Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752779AbdGXDeH convert rfc822-to-8bit (ORCPT ); Sun, 23 Jul 2017 23:34:07 -0400 Received: from smtp.csie.ntu.edu.tw ([140.112.30.61]:53362 "EHLO smtp.csie.ntu.edu.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752092AbdGXDd6 (ORCPT ); Sun, 23 Jul 2017 23:33:58 -0400 MIME-Version: 1.0 In-Reply-To: References: <20170723102749.17323-1-icenowy@aosc.io> <20170723102749.17323-3-icenowy@aosc.io> From: Chen-Yu Tsai Date: Mon, 24 Jul 2017 11:33:33 +0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [linux-sunxi] [PATCH 02/10] regulator: add support for SY8106A regulator To: Icenowy Zheng Cc: Chen-Yu Tsai , Ondrej Jirman , devicetree , "open list:THERMAL" , linux-sunxi , linux-kernel , Liam Girdwood , Mark Brown , Carlo Caione , Maxime Ripard , linux-clk , linux-arm-kernel Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11875 Lines: 326 On Mon, Jul 24, 2017 at 11:18 AM, wrote: > 在 2017-07-24 11:03，Chen-Yu Tsai 写道： >> >> On Sun, Jul 23, 2017 at 6:27 PM, Icenowy Zheng wrote: >>> >>> From: Ondrej Jirman >>> >>> SY8106A is an I2C attached single output regulator made by Silergy Corp, >>> which is used on several Allwinner H3/H5 SBCs to control the power >>> supply of the ARM cores. >>> >>> Add a driver for it. >>> >>> Signed-off-by: Ondrej Jirman >>> [Icenowy: Change commit message] >>> Signed-off-by: Icenowy Zheng >>> --- >>> drivers/regulator/Kconfig | 8 +- >>> drivers/regulator/Makefile | 2 +- >>> drivers/regulator/sy8106a-regulator.c | 163 >>> ++++++++++++++++++++++++++++++++++ >>> 3 files changed, 171 insertions(+), 2 deletions(-) >>> create mode 100644 drivers/regulator/sy8106a-regulator.c >>> >>> diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig >>> index 99b9362331b5..1efa73e18d07 100644 >>> --- a/drivers/regulator/Kconfig >>> +++ b/drivers/regulator/Kconfig >>> @@ -764,6 +764,13 @@ config REGULATOR_STW481X_VMMC >>> This driver supports the internal VMMC regulator in the STw481x >>> PMIC chips. >>> >>> +config REGULATOR_SY8106A >>> + tristate "Silergy SY8106A regulator" >>> + depends on I2C && (OF || COMPILE_TEST) >>> + select REGMAP_I2C >>> + help >>> + This driver supports SY8106A single output regulator. >>> + >>> config REGULATOR_TPS51632 >>> tristate "TI TPS51632 Power Regulator" >>> depends on I2C >>> @@ -938,4 +945,3 @@ config REGULATOR_WM8994 >>> WM8994 CODEC. >>> >>> endif >>> - >>> diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile >>> index 95b1e86ae692..f5120252f86a 100644 >>> --- a/drivers/regulator/Makefile >>> +++ b/drivers/regulator/Makefile >>> @@ -95,6 +95,7 @@ obj-$(CONFIG_REGULATOR_S2MPS11) += s2mps11.o >>> obj-$(CONFIG_REGULATOR_S5M8767) += s5m8767.o >>> obj-$(CONFIG_REGULATOR_SKY81452) += sky81452-regulator.o >>> obj-$(CONFIG_REGULATOR_STW481X_VMMC) += stw481x-vmmc.o >>> +obj-$(CONFIG_REGULATOR_SY8106A) += sy8106a-regulator.o >>> obj-$(CONFIG_REGULATOR_TI_ABB) += ti-abb-regulator.o >>> obj-$(CONFIG_REGULATOR_TPS6105X) += tps6105x-regulator.o >>> obj-$(CONFIG_REGULATOR_TPS62360) += tps62360-regulator.o >>> @@ -120,5 +121,4 @@ obj-$(CONFIG_REGULATOR_WM8350) += wm8350-regulator.o >>> obj-$(CONFIG_REGULATOR_WM8400) += wm8400-regulator.o >>> obj-$(CONFIG_REGULATOR_WM8994) += wm8994-regulator.o >>> >>> - >>> ccflags-$(CONFIG_REGULATOR_DEBUG) += -DDEBUG >>> diff --git a/drivers/regulator/sy8106a-regulator.c >>> b/drivers/regulator/sy8106a-regulator.c >>> new file mode 100644 >>> index 000000000000..1df889f68b3d >>> --- /dev/null >>> +++ b/drivers/regulator/sy8106a-regulator.c >>> @@ -0,0 +1,163 @@ >>> +/* >>> + * sy8106a-regulator.c - Regulator device driver for SY8106A >>> + * >>> + * Copyright (C) 2016 Ondřej Jirman >>> + * >>> + * This program is free software; you can redistribute it and/or >>> + * modify it under the terms of the GNU Library General Public >>> + * License as published by the Free Software Foundation; either >>> + * version 2 of the License, or (at your option) any later version. >>> + * >>> + * This program is distributed in the hope that it will be useful, >>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >>> + * Library General Public License for more details. >>> + */ >>> + >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> +#include >>> + >>> +#define SY8106A_REG_VOUT1_SEL 0x01 >>> +#define SY8106A_REG_VOUT_COM 0x02 >>> +#define SY8106A_REG_VOUT1_SEL_MASK 0x7f >>> +#define SY8106A_DISABLE_REG BIT(0) >>> +#define SY8106A_GO_BIT BIT(7) >>> + >>> +struct sy8106a { >>> + struct regulator_dev *rdev; >>> + struct regmap *regmap; >>> +}; >>> + >>> +static const struct regmap_config sy8106a_regmap_config = { >>> + .reg_bits = 8, >>> + .val_bits = 8, >>> +}; >>> + >>> +static int sy8106a_set_voltage_sel(struct regulator_dev *rdev, unsigned >>> int sel) >>> +{ >>> + /* We use our set_voltage_sel in order to avoid unnecessary I2C >>> + * chatter, because the regulator_get_voltage_sel_regmap using >>> + * apply_bit would perform 4 unnecessary transfers instead of >>> one, >>> + * increasing the chance of error. >>> + */ >>> + return regmap_write(rdev->regmap, rdev->desc->vsel_reg, >>> + sel | SY8106A_GO_BIT); >> >> >> There should also be an explanation of what the "go bit" does. >> In this case it enables control of the voltage over I2C. >> >>> +} >>> + >>> +static const struct regulator_ops sy8106a_ops = { >>> + .is_enabled = regulator_is_enabled_regmap, >>> + .set_voltage_sel = sy8106a_set_voltage_sel, >>> + .set_voltage_time_sel = regulator_set_voltage_time_sel, >>> + .get_voltage_sel = regulator_get_voltage_sel_regmap, >>> + .list_voltage = regulator_list_voltage_linear, >> >> >> No enable/disable ops? >> >>> +}; >>> + >>> +/* Default limits measured in millivolts and milliamps */ >>> +#define SY8106A_MIN_MV 680 >>> +#define SY8106A_MAX_MV 1950 >>> +#define SY8106A_STEP_MV 10 >>> + >>> +static const struct regulator_desc sy8106a_reg = { >>> + .name = "SY8106A", >>> + .id = 0, >>> + .ops = &sy8106a_ops, >>> + .type = REGULATOR_VOLTAGE, >>> + .n_voltages = ((SY8106A_MAX_MV - SY8106A_MIN_MV) / >>> SY8106A_STEP_MV) + 1, >>> + .min_uV = (SY8106A_MIN_MV * 1000), >>> + .uV_step = (SY8106A_STEP_MV * 1000), >>> + .vsel_reg = SY8106A_REG_VOUT1_SEL, >>> + .vsel_mask = SY8106A_REG_VOUT1_SEL_MASK, >>> + .enable_reg = SY8106A_REG_VOUT_COM, >>> + .enable_mask = SY8106A_DISABLE_REG, >>> + .disable_val = SY8106A_DISABLE_REG, >>> + .enable_is_inverted = 1, >> >> >> As the regulator core helpers currently are, there is no way to disable >> this regulator. regulator_disable_regmap looks like: > > > By reading the current code, I think removing the disable_val variable will > just make it work -- when enabling, the enable_reg will be set to disable_val > (as enable_is_inverted is 1), and disable_val is defaultly 0; when disabling, > the enable_reg will be set to enable_mask (fallbacked from enable_val, which > is also the default value 0), and the regulator successfully get disabled. (Gmail is wrapping the lines :( ) enable_mask is set to SY8106A_DISABLE_REG, which equals disable_val here, which is not 0. This is correct, as it is the bit mask passed to regmap_update_bits. So no, it does not work. It seems quite a lot of drivers depend on this fallback behavior though. ChenYu > >> >> if (rdev->desc->enable_is_inverted) { >> val = rdev->desc->enable_val; >> if (!val) >> val = rdev->desc->enable_mask; >> } else { >> val = rdev->desc->disable_val; >> } >> >> return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg, >> rdev->desc->enable_mask, val); >> >> Note the fallback to enable_mask if enable_val is not set. The enable >> helper has a similar structure. This regulator uses an enable value >> of 0, and disable value of 1, it is impossible to get it right. As >> it is now, it doesn't really make sense to me. >> >> The code was introduced in ca5d1b3524b4 ("regulator: helpers: Modify >> helpers enabling multi-bit control"). I wonder if it was an unintended >> consequence of the change? (original author CC-ed) >> >>> + .owner = THIS_MODULE, >>> +}; >>> + >>> +/* >>> + * I2C driver interface functions >>> + */ >>> +static int sy8106a_i2c_probe(struct i2c_client *i2c, >>> + const struct i2c_device_id *id) >>> +{ >>> + struct sy8106a *chip; >>> + struct device *dev = &i2c->dev; >>> + struct regulator_dev *rdev = NULL; >>> + struct regulator_config config = { }; >>> + unsigned int selector; >>> + int error; >>> + >>> + chip = devm_kzalloc(&i2c->dev, sizeof(struct sy8106a), >>> GFP_KERNEL); >>> + if (!chip) >>> + return -ENOMEM; >>> + >>> + chip->regmap = devm_regmap_init_i2c(i2c, &sy8106a_regmap_config); >>> + if (IS_ERR(chip->regmap)) { >>> + error = PTR_ERR(chip->regmap); >>> + dev_err(&i2c->dev, "Failed to allocate register map: >>> %d\n", >>> + error); >>> + return error; >>> + } >>> + >>> + config.dev = &i2c->dev; >>> + config.regmap = chip->regmap; >>> + config.driver_data = chip; >>> + >>> + config.of_node = dev->of_node; >>> + config.init_data = of_get_regulator_init_data(dev, dev->of_node, >>> + &sy8106a_reg); >>> + >>> + if (!config.init_data) >>> + return -ENOMEM; >>> + >>> + /* Probe regulator */ >>> + error = regmap_read(chip->regmap, SY8106A_REG_VOUT1_SEL, >>> &selector); >>> + if (error) { >>> + dev_err(&i2c->dev, "Failed to read voltage at probe time: >>> %d\n", error); >>> + return error; >>> + } >>> + >>> + rdev = devm_regulator_register(&i2c->dev, &sy8106a_reg, &config); >>> + if (IS_ERR(rdev)) { >>> + error = PTR_ERR(rdev); >>> + dev_err(&i2c->dev, "Failed to register SY8106A regulator: >>> %d\n", error); >>> + return error; >>> + } >>> + >>> + chip->rdev = rdev; >>> + >>> + i2c_set_clientdata(i2c, chip); >>> + >>> + return 0; >>> +} >>> + >>> +static const struct of_device_id sy8106a_i2c_of_match[] = { >>> + { .compatible = "silergy,sy8106a" }, >>> + { }, >>> +}; >>> +MODULE_DEVICE_TABLE(of, sy8106a_i2c_of_match); >>> + >>> +static const struct i2c_device_id sy8106a_i2c_id[] = { >>> + { "sy8106a", 0 }, >>> + { }, >>> +}; >>> +MODULE_DEVICE_TABLE(i2c, sy8106a_i2c_id); >>> + >>> +static struct i2c_driver sy8106a_regulator_driver = { >>> + .driver = { >>> + .name = "sy8106a", >>> + .of_match_table = of_match_ptr(sy8106a_i2c_of_match), >>> + }, >>> + .probe = sy8106a_i2c_probe, >>> + .id_table = sy8106a_i2c_id, >>> +}; >>> + >>> +module_i2c_driver(sy8106a_regulator_driver); >>> + >>> +MODULE_AUTHOR("Ondřej Jirman "); >>> +MODULE_DESCRIPTION("Regulator device driver for Silergy SY8106A"); >>> +MODULE_LICENSE("GPL v2"); >> >> >> This should be "GPL", to match what the license at the very top says. >> >> Regards >> ChenYu >> >>> -- >>> 2.13.0 >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "linux-sunxi" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to linux-sunxi+unsubscribe@googlegroups.com. >>> For more options, visit https://groups.google.com/d/optout. >> >> >> _______________________________________________ >> linux-arm-kernel mailing list >> linux-arm-kernel@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > > > -- > You received this message because you are subscribed to the Google Groups > "linux-sunxi" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to linux-sunxi+unsubscribe@googlegroups.com. > For more options, visit https://groups.google.com/d/optout.