Message-ID: <a9d4117d-9bc6-9273-7b8b-5b153c7a4ceb@codeaurora.org>
Date:   Tue, 29 Aug 2017 09:03:02 +0800
From:   Fenglin Wu <fenglinw@...eaurora.org>
To:     Shawn Guo <shawnguo@...nel.org>
Cc:     linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        bjorn.andersson@...aro.org,
        Linus Walleij <linus.walleij@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        linux-gpio@...r.kernel.org, devicetree@...r.kernel.org,
        collinsd@...eaurora.org, aghayal@...eaurora.org,
        wruan@...eaurora.org, kgunda@...eaurora.org
Subject: Re: [PATCH V1] pinctrl: qcom: spmi-gpio: Add support for
 qcom,gpios-disallowed property

On 8/28/2017 10:54 PM, Shawn Guo wrote:
> On Wed, Jul 19, 2017 at 03:17:07PM +0800, fenglinw@...eaurora.org wrote:
>> From: Fenglin Wu <fenglinw@...eaurora.org>
>>
>> Add support for qcom,gpios-disallowed property which is used to exclude
>> PMIC GPIOs not owned by the APSS processor from the pinctrl device.
> 
> If I understand it correctly, whether PMIC GPIOs is owned by APSS or not
> can be configured by firmware.  If that's true, I do not think we should
> have this qcom,gpios-disallowed thing in device tree, which is supposed
> to describe hardware not something software configurable.
> 
> Shawn

Hi Shawn,

I agree the GPIO's ownership is configurable and it always configured at
the very beginning of the device boot up which is not visible by linux
kernel drivers/image. Normally, this configuration is fixed in one
platform and it's been protected and not allowed to be configured in
linux kernel driver. So from linux driver point of view, this is a
hardware configuration. I agree the coming patch "spmi: pmic-arb: Move
the ownership check to irq_chip callback" would fix the pinctrl-
spmi-gpio driver probe failure caused by the ownership mismatch, but
this is just hiding the mistake of the kernel configured the GPIOs which
not owned by APPS processor. And these GPIOs will be registered
successfully as pinctrl pins and any APPS processor consumer drivers
could use this pins. This is not correct even the select_state operation
for these pins would failed due to the mode protection in spmi write_cmd
calling. I am thinking that not allowing these pins to be register as
pinctrl pins should be more straightforward and easy understanding. So I
think this patch still have value even the probe failure has been fixed
by the coming spmi patch.


Fenglin

> 
>> Signed-off-by: Fenglin Wu <fenglinw@...eaurora.org>
>> ---
>>   .../devicetree/bindings/pinctrl/qcom,pmic-gpio.txt |  12 ++
>>   drivers/pinctrl/qcom/pinctrl-spmi-gpio.c           | 202 +++++++++++++++++----
>>   2 files changed, 176 insertions(+), 38 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.txt b/Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.txt
>> index 8d893a8..435efe8 100644
>> --- a/Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.txt
>> +++ b/Documentation/devicetree/bindings/pinctrl/qcom,pmic-gpio.txt
>> @@ -43,6 +43,17 @@ PMIC's from Qualcomm.
>>   		    the first cell will be used to define gpio number and the
>>   		    second denotes the flags for this gpio
>>   
>> +- qcom,gpios-disallowed:
>> +	Usage: optional
>> +	Value type: <prop-encoded-array>
>> +	Definition: Array of the GPIO hardware numbers corresponding to GPIOs
>> +		    which the APSS processor is not allowed to configure.
>> +		    The hardware numbers are indexed from 1.
>> +		    The interrupt resources for these GPIOs must not be defined
>> +		    in "interrupts" and "interrupt-names" properties.
>> +		    GPIOs defined in this array won't be registered as pins
>> +		    in the pinctrl device or gpios in the gpio chip.
>> +
>>   Please refer to ../gpio/gpio.txt and ../interrupt-controller/interrupts.txt for
>>   a general description of GPIO and interrupt bindings.
>>   
>> @@ -206,6 +217,7 @@ Example:
>>   
>>   		gpio-controller;
>>   		#gpio-cells = <2>;
>> +		qcom,gpios-disallowed = <1 20>;
>>   
>>   		pm8921_gpio_keys: gpio-keys {
>>   			volume-keys {
>> diff --git a/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c b/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
>> index 664b641..74821af 100644
>> --- a/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
>> +++ b/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c
>> @@ -96,6 +96,7 @@
>>    * struct pmic_gpio_pad - keep current GPIO settings
>>    * @base: Address base in SPMI device.
>>    * @irq: IRQ number which this GPIO generate.
>> + * @gpio_idx: The index in GPIO's hardware number space (1-based)
>>    * @is_enabled: Set to false when GPIO should be put in high Z state.
>>    * @out_value: Cached pin output value
>>    * @have_buffer: Set to true if GPIO output could be configured in push-pull,
>> @@ -112,6 +113,7 @@
>>   struct pmic_gpio_pad {
>>   	u16		base;
>>   	int		irq;
>> +	int		gpio_idx;
>>   	bool		is_enabled;
>>   	bool		out_value;
>>   	bool		have_buffer;
>> @@ -130,6 +132,7 @@ struct pmic_gpio_state {
>>   	struct regmap	*map;
>>   	struct pinctrl_dev *ctrl;
>>   	struct gpio_chip chip;
>> +	const char **gpio_groups;
>>   };
>>   
>>   static const struct pinconf_generic_params pmic_gpio_bindings[] = {
>> @@ -231,7 +234,9 @@ static int pmic_gpio_get_function_groups(struct pinctrl_dev *pctldev,
>>   					 const char *const **groups,
>>   					 unsigned *const num_qgroups)
>>   {
>> -	*groups = pmic_gpio_groups;
>> +	struct pmic_gpio_state *state = pinctrl_dev_get_drvdata(pctldev);
>> +
>> +	*groups = state->gpio_groups;
>>   	*num_qgroups = pctldev->desc->npins;
>>   	return 0;
>>   }
>> @@ -455,7 +460,7 @@ static void pmic_gpio_config_dbg_show(struct pinctrl_dev *pctldev,
>>   
>>   	pad = pctldev->desc->pins[pin].drv_data;
>>   
>> -	seq_printf(s, " gpio%-2d:", pin + PMIC_GPIO_PHYSICAL_OFFSET);
>> +	seq_printf(s, " gpio%-2d:", pad->gpio_idx);
>>   
>>   	val = pmic_gpio_read(state, pad, PMIC_GPIO_REG_EN_CTL);
>>   
>> @@ -546,13 +551,29 @@ static int pmic_gpio_of_xlate(struct gpio_chip *chip,
>>   			      const struct of_phandle_args *gpio_desc,
>>   			      u32 *flags)
>>   {
>> +	int i;
>> +	struct pmic_gpio_state *state = gpiochip_get_data(chip);
>> +	struct pinctrl_desc *desc = state->ctrl->desc;
>> +	struct pmic_gpio_pad *pad;
>> +
>>   	if (chip->of_gpio_n_cells < 2)
>>   		return -EINVAL;
>>   
>>   	if (flags)
>>   		*flags = gpio_desc->args[1];
>>   
>> -	return gpio_desc->args[0] - PMIC_GPIO_PHYSICAL_OFFSET;
>> +	for (i = 0; i < chip->ngpio; i++) {
>> +		pad = desc->pins[i].drv_data;
>> +		if (pad->gpio_idx == gpio_desc->args[0]) {
>> +			dev_dbg(state->dev, "gpio%-2d xlate to pin%-2d\n",
>> +						gpio_desc->args[0], i);
>> +			return i;
>> +		}
>> +	}
>> +
>> +	dev_err(state->dev, "Couldn't find pin for gpio %d\n",
>> +				gpio_desc->args[0]);
>> +	return -ENODEV;
>>   }
>>   
>>   static int pmic_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
>> @@ -688,43 +709,124 @@ static int pmic_gpio_probe(struct platform_device *pdev)
>>   	struct pinctrl_desc *pctrldesc;
>>   	struct pmic_gpio_pad *pad, *pads;
>>   	struct pmic_gpio_state *state;
>> -	int ret, npins, i;
>> -	u32 reg;
>> +	int ret, npins, ngpios, i, j, pin_idx;
>> +	int disallowed_count = 0;
>> +	u32 reg[2], start, size;
>> +	u32 *disallowed = NULL;
>>   
>> -	ret = of_property_read_u32(dev->of_node, "reg", &reg);
>> +	ret = of_property_read_u32_array(dev->of_node, "reg", reg, 2);
>>   	if (ret < 0) {
>> -		dev_err(dev, "missing base address");
>> +		dev_err(dev, "reg property reading failed\n");
>>   		return ret;
>>   	}
>> +	start = reg[0];
>> +	size = reg[1];
>> +
>> +	ngpios = size / PMIC_GPIO_ADDRESS_RANGE;
>> +	if (ngpios == 0) {
>> +		dev_err(dev, "no gpios assigned\n");
>> +		return -ENODEV;
>> +	}
>>   
>> -	npins = platform_irq_count(pdev);
>> -	if (!npins)
>> +	if (ngpios > ARRAY_SIZE(pmic_gpio_groups)) {
>> +		dev_err(dev, "reg property defines %d gpios, but only %d are allowed\n",
>> +				ngpios, (int)ARRAY_SIZE(pmic_gpio_groups));
>>   		return -EINVAL;
>> -	if (npins < 0)
>> -		return npins;
>> +	}
>> +
>> +	if (of_find_property(dev->of_node, "qcom,gpios-disallowed",
>> +					&disallowed_count)) {
>> +		disallowed_count /= sizeof(u32);
>> +		if (disallowed_count == 0) {
>> +			dev_err(dev, "No data in gpios-disallowed\n");
>> +			return -EINVAL;
>> +		}
>>   
>> -	BUG_ON(npins > ARRAY_SIZE(pmic_gpio_groups));
>> +		disallowed = kcalloc(disallowed_count, sizeof(u32), GFP_KERNEL);
>> +		if (disallowed == NULL)
>> +			return -ENOMEM;
>> +
>> +		ret = of_property_read_u32_array(dev->of_node,
>> +				"qcom,gpios-disallowed",
>> +				disallowed, disallowed_count);
>> +		if (ret < 0) {
>> +			dev_err(dev, "qcom,gpios-disallowed property reading failed, ret=%d\n",
>> +								ret);
>> +			goto err_free;
>> +		}
>> +
>> +		for (i = 0; i < disallowed_count; i++) {
>> +			if (disallowed[i] >= ngpios + PMIC_GPIO_PHYSICAL_OFFSET
>> +				|| disallowed[i] < PMIC_GPIO_PHYSICAL_OFFSET) {
>> +				dev_err(dev, "invalid gpio = %d specified in qcom,gpios-disallowed, supported values: %d to %d\n",
>> +					disallowed[i],
>> +					PMIC_GPIO_PHYSICAL_OFFSET,
>> +					ngpios - 1 + PMIC_GPIO_PHYSICAL_OFFSET);
>> +				ret = -EINVAL;
>> +				goto err_free;
>> +			}
>> +			for (j = 0; j < i; j++) {
>> +				if (disallowed[i] == disallowed[j]) {
>> +					dev_err(dev, "duplicate gpio = %d listed in qcom,gpios-disallowed\n",
>> +							disallowed[i]);
>> +					ret = -EINVAL;
>> +					goto err_free;
>> +				}
>> +			}
>> +			dev_dbg(dev, "gpio %d NOT supported\n", disallowed[i]);
>> +		}
>> +	} else {
>> +		disallowed_count = 0;
>> +	}
>> +
>> +	npins = ngpios - disallowed_count;
>> +	if (npins <= 0) {
>> +		dev_err(dev, "No pins assigned\n");
>> +		ret = -ENODEV;
>> +		goto err_free;
>> +	}
>> +	if (platform_irq_count(pdev) != npins) {
>> +		dev_err(dev, "%d IRQs defined but %d expected\n",
>> +				platform_irq_count(pdev), npins);
>> +		ret = -EINVAL;
>> +		goto err_free;
>> +	}
>>   
>>   	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
>> -	if (!state)
>> -		return -ENOMEM;
>> +	if (!state) {
>> +		ret = -ENOMEM;
>> +		goto err_free;
>> +	}
>>   
>>   	platform_set_drvdata(pdev, state);
>>   
>>   	state->dev = &pdev->dev;
>>   	state->map = dev_get_regmap(dev->parent, NULL);
>>   
>> +	state->gpio_groups = devm_kcalloc(dev, sizeof(*state->gpio_groups),
>> +						npins, GFP_KERNEL);
>> +	if (!state->gpio_groups) {
>> +		ret = -ENOMEM;
>> +		goto err_free;
>> +	}
>> +
>>   	pindesc = devm_kcalloc(dev, npins, sizeof(*pindesc), GFP_KERNEL);
>> -	if (!pindesc)
>> -		return -ENOMEM;
>> +	if (!pindesc) {
>> +		ret = -ENOMEM;
>> +		goto err_free;
>> +	}
>>   
>>   	pads = devm_kcalloc(dev, npins, sizeof(*pads), GFP_KERNEL);
>> -	if (!pads)
>> -		return -ENOMEM;
>> +	if (!pads) {
>> +		ret = -ENOMEM;
>> +		goto err_free;
>> +	}
>>   
>>   	pctrldesc = devm_kzalloc(dev, sizeof(*pctrldesc), GFP_KERNEL);
>> -	if (!pctrldesc)
>> -		return -ENOMEM;
>> +	if (!pctrldesc) {
>> +		ret = -ENOMEM;
>> +		goto err_free;
>> +	}
>>   
>>   	pctrldesc->pctlops = &pmic_gpio_pinctrl_ops;
>>   	pctrldesc->pmxops = &pmic_gpio_pinmux_ops;
>> @@ -738,22 +840,42 @@ static int pmic_gpio_probe(struct platform_device *pdev)
>>   #ifdef CONFIG_DEBUG_FS
>>   	pctrldesc->custom_conf_items = pmic_conf_items;
>>   #endif
>> +	for (pin_idx = 0, i = 0; i < ngpios; i++) {
>> +		for (j = 0; j < disallowed_count; j++) {
>> +			if (i + PMIC_GPIO_PHYSICAL_OFFSET == disallowed[j])
>> +				break;
>> +		}
>> +		if (j != disallowed_count)
>> +			continue;
>>   
>> -	for (i = 0; i < npins; i++, pindesc++) {
>> -		pad = &pads[i];
>> +		pad = &pads[pin_idx];
>>   		pindesc->drv_data = pad;
>> -		pindesc->number = i;
>> +		pindesc->number = pin_idx;
>>   		pindesc->name = pmic_gpio_groups[i];
>>   
>> -		pad->irq = platform_get_irq(pdev, i);
>> -		if (pad->irq < 0)
>> -			return pad->irq;
>> +		pad->gpio_idx = i + PMIC_GPIO_PHYSICAL_OFFSET;
>> +		pad->irq = platform_get_irq(pdev, pin_idx);
>> +		if (pad->irq < 0) {
>> +			dev_err(state->dev,
>> +				"failed to get irq for gpio %d (pin %d), ret=%d\n",
>> +					pad->gpio_idx, pin_idx, pad->irq);
>> +			ret = pad->irq;
>> +			goto err_free;
>> +		}
>> +		/* Every pin is a group */
>> +		state->gpio_groups[pin_idx] = pmic_gpio_groups[i];
>>   
>> -		pad->base = reg + i * PMIC_GPIO_ADDRESS_RANGE;
>> +		pad->base = start + i * PMIC_GPIO_ADDRESS_RANGE;
>>   
>>   		ret = pmic_gpio_populate(state, pad);
>> -		if (ret < 0)
>> -			return ret;
>> +		if (ret < 0) {
>> +			dev_err(state->dev,
>> +				"failed to populate gpio %d, ret=%d\n",
>> +							i, ret);
>> +			goto err_free;
>> +		}
>> +		pindesc++;
>> +		pin_idx++;
>>   	}
>>   
>>   	state->chip = pmic_gpio_gpio_template;
>> @@ -765,25 +887,29 @@ static int pmic_gpio_probe(struct platform_device *pdev)
>>   	state->chip.can_sleep = false;
>>   
>>   	state->ctrl = devm_pinctrl_register(dev, pctrldesc, state);
>> -	if (IS_ERR(state->ctrl))
>> -		return PTR_ERR(state->ctrl);
>> +	if (IS_ERR(state->ctrl)) {
>> +		ret = PTR_ERR(state->ctrl);
>> +		dev_err(state->dev, "failed to register pinctrl device, ret=%d\n",
>> +							ret);
>> +		goto err_free;
>> +	}
>>   
>>   	ret = gpiochip_add_data(&state->chip, state);
>>   	if (ret) {
>> -		dev_err(state->dev, "can't add gpio chip\n");
>> -		return ret;
>> +		dev_err(state->dev, "can't add gpio chip, ret=%d\n", ret);
>> +		goto err_free;
>>   	}
>>   
>>   	ret = gpiochip_add_pin_range(&state->chip, dev_name(dev), 0, 0, npins);
>>   	if (ret) {
>> -		dev_err(dev, "failed to add pin range\n");
>> -		goto err_range;
>> +		dev_err(dev, "failed to add pin range\n, ret=%d\n", ret);
>> +		gpiochip_remove(&state->chip);
>> +		goto err_free;
>>   	}
>>   
>> -	return 0;
>> +err_free:
>> +	kfree(disallowed);
>>   
>> -err_range:
>> -	gpiochip_remove(&state->chip);
>>   	return ret;
>>   }
>>   
>> -- 
>> Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>> a Linux Foundation Collaborative Project.
>>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

-- 
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project.

Powered by blists - more mailing lists