kernel/linux.git/drivers/mmc/core/regulator.c, branch linux-7.0.y

mmc: core: Add infrastructure for undervoltage handling

2025-08-22T10:08:07+00:00

Implement the core infrastructure to allow MMC bus types to handle REGULATOR_EVENT_UNDER_VOLTAGE events from power regulators. This is primarily aimed at allowing devices like eMMC to perform an emergency shutdown to prevent data corruption when a power failure is imminent. This patch introduces: - A new 'handle_undervoltage' function pointer to 'struct mmc_bus_ops'. Bus drivers (e.g., for eMMC) can implement this to define their emergency procedures. - A workqueue ('uv_work') in 'struct mmc_supply' to handle the event asynchronously in a high-priority context. - A new function 'mmc_handle_undervoltage()' which is called from the workqueue. It stops the host queue to prevent races with card removal, checks for the bus op, and invokes the handler. - Functions to register and unregister the regulator notifier, intended to be called by bus drivers like 'mmc_attach_mmc' when a compatible card is detected. The notifier is only registered for the main vmmc supply, as undervoltage handling for vqmmc or vqmmc2 is not required at this time. Signed-off-by: Oleksij Rempel Link: https://lore.kernel.org/r/20250821130751.2089587-2-o.rempel@pengutronix.de Signed-off-by: Ulf Hansson

mmc: core: Extend support for mmc regulators with a vqmmc2

2024-10-14T10:40:10+00:00

To allow an additional external regulator to be controlled by an mmc host driver, let's add support for a vqmmc2 regulator to the mmc core. For an SD UHS-II interface the vqmmc2 regulator may correspond to the so called vdd2 supply, as described by the SD spec. Initially, only 1.8V is needed, hence limit the new helper function, mmc_regulator_set_vqmmc2() to this too. Note that, to allow for flexibility mmc host drivers need to manage the enable/disable of the vqmmc2 regulator themselves, while the regulator is looked up through the common mmc_regulator_get_supply(). Signed-off-by: Ulf Hansson Link: https://lore.kernel.org/r/20240913102836.6144-5-victorshihgli@gmail.com

mmc: core: Use dev_err_probe for deferred regulators

2024-09-13T12:09:29+00:00

In case vmmc or vqmmc regulator is not available yet, use dev_err_probe in order to set a deferred probe reason. This is a helpful hint in /sys/kernel/debug/devices_deferred Signed-off-by: Alexander Stein Link: https://lore.kernel.org/r/20240911090910.3060749-1-alexander.stein@ew.tq-group.com Signed-off-by: Ulf Hansson

mmc: core: add helpers mmc_regulator_enable/disable_vqmmc

2023-03-23T10:38:34+00:00

There's a number of drivers (e.g. dw_mmc, meson-gx, mmci, sunxi) using the same mechanism and a private flag vqmmc_enabled to deal with enabling/disabling the vqmmc regulator. Move this to the core and create new helpers mmc_regulator_enable_vqmmc and mmc_regulator_disable_vqmmc. Signed-off-by: Heiner Kallweit Acked-by: Martin Blumenstingl Link: https://lore.kernel.org/r/71586432-360f-9b92-17f6-b05a8a971bc2@gmail.com Signed-off-by: Ulf Hansson

mmc: core: Allow invalid regulator in mmc_regulator_set_ocr()

2023-03-23T10:30:19+00:00

Basically all host drivers use code like this: if (!IS_ERR(mmc->supply.vmmc)) mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0) Move the IS_ERR() check to mmc_regulator_set_ocr() to simplify host driver code. Suggested-by: Ulf Hansson Signed-off-by: Heiner Kallweit Link: https://lore.kernel.org/r/0c1e7440-f4bc-b48a-137f-58b75ac98550@gmail.com Signed-off-by: Ulf Hansson

mmc: core: Add missing documetation for 'mmc' and 'ios'

2020-07-13T10:18:25+00:00

Remainder of the kerneldoc descriptions look present and correct. Fixes the following W=1 kernel build warnings: drivers/mmc/core/regulator.c:178: warning: Function parameter or member 'mmc' not described in 'mmc_regulator_set_vqmmc' drivers/mmc/core/regulator.c:178: warning: Function parameter or member 'ios' not described in 'mmc_regulator_set_vqmmc' Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20200701124702.908713-4-lee.jones@linaro.org Signed-off-by: Ulf Hansson

mmc: core: Return 1 from mmc_regulator_set_vqmmc() if switch skipped

2020-05-28T09:20:58+00:00

Adjust mmc_regulator_set_vqmmc() to return 1 if the voltage switch was skipped because the regulator voltage was already correct. This allows drivers to detect such condition and possibly skip various voltage switching extras. Signed-off-by: Marek Vasut Link: https://lore.kernel.org/r/20200416163649.336967-2-marex@denx.de Signed-off-by: Ulf Hansson

mmc: core: Convert mmc_regulator_get_ocrmask() to static

2019-02-25T14:20:58+00:00

The only left user of mmc_regulator_get_ocrmask() is the mmc core itself. Therefore, let's drop the export and turn it into static. Signed-off-by: Ulf Hansson

mmc: core: Move regulator helpers to separate file

2019-02-25T14:20:58+00:00

The mmc regulator helper functions, are placed in the extensive core.c file. In a step towards trying to create a better structure of files, avoiding too many lines of code per file, let's move these helpers to a new file, regulator.c. Moreover, this within this context it makes sense to also drop the export of mmc_vddrange_to_ocrmask(), but instead let's make it internal to the mmc core. Signed-off-by: Ulf Hansson