From b8416b2fedbf1cfe1c3645c627b2341d253880bd Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Wed, 28 Aug 2019 12:17:55 -0700 Subject: 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 . Link: https://lore.kernel.org/r/20190828191756.24312-3-bjorn.andersson@linaro.org Signed-off-by: Bjorn Andersson Acked-by: Rob Herring Acked-by: Avri Altman Signed-off-by: Martin K. Petersen --- drivers/scsi/ufs/ufs-qcom.c | 36 ++++++++++++++++++++++++++++++++++++ drivers/scsi/ufs/ufs-qcom.h | 4 ++++ 2 files changed, 40 insertions(+) (limited to 'drivers/scsi/ufs') 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 #include #include +#include #include #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; @@ -1542,6 +1552,31 @@ static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba) usleep_range(1000, 1100); } +/** + * 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 * @@ -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 -- cgit v1.2.3