lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <20221126002243.37b1034d@slackpad.lan> Date: Sat, 26 Nov 2022 00:22:43 +0000 From: Andre Przywara <andre.przywara@....com> To: Samuel Holland <samuel@...lland.org> Cc: Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, Chen-Yu Tsai <wens@...e.org>, Jernej Skrabec <jernej.skrabec@...il.com>, Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Rob Herring <robh+dt@...nel.org>, Andrew Lunn <andrew@...n.ch>, Heiko Stuebner <heiko@...ech.de>, Maxime Ripard <mripard@...nel.org>, devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, linux-sunxi@...ts.linux.dev Subject: Re: [PATCH v4 2/4] regulator: sun20i: Add Allwinner D1 LDOs driver On Thu, 24 Nov 2022 22:01:10 -0600 Samuel Holland <samuel@...lland.org> wrote: Hi Samuel, > D1 contains two pairs of LDOs, "analog" LDOs and "system" LDOs. They are > similar and can share a driver, but only the system LDOs have a DT > binding defined so far. > > The system LDOs have a single linear range. The voltage step is not an > integer, so a custom .list_voltage is needed to get the rounding right. > > Signed-off-by: Samuel Holland <samuel@...lland.org> > --- > > Changes in v4: > - Drop the analog LDOs until the codec binding is ready > > Changes in v3: > - Adjust control flow in sun20i_regulator_get_regmap() for clarity > > Changes in v2: > - Use decimal numbers for .n_voltages instead of field widths > - Get the regmap from the parent device instead of a property/phandle > > drivers/regulator/Kconfig | 8 ++ > drivers/regulator/Makefile | 1 + > drivers/regulator/sun20i-regulator.c | 150 +++++++++++++++++++++++++++ > 3 files changed, 159 insertions(+) > create mode 100644 drivers/regulator/sun20i-regulator.c > > diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig > index 070e4403c6c2..8480532114c1 100644 > --- a/drivers/regulator/Kconfig > +++ b/drivers/regulator/Kconfig > @@ -1280,6 +1280,14 @@ config REGULATOR_STW481X_VMMC > This driver supports the internal VMMC regulator in the STw481x > PMIC chips. > > +config REGULATOR_SUN20I > + tristate "Allwinner D1 internal LDOs" > + depends on ARCH_SUNXI || COMPILE_TEST > + select MFD_SYSCON > + default ARCH_SUNXI > + help > + This driver supports the internal LDOs in the Allwinner D1 SoC. > + > config REGULATOR_SY7636A > tristate "Silergy SY7636A voltage regulator" > depends on MFD_SY7636A > diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile > index 5962307e1130..8e9b5a21123d 100644 > --- a/drivers/regulator/Makefile > +++ b/drivers/regulator/Makefile > @@ -150,6 +150,7 @@ obj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o > obj-$(CONFIG_REGULATOR_STM32_PWR) += stm32-pwr.o > obj-$(CONFIG_REGULATOR_STPMIC1) += stpmic1_regulator.o > obj-$(CONFIG_REGULATOR_STW481X_VMMC) += stw481x-vmmc.o > +obj-$(CONFIG_REGULATOR_SUN20I) += sun20i-regulator.o > obj-$(CONFIG_REGULATOR_SY7636A) += sy7636a-regulator.o > obj-$(CONFIG_REGULATOR_SY8106A) += sy8106a-regulator.o > obj-$(CONFIG_REGULATOR_SY8824X) += sy8824x.o > diff --git a/drivers/regulator/sun20i-regulator.c b/drivers/regulator/sun20i-regulator.c > new file mode 100644 > index 000000000000..031bcc3dee50 > --- /dev/null > +++ b/drivers/regulator/sun20i-regulator.c > @@ -0,0 +1,150 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +// > +// Copyright (c) 2021-2022 Samuel Holland <samuel@...lland.org> > +// > + > +#include <linux/mfd/syscon.h> > +#include <linux/module.h> > +#include <linux/of_device.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/regulator/driver.h> > + > +#define SUN20I_SYS_LDO_CTRL_REG 0x150 > + > +struct sun20i_regulator_data { > + const struct regulator_desc *descs; > + unsigned int ndescs; > +}; > + > +/* regulator_list_voltage_linear() modified for the non-integral uV_step. */ > +static int sun20i_d1_system_ldo_list_voltage(struct regulator_dev *rdev, > + unsigned int selector) > +{ > + const struct regulator_desc *desc = rdev->desc; > + unsigned int uV; > + > + if (selector >= desc->n_voltages) > + return -EINVAL; > + > + uV = desc->min_uV + (desc->uV_step * selector); > + > + /* Produce correctly-rounded absolute voltages. */ > + return uV + ((selector + 1 + (desc->min_uV % 4)) / 3); > +} > + > +static const struct regulator_ops sun20i_d1_system_ldo_ops = { > + .list_voltage = sun20i_d1_system_ldo_list_voltage, > + .map_voltage = regulator_map_voltage_ascend, > + .set_voltage_sel = regulator_set_voltage_sel_regmap, > + .get_voltage_sel = regulator_get_voltage_sel_regmap, > +}; > + > +static const struct regulator_desc sun20i_d1_system_ldo_descs[] = { > + { > + .name = "ldoa", > + .supply_name = "ldo-in", > + .of_match = "ldoa", > + .ops = &sun20i_d1_system_ldo_ops, > + .type = REGULATOR_VOLTAGE, > + .owner = THIS_MODULE, > + .n_voltages = 32, > + .min_uV = 1600000, > + .uV_step = 13333, /* repeating */ So while I see that those values are probably the closest we can with a simple linear algorithm, they first two values seem to be slightly off from those values in the manual: sel diff algor manual 0: 7 (1.600 - 1.593) 1: 6 (1.613 - 1.607) Oddly enough the rest of the values are spot on. I don't know if this really matters, or if the LDOs are actually accurate enough to that level of precision, or if it's a manual bug, or if we really care at all, but it might warrant some comment, I guess? I just got triggered by the min value not being the first value in the list. > + .vsel_reg = SUN20I_SYS_LDO_CTRL_REG, > + .vsel_mask = GENMASK(7, 0), > + }, > + { > + .name = "ldob", > + .supply_name = "ldo-in", > + .of_match = "ldob", > + .ops = &sun20i_d1_system_ldo_ops, > + .type = REGULATOR_VOLTAGE, > + .owner = THIS_MODULE, > + .n_voltages = 64, > + .min_uV = 1166666, > + .uV_step = 13333, /* repeating */ For LDOB it seems to be worse, as the second half is constantly off by what looks like 6.666mV: sel diff algor manual ... 32: 0 (1.593 - 1.593) 33: 0 (1.607 - 1.607) 34: -7 (1.620 - 1.627) 35: -7 (1.633 - 1.64) 36: -6 (1.647 - 1.653) ... 63: -6 (2.007 - 2.013) The first half is correct, though. Closer inspection reveals that everything with bit 5 set is exactly the same as LDOA. Maybe we can use that to our advantage? Cheers, Andre > + .vsel_reg = SUN20I_SYS_LDO_CTRL_REG, > + .vsel_mask = GENMASK(15, 8), > + }, > +}; > + > +static const struct sun20i_regulator_data sun20i_d1_system_ldos = { > + .descs = sun20i_d1_system_ldo_descs, > + .ndescs = ARRAY_SIZE(sun20i_d1_system_ldo_descs), > +}; > + > +static struct regmap *sun20i_regulator_get_regmap(struct device *dev) > +{ > + struct regmap *regmap; > + > + /* > + * First try the syscon interface. The system control device is not > + * compatible with "syscon", so fall back to getting the regmap from > + * its platform device. This is ugly, but required for devicetree > + * backward compatibility. > + */ > + regmap = syscon_node_to_regmap(dev->parent->of_node); > + if (!IS_ERR(regmap)) > + return regmap; > + > + regmap = dev_get_regmap(dev->parent, NULL); > + if (regmap) > + return regmap; > + > + return ERR_PTR(-EPROBE_DEFER); > +} > + > +static int sun20i_regulator_probe(struct platform_device *pdev) > +{ > + const struct sun20i_regulator_data *data; > + struct device *dev = &pdev->dev; > + struct regulator_config config; > + struct regmap *regmap; > + > + data = of_device_get_match_data(dev); > + if (!data) > + return -EINVAL; > + > + regmap = sun20i_regulator_get_regmap(dev); > + if (IS_ERR(regmap)) > + return dev_err_probe(dev, PTR_ERR(regmap), "Failed to get regmap\n"); > + > + config = (struct regulator_config) { > + .dev = dev, > + .regmap = regmap, > + }; > + > + for (unsigned int i = 0; i < data->ndescs; ++i) { > + const struct regulator_desc *desc = &data->descs[i]; > + struct regulator_dev *rdev; > + > + rdev = devm_regulator_register(dev, desc, &config); > + if (IS_ERR(rdev)) > + return PTR_ERR(rdev); > + } > + > + return 0; > +} > + > +static const struct of_device_id sun20i_regulator_of_match[] = { > + { > + .compatible = "allwinner,sun20i-d1-system-ldos", > + .data = &sun20i_d1_system_ldos, > + }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, sun20i_regulator_of_match); > + > +static struct platform_driver sun20i_regulator_driver = { > + .probe = sun20i_regulator_probe, > + .driver = { > + .name = "sun20i-regulator", > + .of_match_table = sun20i_regulator_of_match, > + }, > +}; > +module_platform_driver(sun20i_regulator_driver); > + > +MODULE_AUTHOR("Samuel Holland <samuel@...lland.org>"); > +MODULE_DESCRIPTION("Allwinner D1 internal LDO driver"); > +MODULE_LICENSE("GPL");
Powered by blists - more mailing lists