Re: [PATCH v3 09/11] pinctrl: qcom-wcd934x: Add support to wcd934x pinctrl driver.

[Srinivas Kandagatla <srinivas.kandagatla@linaro.org>]

Thanks Stephen for reviewing this patch.

On 30/10/2019 14:50, Stephen Boyd wrote:
> Quoting Srinivas Kandagatla (2019-10-29 04:26:58)
>> From: Yeleswarapu Nagaradhesh <nagaradh@codeaurora.org>
>>
>> This patch adds support to wcd934x pinctrl block found in
>> WCD9340/WC9341 Audio codecs.
>>
>> [Srini: multiple cleanups to the code]
> 
> This goes after the author signoff and before yours. Can you add more
> details too?
I agree, will fix this in next spin.
> 
>> Signed-off-by: Yeleswarapu Nagaradhesh <nagaradh@codeaurora.org>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> ---
>>   drivers/pinctrl/qcom/Kconfig                |   7 +
>>   drivers/pinctrl/qcom/Makefile               |   1 +
>>   drivers/pinctrl/qcom/pinctrl-wcd934x-gpio.c | 365 ++++++++++++++++++++
>>   3 files changed, 373 insertions(+)
>>   create mode 100644 drivers/pinctrl/qcom/pinctrl-wcd934x-gpio.c
>>
>> diff --git a/drivers/pinctrl/qcom/pinctrl-wcd934x-gpio.c b/drivers/pinctrl/qcom/pinctrl-wcd934x-gpio.c
>> new file mode 100644
>> index 000000000000..1aff88d0bcb3
>> --- /dev/null
>> +++ b/drivers/pinctrl/qcom/pinctrl-wcd934x-gpio.c
>> @@ -0,0 +1,365 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Copyright (c) 2016-2017, The Linux Foundation. All rights reserved.
>> +// Copyright (c) 2019, Linaro Limited
>> +
>> +#include <linux/module.h>
>> +#include <linux/gpio.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_gpio.h>
>> +
>> +#include "../core.h"
>> +#include "../pinctrl-utils.h"
>> +
>> +#define WCD_REG_DIR_CTL_OFFSET 0x42
>> +#define WCD_REG_VAL_CTL_OFFSET 0x43
>> +#define WCD_GPIO_PULL_UP       1
>> +#define WCD_GPIO_PULL_DOWN     2
>> +#define WCD_GPIO_BIAS_DISABLE  3
>> +#define WCD_GPIO_STRING_LEN    20
>> +#define WCD934X_NPINS          5
>> +
>> +/**
>> + * struct wcd_gpio_pad - keep current GPIO settings
>> + * @offset: offset of gpio.
>> + * @is_valid: Set to false, when GPIO in high Z state.
>> + * @value: value of a pin
>> + * @output_enabled: Set to true if GPIO is output and false if it is input
>> + * @pullup: Constant current which flow through GPIO output buffer.
>> + * @strength: Drive strength of a pin
>> + */
>> +struct wcd_gpio_pad {
>> +       u16  offset;
>> +       bool is_valid;
>> +       bool value;
>> +       bool output_enabled;
>> +       unsigned int pullup;
>> +       unsigned int strength;
>> +};
>> +
>> +struct wcd_gpio_priv {
>> +       struct device *dev;
>> +       struct regmap *map;
>> +       struct pinctrl_dev *ctrl;
>> +       struct gpio_chip chip;
>> +};
>> +
>> +static int wcd_gpio_read(struct wcd_gpio_priv *priv_data,
>> +                        struct wcd_gpio_pad *pad, unsigned int addr)
>> +{
>> +       unsigned int val;
>> +       int ret;
>> +
>> +       ret = regmap_read(priv_data->map, addr, &val);
>> +       if (ret < 0)
>> +               dev_err(priv_data->dev, "%s: read 0x%x failed\n",
>> +                       __func__, addr);
>> +       else
>> +               ret = (val >> pad->offset);
>> +
>> +       return ret;
>> +}
>> +
>> +static int wcd_gpio_write(struct wcd_gpio_priv *priv_data,
>> +                         struct wcd_gpio_pad *pad, unsigned int addr,
>> +                         unsigned int val)
>> +{
>> +       int ret;
>> +
>> +       ret = regmap_update_bits(priv_data->map, addr, (1 << pad->offset),
>> +                                val << pad->offset);
>> +       if (ret < 0)
>> +               dev_err(priv_data->dev, "write 0x%x failed\n", addr);
> 
> Is there value in these error messages? Also, use %#x to get '0x'.

I can add ret in the err message.

I did not knew about "%#x".. nice, I will use this in future!
> 
>> +
>> +       return ret;
>> +}
> [...]
>> +
>> +static int wcd_pinctrl_probe(struct platform_device *pdev)
>> +{
>> +       struct device *dev = &pdev->dev;
>> +       struct pinctrl_pin_desc *pindesc;
>> +       struct pinctrl_desc *pctrldesc;
>> +       struct wcd_gpio_pad *pad, *pads;
>> +       struct wcd_gpio_priv *priv_data;
>> +       u32 npins = WCD934X_NPINS;
>> +       char **name;
>> +       int i;
>> +
>> +       priv_data = devm_kzalloc(dev, sizeof(*priv_data), GFP_KERNEL);
>> +       if (!priv_data)
>> +               return -ENOMEM;
>> +
>> +       priv_data->dev = dev;
>> +       priv_data->map = dev_get_regmap(dev->parent, NULL);
>> +       if (!priv_data->map) {
>> +               dev_err(dev, "%s: failed to get regmap\n", __func__);
>> +               return  -EINVAL;
>> +       }
>> +
>> +       pindesc = devm_kcalloc(dev, npins, sizeof(*pindesc), GFP_KERNEL);
>> +       if (!pindesc)
>> +               return -ENOMEM;
>> +
>> +       pads = devm_kcalloc(dev, npins, sizeof(*pads), GFP_KERNEL);
>> +       if (!pads)
>> +               return -ENOMEM;
> 
> Is it possible to put the pad struct around the pindesc struct? It's
> sort of sad that we have to allocate a chunk of memory twice for the
> pindesc and the pads when we could either use container_of() on the
> pindesc or just point the pindesc driver data member to the container
> structure for the qcom specific bits.
> 

I will give that a go in next version!

>> +
>> +       pctrldesc = devm_kzalloc(dev, sizeof(*pctrldesc), GFP_KERNEL);
>> +       if (!pctrldesc)
>> +               return -ENOMEM;
>> +
>> +       pctrldesc->pctlops = &wcd_pinctrl_ops;
>> +       pctrldesc->confops = &wcd_pinconf_ops;
>> +       pctrldesc->owner = THIS_MODULE;
>> +       pctrldesc->name = dev_name(dev);
>> +       pctrldesc->pins = pindesc;
>> +       pctrldesc->npins = npins;
>> +
>> +       name = devm_kcalloc(dev, npins, sizeof(char *), GFP_KERNEL);
>> +       if (!name)
>> +               return -ENOMEM;
>> +
>> +       for (i = 0; i < npins; i++, pindesc++) {
>> +               name[i] = devm_kzalloc(dev, sizeof(char) * WCD_GPIO_STRING_LEN,
>> +                                      GFP_KERNEL);
>> +               if (!name[i])
>> +                       return -ENOMEM;
>> +
>> +               pad = &pads[i];
>> +               pindesc->drv_data = pad;
>> +               pindesc->number = i;
>> +               snprintf(name[i], (WCD_GPIO_STRING_LEN - 1), "gpio%d", (i+1));
>> +               pindesc->name = name[i];
> 
> Why not use devm_kasprintf()? The 'name' array is also unnecessary?
Am not sure why its not used her, but I can do that change in next version.

> 
>> +               pad->offset = i;
>> +               pad->is_valid  = true;
>> +       }
>> +
>> +       priv_data->chip = wcd_gpio_chip;
>> +       priv_data->chip.parent = dev;
>> +       priv_data->chip.base = -1;
>> +       priv_data->chip.ngpio = npins;
>> +       priv_data->chip.label = dev_name(dev);
>> +       priv_data->chip.of_gpio_n_cells = 2;
>> +       priv_data->chip.can_sleep = false;
>> +       platform_set_drvdata(pdev, priv_data);
>> +
>> +       priv_data->ctrl = devm_pinctrl_register(dev, pctrldesc, priv_data);
>> +       if (IS_ERR(priv_data->ctrl)) {
>> +               dev_err(dev, "%s: failed to register to pinctrl\n", __func__);
>> +               return PTR_ERR(priv_data->ctrl);
>> +       }
>> +
>> +       return gpiochip_add_data(&priv_data->chip, priv_data);
> 
> WHy not use devm_gpiochip_add_data()?

Good idea, will do that in next spin.
> 
>> +}
>> +
>> +static int wcd_pinctrl_remove(struct platform_device *pdev)
>> +{
>> +       struct wcd_gpio_priv *priv_data = platform_get_drvdata(pdev);
>> +
>> +       gpiochip_remove(&priv_data->chip);
>> +
>> +       return 0;
> 
> And drop this function?
> 
>> +}
>> +
>> +static const struct of_device_id wcd_pinctrl_of_match[] = {
>> +       { .compatible = "qcom,wcd9340-pinctrl" },
>> +       { .compatible = "qcom,wcd9341-pinctrl" },
>> +       { },
> 
> Nitpick: Drop the comma on the sentinel.
> 
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, wcd_pinctrl_of_match);
> 
> Nitpick: Drop the newline between device table and match table.
>