)
>> +{
>> +	struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
>> +	enum pin_config_param param = pinconf_to_config_param(*config);
>> +	void __iomem *pio = pin_to_controller(info, pin_to_bank(pin_id));
>> +	unsigned pin = pin_id % MAX_NB_GPIO_PER_BANK;
>> +	int div;
>> +
>> +	switch (param) {
>> +	case PIN_CONFIG_BIAS_DISABLE:
>> +		if (at91_mux_get_pullup(pio, pin) &&
>> +		    (info->ops->get_pulldown ||
>> +		     !info->ops->get_pulldown(pio, pin)))
>> +			return -EINVAL;
>> +
>> +		*config = 0;
>> +		break;
>> +	case PIN_CONFIG_BIAS_PULL_UP:
>> +		if (!at91_mux_get_pullup(pio, pin))
>> +			return -EINVAL;
>> +
>> +		*config = 0;
>> +		break;
>> +	case PIN_CONFIG_BIAS_PULL_DOWN:
>> +		if (!info->ops->get_pulldown)
>> +			return -ENOTSUPP;
>> +		if (!info->ops->get_pulldown(pio, pin))
>> +			return -EINVAL;
>> +
>> +		*config = 0;
>> +		break;
>> +	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
>> +		if (!at91_mux_get_multidrive(pio, pin))
>> +			return -EINVAL;
>> +
>> +		*config = 0;
>> +		break;
>> +	case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
>> +		if (!info->ops->get_schmitt_trig)
>> +			return -ENOTSUPP;
>> +
>> +		if (!(info->ops->get_schmitt_trig(pio, pin)))
>> +			*config = 1;
>> +		else
>> +			*config = 0;
>> +		break;
>> +	case PIN_CONFIG_INPUT_DEBOUNCE:
>> +		if (!info->ops->get_debounce)
>> +			return -ENOTSUPP;
>> +
>> +		if (info->ops->get_debounce(pio, pin, &div)) {
>> +			/* TODO: replace 32768 with clk_get_rate(slck) return */
>> +			*config = ((div + 1) * 2) * 1000000 / 32768;
>> +			if (*config > 0xffff)
>> +				*config = 0xffff;
>> +		} else
>> +			*config = 0;
>> +		break;
>> +	case PIN_CONFIG_INPUT_DEGLITCH:
>> +		if (!info->ops->get_deglitch)
>> +			return -ENOTSUPP;
>> +
>> +		*config = info->ops->get_deglitch(pio, pin);
>> +		break;
>> +	case PIN_CONFIG_OUTPUT:
>> +		if (info->ops->get_periph(pio, pin) != AT91_MUX_GPIO)
>> +			return -EINVAL;
>> +
>> +		*config = at91_mux_get_output(pio, pin);
>> +		break;
>> +	default:
>> +		return -ENOTSUPP;
>> +		break;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int at91_generic_pinconf_set(struct pinctrl_dev *pctldev,
>> +				    unsigned pin_id, unsigned long config)
>> +{
>> +	struct at91_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
>> +	enum pin_config_param param = pinconf_to_config_param(config);
>> +	u16 arg = pinconf_to_config_argument(config);
>> +	u32 div = 0;
>> +	unsigned pin = pin_id % MAX_NB_GPIO_PER_BANK;
>> +	unsigned mask = pin_to_mask(pin);
>> +	void __iomem *pio = pin_to_controller(info, pin_to_bank(pin_id));
>> +
>> +	switch (param) {
>> +	case PIN_CONFIG_BIAS_DISABLE:
>> +		at91_mux_set_pullup(pio, mask, 0);
>> +		if (info->ops->set_pulldown)
>> +			info->ops->set_pulldown(pio, mask, 0);
>> +		break;
>> +	case PIN_CONFIG_BIAS_PULL_UP:
>> +		at91_mux_set_pullup(pio, mask, arg);
>> +		break;
>> +	case PIN_CONFIG_BIAS_PULL_DOWN:
>> +		if (!info->ops->set_pulldown)
>> +			return -ENOTSUPP;
>> +		info->ops->set_pulldown(pio, mask, arg);
>> +		break;
>> +	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
>> +		at91_mux_set_multidrive(pio, mask, 1);
>> +		break;
>> +	case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
>> +		if (!info->ops->disable_schmitt_trig)
>> +			return -ENOTSUPP;
>> +		if (arg)
>> +			mask = ~mask;
>> +		info->ops->disable_schmitt_trig(pio, mask);
>> +		break;
>> +	case PIN_CONFIG_INPUT_DEBOUNCE:
>> +		if (!info->ops->set_debounce)
>> +			return -ENOTSUPP;
>> +
>> +		/* TODO: replace 32768 with clk_get_rate(slck) return */
>> +		if (arg) {
>> +			div = (arg * 32768 / (2 * 1000000));
>> +			if (div)
>> +				div--;
>> +		}
>> +		info->ops->set_debounce(pio, mask, arg ? 1 : 0, div);
>> +		break;
>> +	case PIN_CONFIG_INPUT_DEGLITCH:
>> +		if (!info->ops->set_deglitch)
>> +			return -ENOTSUPP;
>> +
>> +		info->ops->set_deglitch(pio, mask, arg ? 1 : 0);
>> +		break;
>> +	case PIN_CONFIG_OUTPUT:
>> +		if (info->ops->get_periph(pio, pin) != AT91_MUX_GPIO)
>> +			return -EINVAL;
>> +		at91_mux_set_output(pio, mask, arg);
>> +		break;
>> +	default:
>> +		return -ENOTSUPP;
>> +		break;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct pinconf_ops at91_generic_pinconf_ops = {
>> +	.is_generic			= true,
>> +	.pin_config_get			= at91_generic_pinconf_get,
>> +	.pin_config_set			= at91_generic_pinconf_set,
>> +};
>> +
>>   static struct pinctrl_desc at91_pinctrl_desc = {
>>   	.pctlops	= &at91_pctrl_ops,
>>   	.pmxops		= &at91_pmx_ops,
>> @@ -847,6 +1039,7 @@ static int at91_pinctrl_parse_groups(struct device_node *np,
>>   	int size;
>>   	const __be32 *list;
>>   	int i, j;
>> +	int err;
>>   
>>   	dev_dbg(info->dev, "group(%d): %s\n", index, np->name);
>>   
>> @@ -870,21 +1063,48 @@ static int at91_pinctrl_parse_groups(struct device_node *np,
>>   				GFP_KERNEL);
>>   	grp->pins = devm_kzalloc(info->dev, grp->npins * sizeof(unsigned int),
>>   				GFP_KERNEL);
>> -	if (!grp->pins_conf || !grp->pins)
>> -		return -ENOMEM;
>> +	if (!grp->pins_conf || !grp->pins) {
>> +		err = -ENOMEM;
>> +		goto out_err;
>> +	}
> why ???

Right, I didn't notice the devm_kzalloc, I thought it was allocated 
using kzalloc.

>>   
>>   	for (i = 0, j = 0; i < size; i += 4, j++) {
>>   		pin->bank = be32_to_cpu(*list++);
>>   		pin->pin = be32_to_cpu(*list++);
>>   		grp->pins[j] = pin->bank * MAX_NB_GPIO_PER_BANK + pin->pin;
>>   		pin->mux = be32_to_cpu(*list++);
>> -		pin->conf = be32_to_cpu(*list++);
>> +		if (at91_pinctrl_desc.confops->is_generic) {
>> +			struct device_node *np_config;
>> +			const __be32 *phandle =	list++;
>> +
>> +			if (!phandle) {
>> +				err = -EINVAL;
>> +				goto out_err;
>> +			}
>> +			np_config =
>> +				of_find_node_by_phandle(be32_to_cpup(phandle));
>> +			pin->conftype = AT91_PINCONF_GENERIC;
>> +			err = pinconf_generic_parse_dt_config(np_config,
>> +						&pin->conf.generic.configs,
>> +						&pin->conf.generic.nconfigs);
>> +			if (err)
>> +				goto out_err;
>> +
>> +		} else {
>> +			pin->conftype = AT91_PINCONF_NATIVE;
>> +			pin->conf.native = be32_to_cpu(*list++);
>> +		}
>>   
>>   		at91_pin_dbg(info->dev, pin);
>>   		pin++;
>>   	}
>>   
>>   	return 0;
>> +
>> +out_err:
>> +	kfree(grp->pins_conf);
>> +	kfree(grp->pins);
> use devm and drop those kfree

Same mistake (devm_kzalloc is already used).
I'll drop this part for next version.

>> +	return err;
>>   }
>>   
>>   static int at91_pinctrl_parse_functions(struct device_node *np,
>> @@ -904,10 +1124,10 @@ static int at91_pinctrl_parse_functions(struct device_node *np,
>>   	/* Initialise function */
>>   	func->name = np->name;
>>   	func->ngroups = of_get_child_count(np);
>> -	if (func->ngroups <= 0) {
>> -		dev_err(info->dev, "no groups defined\n");
>> -		return -EINVAL;
>> -	}
>> +	/* This node might be a generic config definition: silently ignore it */
>> +	if (func->ngroups <= 0)
>> +		return 0;
>> +
>>   	func->groups = devm_kzalloc(info->dev,
>>   			func->ngroups * sizeof(char *), GFP_KERNEL);
>>   	if (!func->groups)
>> @@ -930,6 +1150,11 @@ static struct of_device_id at91_pinctrl_of_match[] = {
>>   	{ /* sentinel */ }
>>   };
>>   
>> +static struct of_device_id at91_pinconf_of_match[] = {
>> +	{ .compatible = "generic-pinconf" },
>> +	{ /* sentinel */ }
>> +};
>> +
>>   static int at91_pinctrl_probe_dt(struct platform_device *pdev,
>>   				 struct at91_pinctrl *info)
>>   {
>> @@ -945,6 +1170,8 @@ static int at91_pinctrl_probe_dt(struct platform_device *pdev,
>>   	info->dev = &pdev->dev;
>>   	info->ops = (struct at91_pinctrl_mux_ops *)
>>   		of_match_device(at91_pinctrl_of_match, &pdev->dev)->data;
>> +	if (of_match_device(at91_pinconf_of_match, &pdev->dev))
>> +		at91_pinctrl_desc.confops = &at91_generic_pinconf_ops;
>>   	at91_pinctrl_child_count(info, np);
>>   
>>   	if (info->nbanks < 1) {
>> -- 
>> 1.7.9.5
>>

Thanks for your review.

Best Regards,

Boris