diff options
| author | Bjorn Andersson <bjorn.andersson@linaro.org> | 2019-08-28 12:17:55 -0700 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2019-09-07 16:36:03 -0400 |
| commit | b8416b2fedbf1cfe1c3645c627b2341d253880bd (patch) | |
| tree | e2b085f6e9024efe16e13bee7bdd33018797a436 /drivers/scsi | |
| parent | d8d9f7931ac2698fc2b37d2db748c47122ee2a6f (diff) | |
| download | linux-b8416b2fedbf1cfe1c3645c627b2341d253880bd.tar.bz2 | |
scsi: ufs-qcom: Implement device_reset vops
The UFS_RESET pin on Qualcomm SoCs are controlled by TLMM and exposed
through the GPIO framework. Acquire the device-reset GPIO and use this to
implement the device_reset vops, to allow resetting the attached memory.
Based on downstream support implemented by Subhash Jadavani
<subhashj@codeaurora.org>.
Link: https://lore.kernel.org/r/20190828191756.24312-3-bjorn.andersson@linaro.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Avri Altman <Avri.Altman@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi')
| -rw-r--r-- | drivers/scsi/ufs/ufs-qcom.c | 36 | ||||
| -rw-r--r-- | drivers/scsi/ufs/ufs-qcom.h | 4 |
2 files changed, 40 insertions, 0 deletions
diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c index 02cdcefb81ac..a5b71487a206 100644 --- a/drivers/scsi/ufs/ufs-qcom.c +++ b/drivers/scsi/ufs/ufs-qcom.c @@ -8,6 +8,7 @@ #include <linux/of.h> #include <linux/platform_device.h> #include <linux/phy/phy.h> +#include <linux/gpio/consumer.h> #include <linux/reset-controller.h> #include "ufshcd.h" @@ -1137,6 +1138,15 @@ static int ufs_qcom_init(struct ufs_hba *hba) } } + host->device_reset = devm_gpiod_get_optional(dev, "reset", + GPIOD_OUT_HIGH); + if (IS_ERR(host->device_reset)) { + err = PTR_ERR(host->device_reset); + if (err != -EPROBE_DEFER) + dev_err(dev, "failed to acquire reset gpio: %d\n", err); + goto out_variant_clear; + } + err = ufs_qcom_bus_register(host); if (err) goto out_variant_clear; @@ -1543,6 +1553,31 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba) } /** + * ufs_qcom_device_reset() - toggle the (optional) device reset line + * @hba: per-adapter instance + * + * Toggles the (optional) reset line to reset the attached device. + */ +static void ufs_qcom_device_reset(struct ufs_hba *hba) +{ + struct ufs_qcom_host *host = ufshcd_get_variant(hba); + + /* reset gpio is optional */ + if (!host->device_reset) + return; + + /* + * The UFS device shall detect reset pulses of 1us, sleep for 10us to + * be on the safe side. + */ + gpiod_set_value_cansleep(host->device_reset, 1); + usleep_range(10, 15); + + gpiod_set_value_cansleep(host->device_reset, 0); + usleep_range(10, 15); +} + +/** * struct ufs_hba_qcom_vops - UFS QCOM specific variant operations * * The variant operations configure the necessary controller and PHY @@ -1562,6 +1597,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = { .suspend = ufs_qcom_suspend, .resume = ufs_qcom_resume, .dbg_register_dump = ufs_qcom_dump_dbg_regs, + .device_reset = ufs_qcom_device_reset, }; /** diff --git a/drivers/scsi/ufs/ufs-qcom.h b/drivers/scsi/ufs/ufs-qcom.h index 001915d1e0e4..d401f174bb70 100644 --- a/drivers/scsi/ufs/ufs-qcom.h +++ b/drivers/scsi/ufs/ufs-qcom.h @@ -195,6 +195,8 @@ struct ufs_qcom_testbus { u8 select_minor; }; +struct gpio_desc; + struct ufs_qcom_host { /* * Set this capability if host controller supports the QUniPro mode @@ -232,6 +234,8 @@ struct ufs_qcom_host { struct ufs_qcom_testbus testbus; struct reset_controller_dev rcdev; + + struct gpio_desc *device_reset; }; static inline u32 |