scsi: ufs: Remove pre-defined initial voltage values of device power
UFS specficication allows different VCC configurations for UFS devices, for example: (1). 2.70V - 3.60V (Activated by default in UFS core driver) (2). 1.70V - 1.95V (Activated if "vcc-supply-1p8" is declared in device tree) (3). 2.40V - 2.70V (Supported since UFS 3.x) With the introduction of UFS 3.x products, an issue is happening that UFS driver will use wrong "min_uV-max_uV" values to configure the voltage of VCC regulator on UFU 3.x products with the configuration (3) used. To solve this issue, we simply remove pre-defined initial VCC voltage values in UFS core driver with below reasons, 1. UFS specifications do not define how to detect the VCC configuration supported by attached device. 2. Device tree already supports standard regulator properties. Therefore VCC voltage shall be defined correctly in device tree, and shall not changed by UFS driver. What UFS driver needs to do is simply enable or disable the VCC regulator only. Similar change is applied to VCCQ and VCCQ2 as well. Note that we keep struct ufs_vreg unchanged. This allows vendors to configure proper min_uV and max_uV of any regulators to make regulator_set_voltage() works during regulator toggling flow in the future. Without specific vendor configurations, min_uV and max_uV will be NULL by default and UFS core driver will enable or disable the regulator only without adjusting its voltage. Link: https://lore.kernel.org/r/20201202091819.22363-1-stanley.chu@mediatek.com Reviewed-by:Asutosh Das <asutoshd@codeaurora.org> Reviewed-by:
Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by:
Can Guo <cang@codeaurora.org> Acked-by:
Avri Altman <avri.altman@wdc.com> Signed-off-by:
Stanley Chu <stanley.chu@mediatek.com> Signed-off-by:
Martin K. Petersen <martin.petersen@oracle.com>
parent
ab981054
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