diff options
Diffstat (limited to 'drivers/regulator/ab3100.c')
| -rw-r--r-- | drivers/regulator/ab3100.c | 694 |
1 files changed, 694 insertions, 0 deletions
diff --git a/drivers/regulator/ab3100.c b/drivers/regulator/ab3100.c new file mode 100644 index 000000000000..156979d1f41e --- /dev/null +++ b/drivers/regulator/ab3100.c @@ -0,0 +1,694 @@ +/* + * drivers/regulator/ab3100.c + * + * Copyright (C) 2008-2009 ST-Ericsson AB + * License terms: GNU General Public License (GPL) version 2 + * Low-level control of the AB3100 IC Low Dropout (LDO) + * regulators, external regulator and buck converter + * Author: Mattias Wallin <mattias.wallin@stericsson.com> + * Author: Linus Walleij <linus.walleij@stericsson.com> + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/delay.h> +#include <linux/platform_device.h> +#include <linux/regulator/driver.h> +#include <linux/mfd/ab3100.h> + +/* LDO registers and some handy masking definitions for AB3100 */ +#define AB3100_LDO_A 0x40 +#define AB3100_LDO_C 0x41 +#define AB3100_LDO_D 0x42 +#define AB3100_LDO_E 0x43 +#define AB3100_LDO_E_SLEEP 0x44 +#define AB3100_LDO_F 0x45 +#define AB3100_LDO_G 0x46 +#define AB3100_LDO_H 0x47 +#define AB3100_LDO_H_SLEEP_MODE 0 +#define AB3100_LDO_H_SLEEP_EN 2 +#define AB3100_LDO_ON 4 +#define AB3100_LDO_H_VSEL_AC 5 +#define AB3100_LDO_K 0x48 +#define AB3100_LDO_EXT 0x49 +#define AB3100_BUCK 0x4A +#define AB3100_BUCK_SLEEP 0x4B +#define AB3100_REG_ON_MASK 0x10 + +/** + * struct ab3100_regulator + * A struct passed around the individual regulator functions + * @platform_device: platform device holding this regulator + * @ab3100: handle to the AB3100 parent chip + * @plfdata: AB3100 platform data passed in at probe time + * @regreg: regulator register number in the AB3100 + * @fixed_voltage: a fixed voltage for this regulator, if this + * 0 the voltages array is used instead. + * @typ_voltages: an array of available typical voltages for + * this regulator + * @voltages_len: length of the array of available voltages + */ +struct ab3100_regulator { + struct regulator_dev *rdev; + struct ab3100 *ab3100; + struct ab3100_platform_data *plfdata; + u8 regreg; + int fixed_voltage; + int const *typ_voltages; + u8 voltages_len; +}; + +/* The order in which registers are initialized */ +static const u8 ab3100_reg_init_order[AB3100_NUM_REGULATORS+2] = { + AB3100_LDO_A, + AB3100_LDO_C, + AB3100_LDO_E, + AB3100_LDO_E_SLEEP, + AB3100_LDO_F, + AB3100_LDO_G, + AB3100_LDO_H, + AB3100_LDO_K, + AB3100_LDO_EXT, + AB3100_BUCK, + AB3100_BUCK_SLEEP, + AB3100_LDO_D, +}; + +/* Preset (hardware defined) voltages for these regulators */ +#define LDO_A_VOLTAGE 2750000 +#define LDO_C_VOLTAGE 2650000 +#define LDO_D_VOLTAGE 2650000 + +static const int const ldo_e_buck_typ_voltages[] = { + 1800000, + 1400000, + 1300000, + 1200000, + 1100000, + 1050000, + 900000, +}; + +static const int const ldo_f_typ_voltages[] = { + 1800000, + 1400000, + 1300000, + 1200000, + 1100000, + 1050000, + 2500000, + 2650000, +}; + +static const int const ldo_g_typ_voltages[] = { + 2850000, + 2750000, + 1800000, + 1500000, +}; + +static const int const ldo_h_typ_voltages[] = { + 2750000, + 1800000, + 1500000, + 1200000, +}; + +static const int const ldo_k_typ_voltages[] = { + 2750000, + 1800000, +}; + + +/* The regulator devices */ +static struct ab3100_regulator +ab3100_regulators[AB3100_NUM_REGULATORS] = { + { + .regreg = AB3100_LDO_A, + .fixed_voltage = LDO_A_VOLTAGE, + }, + { + .regreg = AB3100_LDO_C, + .fixed_voltage = LDO_C_VOLTAGE, + }, + { + .regreg = AB3100_LDO_D, + .fixed_voltage = LDO_D_VOLTAGE, + }, + { + .regreg = AB3100_LDO_E, + .typ_voltages = ldo_e_buck_typ_voltages, + .voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages), + }, + { + .regreg = AB3100_LDO_F, + .typ_voltages = ldo_f_typ_voltages, + .voltages_len = ARRAY_SIZE(ldo_f_typ_voltages), + }, + { + .regreg = AB3100_LDO_G, + .typ_voltages = ldo_g_typ_voltages, + .voltages_len = ARRAY_SIZE(ldo_g_typ_voltages), + }, + { + .regreg = AB3100_LDO_H, + .typ_voltages = ldo_h_typ_voltages, + .voltages_len = ARRAY_SIZE(ldo_h_typ_voltages), + }, + { + .regreg = AB3100_LDO_K, + .typ_voltages = ldo_k_typ_voltages, + .voltages_len = ARRAY_SIZE(ldo_k_typ_voltages), + }, + { + .regreg = AB3100_LDO_EXT, + /* No voltages for the external regulator */ + }, + { + .regreg = AB3100_BUCK, + .typ_voltages = ldo_e_buck_typ_voltages, + .voltages_len = ARRAY_SIZE(ldo_e_buck_typ_voltages), + }, +}; + +/* + * General functions for enable, disable and is_enabled used for + * LDO: A,C,E,F,G,H,K,EXT and BUCK + */ +static int ab3100_enable_regulator(struct regulator_dev *reg) +{ + struct ab3100_regulator *abreg = reg->reg_data; + int err; + u8 regval; + + err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg, + ®val); + if (err) { + dev_warn(®->dev, "failed to get regid %d value\n", + abreg->regreg); + return err; + } + + /* The regulator is already on, no reason to go further */ + if (regval & AB3100_REG_ON_MASK) + return 0; + + regval |= AB3100_REG_ON_MASK; + + err = ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg, + regval); + if (err) { + dev_warn(®->dev, "failed to set regid %d value\n", + abreg->regreg); + return err; + } + + /* Per-regulator power on delay from spec */ + switch (abreg->regreg) { + case AB3100_LDO_A: /* Fallthrough */ + case AB3100_LDO_C: /* Fallthrough */ + case AB3100_LDO_D: /* Fallthrough */ + case AB3100_LDO_E: /* Fallthrough */ + case AB3100_LDO_H: /* Fallthrough */ + case AB3100_LDO_K: + udelay(200); + break; + case AB3100_LDO_F: + udelay(600); + break; + case AB3100_LDO_G: + udelay(400); + break; + case AB3100_BUCK: + mdelay(1); + break; + default: + break; + } + + return 0; +} + +static int ab3100_disable_regulator(struct regulator_dev *reg) +{ + struct ab3100_regulator *abreg = reg->reg_data; + int err; + u8 regval; + + /* + * LDO D is a special regulator. When it is disabled, the entire + * system is shut down. So this is handled specially. + */ + if (abreg->regreg == AB3100_LDO_D) { + int i; + + dev_info(®->dev, "disabling LDO D - shut down system\n"); + /* + * Set regulators to default values, ignore any errors, + * we're going DOWN + */ + for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) { + (void) ab3100_set_register_interruptible(abreg->ab3100, + ab3100_reg_init_order[i], + abreg->plfdata->reg_initvals[i]); + } + + /* Setting LDO D to 0x00 cuts the power to the SoC */ + return ab3100_set_register_interruptible(abreg->ab3100, + AB3100_LDO_D, 0x00U); + + } + + /* + * All other regulators are handled here + */ + err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg, + ®val); + if (err) { + dev_err(®->dev, "unable to get register 0x%x\n", + abreg->regreg); + return err; + } + regval &= ~AB3100_REG_ON_MASK; + return ab3100_set_register_interruptible(abreg->ab3100, abreg->regreg, + regval); +} + +static int ab3100_is_enabled_regulator(struct regulator_dev *reg) +{ + struct ab3100_regulator *abreg = reg->reg_data; + u8 regval; + int err; + + err = ab3100_get_register_interruptible(abreg->ab3100, abreg->regreg, + ®val); + if (err) { + dev_err(®->dev, "unable to get register 0x%x\n", + abreg->regreg); + return err; + } + + return regval & AB3100_REG_ON_MASK; +} + +static int ab3100_list_voltage_regulator(struct regulator_dev *reg, + unsigned selector) +{ + struct ab3100_regulator *abreg = reg->reg_data; + + if (selector > abreg->voltages_len) + return -EINVAL; + return abreg->typ_voltages[selector]; +} + +static int ab3100_get_voltage_regulator(struct regulator_dev *reg) +{ + struct ab3100_regulator *abreg = reg->reg_data; + u8 regval; + int err; + + /* Return the voltage for fixed regulators immediately */ + if (abreg->fixed_voltage) + return abreg->fixed_voltage; + + /* + * For variable types, read out setting and index into + * supplied voltage list. + */ + err = ab3100_get_register_interruptible(abreg->ab3100, + abreg->regreg, ®val); + if (err) { + dev_warn(®->dev, + "failed to get regulator value in register %02x\n", + abreg->regreg); + return err; + } + + /* The 3 highest bits index voltages */ + regval &= 0xE0; + regval >>= 5; + + if (regval > abreg->voltages_len) { + dev_err(®->dev, + "regulator register %02x contains an illegal voltage setting\n", + abreg->regreg); + return -EINVAL; + } + + return abreg->typ_voltages[regval]; +} + +static int ab3100_get_best_voltage_index(struct regulator_dev *reg, + int min_uV, int max_uV) +{ + struct ab3100_regulator *abreg = reg->reg_data; + int i; + int bestmatch; + int bestindex; + + /* + * Locate the minimum voltage fitting the criteria on + * this regulator. The switchable voltages are not + * in strict falling order so we need to check them + * all for the best match. + */ + bestmatch = INT_MAX; + bestindex = -1; + for (i = 0; i < abreg->voltages_len; i++) { + if (abreg->typ_voltages[i] <= max_uV && + abreg->typ_voltages[i] >= min_uV && + abreg->typ_voltages[i] < bestmatch) { + bestmatch = abreg->typ_voltages[i]; + bestindex = i; + } + } + + if (bestindex < 0) { + dev_warn(®->dev, "requested %d<=x<=%d uV, out of range!\n", + min_uV, max_uV); + return -EINVAL; + } + return bestindex; +} + +static int ab3100_set_voltage_regulator(struct regulator_dev *reg, + int min_uV, int max_uV) +{ + struct ab3100_regulator *abreg = reg->reg_data; + u8 regval; + int err; + int bestindex; + + bestindex = ab3100_get_best_voltage_index(reg, min_uV, max_uV); + if (bestindex < 0) + return bestindex; + + err = ab3100_get_register_interruptible(abreg->ab3100, + abreg->regreg, ®val); + if (err) { + dev_warn(®->dev, + "failed to get regulator register %02x\n", + abreg->regreg); + return err; + } + + /* The highest three bits control the variable regulators */ + regval &= ~0xE0; + regval |= (bestindex << 5); + + err = ab3100_set_register_interruptible(abreg->ab3100, + abreg->regreg, regval); + if (err) + dev_warn(®->dev, "failed to set regulator register %02x\n", + abreg->regreg); + + return err; +} + +static int ab3100_set_suspend_voltage_regulator(struct regulator_dev *reg, + int uV) +{ + struct ab3100_regulator *abreg = reg->reg_data; + u8 regval; + int err; + int bestindex; + u8 targetreg; + + if (abreg->regreg == AB3100_LDO_E) + targetreg = AB3100_LDO_E_SLEEP; + else if (abreg->regreg == AB3100_BUCK) + targetreg = AB3100_BUCK_SLEEP; + else + return -EINVAL; + + /* LDO E and BUCK have special suspend voltages you can set */ + bestindex = ab3100_get_best_voltage_index(reg, uV, uV); + + err = ab3100_get_register_interruptible(abreg->ab3100, + targetreg, ®val); + if (err) { + dev_warn(®->dev, + "failed to get regulator register %02x\n", + targetreg); + return err; + } + + /* The highest three bits control the variable regulators */ + regval &= ~0xE0; + regval |= (bestindex << 5); + + err = ab3100_set_register_interruptible(abreg->ab3100, + targetreg, regval); + if (err) + dev_warn(®->dev, "failed to set regulator register %02x\n", + abreg->regreg); + + return err; +} + +/* + * The external regulator can just define a fixed voltage. + */ +static int ab3100_get_voltage_regulator_external(struct regulator_dev *reg) +{ + struct ab3100_regulator *abreg = reg->reg_data; + + return abreg->plfdata->external_voltage; +} + +static struct regulator_ops regulator_ops_fixed = { + .enable = ab3100_enable_regulator, + .disable = ab3100_disable_regulator, + .is_enabled = ab3100_is_enabled_regulator, + .get_voltage = ab3100_get_voltage_regulator, +}; + +static struct regulator_ops regulator_ops_variable = { + .enable = ab3100_enable_regulator, + .disable = ab3100_disable_regulator, + .is_enabled = ab3100_is_enabled_regulator, + .get_voltage = ab3100_get_voltage_regulator, + .set_voltage = ab3100_set_voltage_regulator, + .list_voltage = ab3100_list_voltage_regulator, +}; + +static struct regulator_ops regulator_ops_variable_sleepable = { + .enable = ab3100_enable_regulator, + .disable = ab3100_disable_regulator, + .is_enabled = ab3100_is_enabled_regulator, + .get_voltage = ab3100_get_voltage_regulator, + .set_voltage = ab3100_set_voltage_regulator, + .set_suspend_voltage = ab3100_set_suspend_voltage_regulator, + .list_voltage = ab3100_list_voltage_regulator, +}; + +/* + * LDO EXT is an external regulator so it is really + * not possible to set any voltage locally here, AB3100 + * is an on/off switch plain an simple. The external + * voltage is defined in the board set-up if any. + */ +static struct regulator_ops regulator_ops_external = { + .enable = ab3100_enable_regulator, + .disable = ab3100_disable_regulator, + .is_enabled = ab3100_is_enabled_regulator, + .get_voltage = ab3100_get_voltage_regulator_external, +}; + +static struct regulator_desc +ab3100_regulator_desc[AB3100_NUM_REGULATORS] = { + { + .name = "LDO_A", + .id = AB3100_LDO_A, + .ops = ®ulator_ops_fixed, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "LDO_C", + .id = AB3100_LDO_C, + .ops = ®ulator_ops_fixed, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "LDO_D", + .id = AB3100_LDO_D, + .ops = ®ulator_ops_fixed, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "LDO_E", + .id = AB3100_LDO_E, + .ops = ®ulator_ops_variable_sleepable, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "LDO_F", + .id = AB3100_LDO_F, + .ops = ®ulator_ops_variable, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "LDO_G", + .id = AB3100_LDO_G, + .ops = ®ulator_ops_variable, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "LDO_H", + .id = AB3100_LDO_H, + .ops = ®ulator_ops_variable, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "LDO_K", + .id = AB3100_LDO_K, + .ops = ®ulator_ops_variable, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "LDO_EXT", + .id = AB3100_LDO_EXT, + .ops = ®ulator_ops_external, + .type = REGULATOR_VOLTAGE, + }, + { + .name = "BUCK", + .id = AB3100_BUCK, + .ops = ®ulator_ops_variable_sleepable, + .type = REGULATOR_VOLTAGE, + }, +}; + +/* + * NOTE: the following functions are regulators pluralis - it is the + * binding to the AB3100 core driver and the parent platform device + * for all the different regulators. + */ + +static int __init ab3100_regulators_probe(struct platform_device *pdev) +{ + struct ab3100_platform_data *plfdata = pdev->dev.platform_data; + struct ab3100 *ab3100 = platform_get_drvdata(pdev); + int err = 0; + u8 data; + int i; + + /* Check chip state */ + err = ab3100_get_register_interruptible(ab3100, + AB3100_LDO_D, &data); + if (err) { + dev_err(&pdev->dev, "could not read initial status of LDO_D\n"); + return err; + } + if (data & 0x10) + dev_notice(&pdev->dev, + "chip is already in active mode (Warm start)\n"); + else + dev_notice(&pdev->dev, + "chip is in inactive mode (Cold start)\n"); + + /* Set up regulators */ + for (i = 0; i < ARRAY_SIZE(ab3100_reg_init_order); i++) { + err = ab3100_set_register_interruptible(ab3100, + ab3100_reg_init_order[i], + plfdata->reg_initvals[i]); + if (err) { + dev_err(&pdev->dev, "regulator initialization failed with error %d\n", + err); + return err; + } + } + + if (err) { + dev_err(&pdev->dev, + "LDO D regulator initialization failed with error %d\n", + err); + return err; + } + + /* Register the regulators */ + for (i = 0; i < AB3100_NUM_REGULATORS; i++) { + struct ab3100_regulator *reg = &ab3100_regulators[i]; + struct regulator_dev *rdev; + + /* + * Initialize per-regulator struct. + * Inherit platform data, this comes down from the + * i2c boarddata, from the machine. So if you want to + * see what it looks like for a certain machine, go + * into the machine I2C setup. + */ + reg->ab3100 = ab3100; + reg->plfdata = plfdata; + + /* + * Register the regulator, pass around + * the ab3100_regulator struct + */ + rdev = regulator_register(&ab3100_regulator_desc[i], + &pdev->dev, + &plfdata->reg_constraints[i], + reg); + + if (IS_ERR(rdev)) { + err = PTR_ERR(rdev); + dev_err(&pdev->dev, + "%s: failed to register regulator %s err %d\n", + __func__, ab3100_regulator_desc[i].name, + err); + i--; + /* remove the already registered regulators */ + while (i > 0) { + regulator_unregister(ab3100_regulators[i].rdev); + i--; + } + return err; + } + + /* Then set a pointer back to the registered regulator */ + reg->rdev = rdev; + } + + return 0; +} + +static int __exit ab3100_regulators_remove(struct platform_device *pdev) +{ + int i; + + for (i = 0; i < AB3100_NUM_REGULATORS; i++) { + struct ab3100_regulator *reg = &ab3100_regulators[i]; + + regulator_unregister(reg->rdev); + } + return 0; +} + +static struct platform_driver ab3100_regulators_driver = { + .driver = { + .name = "ab3100-regulators", + .owner = THIS_MODULE, + }, + .probe = ab3100_regulators_probe, + .remove = __exit_p(ab3100_regulators_remove), +}; + +static __init int ab3100_regulators_init(void) +{ + return platform_driver_register(&ab3100_regulators_driver); +} + +static __exit void ab3100_regulators_exit(void) +{ + platform_driver_register(&ab3100_regulators_driver); +} + +subsys_initcall(ab3100_regulators_init); +module_exit(ab3100_regulators_exit); + +MODULE_AUTHOR("Mattias Wallin <mattias.wallin@stericsson.com>"); +MODULE_DESCRIPTION("AB3100 Regulator driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:ab3100-regulators"); |