Re: [PATCH V2 2/3] scsi: ufs: Add regulator enable support

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On Tue, Aug 27, 2013 at 9:48 AM, Sujit Reddy Thumma
<sthumma@xxxxxxxxxxxxxx> wrote:
> UFS devices are powered by at most three external power supplies -
> - VCC - The flash memory core power supply, 2.7V to 3.6V or 1.70V to 1.95V
> - VCCQ - The controller and I/O power supply, 1.1V to 1.3V
> - VCCQ2 - Secondary controller and/or I/O power supply, 1.65V to 1.95V
>
> For some devices VCCQ or VCCQ2 are optional as they can be
> generated using internal LDO inside the UFS device.
>
> Add DT bindings for voltage regulators that can be controlled
> from host driver.
>
> Signed-off-by: Sujit Reddy Thumma <sthumma@xxxxxxxxxxxxxx>
> ---
>  .../devicetree/bindings/ufs/ufshcd-pltfrm.txt      |  24 +++
>  drivers/scsi/ufs/ufs.h                             |  25 +++
>  drivers/scsi/ufs/ufshcd-pltfrm.c                   | 100 +++++++++++
>  drivers/scsi/ufs/ufshcd.c                          | 193 ++++++++++++++++++++-
>  drivers/scsi/ufs/ufshcd.h                          |   3 +
>  5 files changed, 342 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> index 20468b2..65e3117 100644
> --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt
> @@ -8,9 +8,33 @@ Required properties:
>  - interrupts        : <interrupt mapping for UFS host controller IRQ>
>  - reg               : <registers mapping>
>
> +Optional properties:
> +- vcc-supply            : phandle to VCC supply regulator node
> +- vccq-supply           : phandle to VCCQ supply regulator node
> +- vccq2-supply          : phandle to VCCQ2 supply regulator node
> +- vcc-supply-1p8        : For embedded UFS devices, valid VCC range is 1.7-1.95V
> +                          or 2.7-3.6V. This boolean property when set, specifies
> +                         to use low voltage range of 1.7-1.95V. Note for external
> +                         UFS cards this property is invalid and valid VCC range is
> +                         always 2.7-3.6V.
> +- vcc-max-microamp      : specifies max. load that can be drawn from vcc supply
> +- vccq-max-microamp     : specifies max. load that can be drawn from vccq supply
> +- vccq2-max-microamp    : specifies max. load that can be drawn from vccq2 supply
> +
> +Note: If above properties are not defined it can be assumed that the supply
> +regulators are always on.
> +
>  Example:
>         ufshc@0xfc598000 {
>                 compatible = "jedec,ufs-1.1";
>                 reg = <0xfc598000 0x800>;
>                 interrupts = <0 28 0>;
> +
> +               vcc-supply = <&xxx_reg1>;
> +               vcc-supply-1p8;
> +               vccq-supply = <&xxx_reg2>;
> +               vccq2-supply = <&xxx_reg3>;
> +               vcc-max-microamp = 500000;
> +               vccq-max-microamp = 200000;
> +               vccq2-max-microamp = 200000;
>         };
> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
> index bce09a6..7db080e 100644
> --- a/drivers/scsi/ufs/ufs.h
> +++ b/drivers/scsi/ufs/ufs.h
> @@ -325,4 +325,29 @@ struct ufs_query_res {
>         struct utp_upiu_query upiu_res;
>  };
>
> +#define UFS_VREG_VCC_MIN_UV       2700000 /* uV */
> +#define UFS_VREG_VCC_MAX_UV       3600000 /* uV */
> +#define UFS_VREG_VCC_1P8_MIN_UV    1700000 /* uV */
> +#define UFS_VREG_VCC_1P8_MAX_UV    1950000 /* uV */
> +#define UFS_VREG_VCCQ_MIN_UV      1100000 /* uV */
> +#define UFS_VREG_VCCQ_MAX_UV      1300000 /* uV */
> +#define UFS_VREG_VCCQ2_MIN_UV     1650000 /* uV */
> +#define UFS_VREG_VCCQ2_MAX_UV     1950000 /* uV */
> +
> +struct ufs_vreg {
> +       struct regulator *reg;
> +       const char *name;
> +       bool enabled;
> +       int min_uV;
> +       int max_uV;
> +       int min_uA;
> +       int max_uA;
> +};
> +
> +struct ufs_vreg_info {
> +       struct ufs_vreg *vcc;
> +       struct ufs_vreg *vccq;
> +       struct ufs_vreg *vccq2;
> +};
> +
>  #endif /* End of Header */
> diff --git a/drivers/scsi/ufs/ufshcd-pltfrm.c b/drivers/scsi/ufs/ufshcd-pltfrm.c
> index 9c94052..cbdf5f3 100644
> --- a/drivers/scsi/ufs/ufshcd-pltfrm.c
> +++ b/drivers/scsi/ufs/ufshcd-pltfrm.c
> @@ -52,6 +52,99 @@ static struct ufs_hba_variant_ops *get_variant_ops(struct device *dev)
>         return NULL;
>  }
>
> +#define MAX_PROP_SIZE 32
> +static int ufshcd_populate_vreg(struct device *dev, const char *name,
> +               struct ufs_vreg **out_vreg)
> +{
> +       int ret = 0;
> +       char prop_name[MAX_PROP_SIZE];
> +       struct ufs_vreg *vreg = NULL;
> +       struct device_node *np = dev->of_node;
> +
> +       if (!np) {
> +               dev_err(dev, "%s: non DT initialization\n", __func__);
> +               goto out;
> +       }
> +
> +       snprintf(prop_name, MAX_PROP_SIZE, "%s-supply", name);
> +       if (!of_parse_phandle(np, prop_name, 0)) {
> +               dev_info(dev, "%s: Unable to find %s regulator, assuming enabled\n",
> +                               __func__, prop_name);
> +               goto out;
> +       }
> +
> +       vreg = devm_kzalloc(dev, sizeof(*vreg), GFP_KERNEL);
> +       if (!vreg) {
> +               dev_err(dev, "No memory for %s regulator\n", name);
> +               goto out;
> +       }
> +
> +       vreg->name = kstrdup(name, GFP_KERNEL);
> +
> +       snprintf(prop_name, MAX_PROP_SIZE, "%s-max-microamp", name);
> +       ret = of_property_read_u32(np, prop_name, &vreg->max_uA);
> +       if (ret) {
> +               dev_err(dev, "%s: unable to find %s err %d\n",
> +                               __func__, prop_name, ret);
> +               goto out_free;
> +       }
> +
> +       vreg->min_uA = 0;
> +       if (!strcmp(name, "vcc")) {
> +               if (of_property_read_bool(np, "vcc-supply-1p8")) {
> +                       vreg->min_uV = UFS_VREG_VCC_1P8_MIN_UV;
> +                       vreg->max_uV = UFS_VREG_VCC_1P8_MAX_UV;
> +               } else {
> +                       vreg->min_uV = UFS_VREG_VCC_MIN_UV;
> +                       vreg->max_uV = UFS_VREG_VCC_MAX_UV;
> +               }
> +       } else if (!strcmp(name, "vccq")) {
> +               vreg->min_uV = UFS_VREG_VCCQ_MIN_UV;
> +               vreg->max_uV = UFS_VREG_VCCQ_MAX_UV;
> +       } else if (!strcmp(name, "vccq2")) {
> +               vreg->min_uV = UFS_VREG_VCCQ2_MIN_UV;
> +               vreg->max_uV = UFS_VREG_VCCQ2_MAX_UV;
> +       }
> +
> +       goto out;
> +
> +out_free:
> +       devm_kfree(dev, vreg);
> +       vreg = NULL;
> +out:
> +       if (!ret)
> +               *out_vreg = vreg;
> +       return ret;
> +}
> +
> +/**
> + * ufshcd_parse_regulator_info - get regulator info from device tree
> + * @hba: per adapter instance
> + *
> + * Get regulator info from device tree for vcc, vccq, vccq2 power supplies.
> + * If any of the supplies are not defined it is assumed that they are always-on
> + * and hence return zero. If the property is defined but parsing is failed
> + * then return corresponding error.
> + */
> +static int ufshcd_parse_regulator_info(struct ufs_hba *hba)
> +{
> +       int err;
> +       struct device *dev = hba->dev;
> +       struct ufs_vreg_info *info = &hba->vreg_info;
> +
> +       err = ufshcd_populate_vreg(dev, "vcc", &info->vcc);
> +       if (err)
> +               goto out;
> +
> +       err = ufshcd_populate_vreg(dev, "vccq", &info->vccq);
> +       if (err)
> +               goto out;
> +
> +       err = ufshcd_populate_vreg(dev, "vccq2", &info->vccq2);
> +out:
> +       return err;
> +}
> +
>  #ifdef CONFIG_PM
>  /**
>   * ufshcd_pltfrm_suspend - suspend power management function
> @@ -172,6 +265,13 @@ static int ufshcd_pltfrm_probe(struct platform_device *pdev)
>
>         hba->vops = get_variant_ops(&pdev->dev);
>
> +       err = ufshcd_parse_regulator_info(hba);
> +       if (err) {
> +               dev_err(&pdev->dev, "%s: regulator init failed %d\n",
> +                               __func__, err);
> +               goto out;
> +       }
> +
>         pm_runtime_set_active(&pdev->dev);
>         pm_runtime_enable(&pdev->dev);
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 743696a..e520b15 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -59,6 +59,16 @@
>  /* Expose the flag value from utp_upiu_query.value */
>  #define MASK_QUERY_UPIU_FLAG_LOC 0xFF
>
> +#define ufshcd_toggle_vreg(_dev, _vreg, _on)                           \
> +       ({                                                              \
> +               int _ret;                                               \
> +               if (_on)                                                \
> +                       _ret = ufshcd_enable_vreg(_dev, _vreg);         \
> +               else                                                    \
> +                       _ret = ufshcd_disable_vreg(_dev, _vreg);        \
> +               _ret;                                                   \
> +       })
> +
>  enum {
>         UFSHCD_MAX_CHANNEL      = 0,
>         UFSHCD_MAX_ID           = 1,
> @@ -2826,6 +2836,153 @@ static struct scsi_host_template ufshcd_driver_template = {
>         .can_queue              = UFSHCD_CAN_QUEUE,
>  };
>
> +static int ufshcd_config_vreg(struct device *dev,
> +               struct ufs_vreg *vreg, bool on)
> +{
> +       int ret = 0;
> +       struct regulator *reg = vreg->reg;
> +       const char *name = vreg->name;
> +       int min_uV, uA_load;
> +
> +       BUG_ON(!vreg);
> +
> +       if (regulator_count_voltages(reg) > 0) {
> +               min_uV = on ? vreg->min_uV : 0;
> +               ret = regulator_set_voltage(reg, min_uV, vreg->max_uV);
> +               if (ret) {
> +                       dev_err(dev, "%s: %s set voltage failed, err=%d\n",
> +                                       __func__, name, ret);
> +                       goto out;
> +               }
> +
> +               uA_load = on ? vreg->max_uA : 0;
> +               ret = regulator_set_optimum_mode(reg, uA_load);
> +               if (ret >= 0) {
> +                       /*
> +                        * regulator_set_optimum_mode() returns new regulator
> +                        * mode upon success.
> +                        */
> +                       ret = 0;
> +               } else {
> +                       dev_err(dev, "%s: %s set optimum mode(uA_load=%d) failed, err=%d\n",
> +                                       __func__, name, uA_load, ret);
> +                       goto out;
> +               }
> +       }
> +out:
> +       return ret;
> +}
> +
> +static int ufshcd_enable_vreg(struct device *dev, struct ufs_vreg *vreg)
> +{
> +       int ret = 0;
> +
> +       if (!vreg || vreg->enabled)
> +               goto out;
> +
> +       ret = ufshcd_config_vreg(dev, vreg, true);
> +       if (!ret)
> +               ret = regulator_enable(vreg->reg);
> +
> +       if (!ret)
> +               vreg->enabled = true;

combine this 'if' also with the above 'if'.

> +       else
> +               dev_err(dev, "%s: %s enable failed, err=%d\n",
> +                               __func__, vreg->name, ret);
> +out:
> +       return ret;
> +}
> +
> +static int ufshcd_disable_vreg(struct device *dev, struct ufs_vreg *vreg)
> +{
> +       int ret = 0;
> +
> +       if (!vreg || !vreg->enabled)
> +               goto out;
> +
> +       ret = regulator_disable(vreg->reg);
> +
minor nitpick: remove the extra line.

> +       if (!ret) {
> +               /* ignore errors on applying disable config */
> +               ufshcd_config_vreg(dev, vreg, false);
> +               vreg->enabled = false;
> +       } else {
> +               dev_err(dev, "%s: %s disable failed, err=%d\n",
> +                               __func__, vreg->name, ret);
> +       }
> +out:
> +       return ret;
> +}
> +
> +static int ufshcd_setup_vreg(struct ufs_hba *hba, bool on)
> +{
> +       int ret = 0;
> +       struct device *dev = hba->dev;
> +       struct ufs_vreg_info *info = &hba->vreg_info;
> +
> +       if (!info)
> +               goto out;
> +
> +       ret = ufshcd_toggle_vreg(dev, info->vcc, on);
> +       if (ret)
> +               goto out;
> +
> +       ret = ufshcd_toggle_vreg(dev, info->vccq, on);
> +       if (ret)
> +               goto out;
> +
> +       ret = ufshcd_toggle_vreg(dev, info->vccq2, on);
> +       if (ret)
> +               goto out;

'if' is not needed

> +
> +out:
> +       if (ret) {
> +               ufshcd_toggle_vreg(dev, info->vccq2, false);
> +               ufshcd_toggle_vreg(dev, info->vccq, false);
> +               ufshcd_toggle_vreg(dev, info->vcc, false);
> +       }

Is this necessary even if 'vcc' toggle 'on' fails? Can it be done in
ufshcd_config_vreg() if regulator_set_optimum_mode() fails.

> +       return ret;
> +}
> +
> +static int ufshcd_get_vreg(struct device *dev, struct ufs_vreg *vreg)
> +{
> +       int ret = 0;
> +
> +       if (!vreg)
> +               goto out;
> +
> +       vreg->reg = devm_regulator_get(dev, vreg->name);
> +       if (IS_ERR(vreg->reg)) {
> +               ret = PTR_ERR(vreg->reg);
> +               dev_err(dev, "%s: %s get failed, err=%d\n",
> +                               __func__, vreg->name, ret);
> +       }
> +out:
> +       return ret;
> +}
> +
> +static int ufshcd_init_vreg(struct ufs_hba *hba)
> +{
> +       int ret = 0;
> +       struct device *dev = hba->dev;
> +       struct ufs_vreg_info *info = &hba->vreg_info;
> +
> +       if (!info)
> +               goto out;
> +
> +       ret = ufshcd_get_vreg(dev, info->vcc);
> +       if (ret)
> +               goto out;
> +
> +       ret = ufshcd_get_vreg(dev, info->vccq);
> +       if (ret)
> +               goto out;
> +
> +       ret = ufshcd_get_vreg(dev, info->vccq2);
> +out:
> +       return ret;
> +}
> +
>  static int ufshcd_variant_hba_init(struct ufs_hba *hba)
>  {
>         int err = 0;
> @@ -2881,6 +3038,36 @@ static void ufshcd_variant_hba_exit(struct ufs_hba *hba)
>                 hba->vops->exit(hba);
>  }
>
> +static int ufshcd_hba_init(struct ufs_hba *hba)
> +{
> +       int err;
> +
> +       err = ufshcd_init_vreg(hba);
> +       if (err)
> +               goto out;
> +
> +       err = ufshcd_setup_vreg(hba, true);
> +       if (err)
> +               goto out;
> +
> +       err = ufshcd_variant_hba_init(hba);
> +       if (err)
> +               goto out_disable_vreg;
> +
> +       goto out;
> +
> +out_disable_vreg:
> +       ufshcd_setup_vreg(hba, false);
> +out:
> +       return err;
> +}
> +
> +static void ufshcd_hba_exit(struct ufs_hba *hba)
> +{
> +       ufshcd_variant_hba_exit(hba);
> +       ufshcd_setup_vreg(hba, false);
> +}
> +
>  /**
>   * ufshcd_suspend - suspend power management function
>   * @hba: per adapter instance
> @@ -2966,7 +3153,7 @@ void ufshcd_remove(struct ufs_hba *hba)
>
>         scsi_host_put(hba->host);
>
> -       ufshcd_variant_hba_exit(hba);
> +       ufshcd_hba_exit(hba);
>  }
>  EXPORT_SYMBOL_GPL(ufshcd_remove);
>
> @@ -3029,7 +3216,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
>         hba->mmio_base = mmio_base;
>         hba->irq = irq;
>
> -       err = ufshcd_variant_hba_init(hba);
> +       err = ufshcd_hba_init(hba);
>         if (err)
>                 goto out_error;
>
> @@ -3115,7 +3302,7 @@ out_remove_scsi_host:
>         scsi_remove_host(hba->host);
>  out_disable:
>         scsi_host_put(host);
> -       ufshcd_variant_hba_exit(hba);
> +       ufshcd_hba_exit(hba);
>  out_error:
>         return err;
>  }
> diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
> index 72acbc7..f66e58c 100644
> --- a/drivers/scsi/ufs/ufshcd.h
> +++ b/drivers/scsi/ufs/ufshcd.h
> @@ -52,6 +52,7 @@
>  #include <linux/pm_runtime.h>
>  #include <linux/clk.h>
>  #include <linux/completion.h>
> +#include <linux/regulator/consumer.h>
>
>  #include <asm/irq.h>
>  #include <asm/byteorder.h>
> @@ -218,6 +219,7 @@ struct ufs_hba_variant_ops {
>   * @saved_uic_err: sticky UIC error mask
>   * @dev_cmd: ufs device management command information
>   * @auto_bkops_enabled: to track whether bkops is enabled in device
> + * @vreg_info: UFS device voltage regulator information
>   */
>  struct ufs_hba {
>         void __iomem *mmio_base;
> @@ -276,6 +278,7 @@ struct ufs_hba {
>         struct ufs_dev_cmd dev_cmd;
>
>         bool auto_bkops_enabled;
> +       struct ufs_vreg_info vreg_info;
>  };
>
>  #define ufshcd_writel(hba, val, reg)   \
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation.
>



-- 
~Santosh
--
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