The patch regulator: core: Resolve coupled regulators has been applied to the regulator tree at https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >From d3d64537c33956c94cfa2376b87d8917868a0f5e Mon Sep 17 00:00:00 2001 From: Maciej Purski <m.purski@xxxxxxxxxxx> Date: Mon, 23 Apr 2018 16:33:40 +0200 Subject: [PATCH] regulator: core: Resolve coupled regulators On Odroid XU3/4 and other Exynos5422 based boards there is a case, that different devices on the board are supplied by different regulators with non-fixed voltages. If one of these devices temporarily requires higher voltage, there might occur a situation that the spread between two devices' voltages is so high, that there is a risk of changing 'high' and 'low' states on the interconnection between devices powered by those regulators. Fill coupling descriptor with data obtained from DTS using previously defined of_functions. Fail to register a regulator, if some data inconsistency occurs. If some coupled regulators are not yet registered, don't fail to register, but try to resolve them in late init call. Signed-off-by: Maciej Purski <m.purski@xxxxxxxxxxx> Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> --- drivers/regulator/core.c | 100 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 0ca941b53571..6ed568b96c0e 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -4129,6 +4129,96 @@ static int regulator_register_resolve_supply(struct device *dev, void *data) return 0; } +static int regulator_fill_coupling_array(struct regulator_dev *rdev) +{ + struct coupling_desc *c_desc = &rdev->coupling_desc; + int n_coupled = c_desc->n_coupled; + struct regulator_dev *c_rdev; + int i; + + for (i = 1; i < n_coupled; i++) { + /* already resolved */ + if (c_desc->coupled_rdevs[i]) + continue; + + c_rdev = of_parse_coupled_regulator(rdev, i - 1); + + if (c_rdev) { + c_desc->coupled_rdevs[i] = c_rdev; + c_desc->n_resolved++; + } + } + + if (rdev->coupling_desc.n_resolved < n_coupled) + return -1; + else + return 0; +} + +static int regulator_register_fill_coupling_array(struct device *dev, + void *data) +{ + struct regulator_dev *rdev = dev_to_rdev(dev); + + if (!IS_ENABLED(CONFIG_OF)) + return 0; + + if (regulator_fill_coupling_array(rdev)) + rdev_dbg(rdev, "unable to resolve coupling\n"); + + return 0; +} + +static int regulator_resolve_coupling(struct regulator_dev *rdev) +{ + int n_phandles; + + if (!IS_ENABLED(CONFIG_OF)) + n_phandles = 0; + else + n_phandles = of_get_n_coupled(rdev); + + if (n_phandles + 1 > MAX_COUPLED) { + rdev_err(rdev, "too many regulators coupled\n"); + return -EPERM; + } + + /* + * Every regulator should always have coupling descriptor filled with + * at least pointer to itself. + */ + rdev->coupling_desc.coupled_rdevs[0] = rdev; + rdev->coupling_desc.n_coupled = n_phandles + 1; + rdev->coupling_desc.n_resolved++; + + /* regulator isn't coupled */ + if (n_phandles == 0) + return 0; + + /* regulator, which can't change its voltage, can't be coupled */ + if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) { + rdev_err(rdev, "voltage operation not allowed\n"); + return -EPERM; + } + + if (rdev->constraints->max_spread <= 0) { + rdev_err(rdev, "wrong max_spread value\n"); + return -EPERM; + } + + if (!of_check_coupling_data(rdev)) + return -EPERM; + + /* + * After everything has been checked, try to fill rdevs array + * with pointers to regulators parsed from device tree. If some + * regulators are not registered yet, retry in late init call + */ + regulator_fill_coupling_array(rdev); + + return 0; +} + /** * regulator_register - register regulator * @regulator_desc: regulator to register @@ -4262,6 +4352,13 @@ regulator_register(const struct regulator_desc *regulator_desc, if (ret < 0) goto wash; + mutex_lock(®ulator_list_mutex); + ret = regulator_resolve_coupling(rdev); + mutex_unlock(®ulator_list_mutex); + + if (ret != 0) + goto wash; + /* add consumers devices */ if (init_data) { mutex_lock(®ulator_list_mutex); @@ -4756,6 +4853,9 @@ static int __init regulator_init_complete(void) class_for_each_device(®ulator_class, NULL, NULL, regulator_late_cleanup); + class_for_each_device(®ulator_class, NULL, NULL, + regulator_register_fill_coupling_array); + return 0; } late_initcall_sync(regulator_init_complete); -- 2.17.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
