Acquire the device-reset GPIO and toggle this to reset the UFS device during initialization and host reset.
Based on downstream support implemented by Subhash Jadavani <[email protected]>. Tested-by: John Stultz <[email protected]> Signed-off-by: Bjorn Andersson <[email protected]> --- Changes since v1: - Added gpio to DT binding document - Fixed spelling of UFS .../devicetree/bindings/ufs/ufshcd-pltfrm.txt | 2 + drivers/scsi/ufs/ufshcd.c | 44 +++++++++++++++++++ drivers/scsi/ufs/ufshcd.h | 4 ++ 3 files changed, 50 insertions(+) diff --git a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt index a74720486ee2..d562d8b4919c 100644 --- a/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt +++ b/Documentation/devicetree/bindings/ufs/ufshcd-pltfrm.txt @@ -54,6 +54,8 @@ Optional properties: PHY reset from the UFS controller. - resets : reset node register - reset-names : describe reset node register, the "rst" corresponds to reset the whole UFS IP. +- device-reset-gpios : A phandle and gpio specifier denoting the GPIO connected + to the RESET pin of the UFS memory device. Note: If above properties are not defined it can be assumed that the supply regulators or clocks are always on. diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index a208589426b1..eaa384d67684 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -42,6 +42,7 @@ #include <linux/nls.h> #include <linux/of.h> #include <linux/bitfield.h> +#include <linux/gpio/consumer.h> #include "ufshcd.h" #include "ufs_quirks.h" #include "unipro.h" @@ -6135,6 +6136,25 @@ static int ufshcd_abort(struct scsi_cmnd *cmd) return err; } +/** + * ufshcd_device_reset() - toggle the (optional) device reset line + * @hba: per-adapter instance + * + * Toggles the (optional) reset line to reset the attached device. + */ +static void ufshcd_device_reset(struct ufs_hba *hba) +{ + /* + * The UFS device shall detect reset pulses of 1us, sleep for 10us to + * be on the safe side. + */ + gpiod_set_value_cansleep(hba->device_reset, 1); + usleep_range(10, 15); + + gpiod_set_value_cansleep(hba->device_reset, 0); + usleep_range(10, 15); +} + /** * ufshcd_host_reset_and_restore - reset and restore host controller * @hba: per-adapter instance @@ -6190,6 +6210,9 @@ static int ufshcd_reset_and_restore(struct ufs_hba *hba) int retries = MAX_HOST_RESET_RETRIES; do { + /* Reset the attached device */ + ufshcd_device_reset(hba); + err = ufshcd_host_reset_and_restore(hba); } while (err && --retries); @@ -7386,6 +7409,18 @@ static void ufshcd_variant_hba_exit(struct ufs_hba *hba) ufshcd_vops_exit(hba); } +static int ufshcd_init_device_reset(struct ufs_hba *hba) +{ + hba->device_reset = devm_gpiod_get_optional(hba->dev, "device-reset", + GPIOD_OUT_HIGH); + if (IS_ERR(hba->device_reset)) { + dev_err(hba->dev, "failed to acquire reset gpio: %ld\n", + PTR_ERR(hba->device_reset)); + } + + return PTR_ERR_OR_ZERO(hba->device_reset); +} + static int ufshcd_hba_init(struct ufs_hba *hba) { int err; @@ -7425,9 +7460,15 @@ static int ufshcd_hba_init(struct ufs_hba *hba) if (err) goto out_disable_vreg; + err = ufshcd_init_device_reset(hba); + if (err) + goto out_disable_variant; + hba->is_powered = true; goto out; +out_disable_variant: + ufshcd_vops_setup_regulators(hba, false); out_disable_vreg: ufshcd_setup_vreg(hba, false); out_disable_clks: @@ -8321,6 +8362,9 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) goto exit_gating; } + /* Reset the attached device */ + ufshcd_device_reset(hba); + /* Host controller enable */ err = ufshcd_hba_enable(hba); if (err) { diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 994d73d03207..4443928ba7d2 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -72,6 +72,8 @@ #define UFSHCD "ufshcd" #define UFSHCD_DRIVER_VERSION "0.2" +struct gpio_desc; + struct ufs_hba; enum dev_cmd_type { @@ -706,6 +708,8 @@ struct ufs_hba { struct device bsg_dev; struct request_queue *bsg_queue; + + struct gpio_desc *device_reset; }; /* Returns true if clocks can be gated. Otherwise false */ -- 2.18.0
