/* * max8660.c -- Voltage regulation for the Maxim 8660/8661 * * based on max1586.c and wm8400-regulator.c * * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; version 2 of the License. * * 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 General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 59 Temple * Place, Suite 330, Boston, MA 02111-1307 USA * * Some info: * * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf * * This chip is a bit nasty because it is a write-only device. Thus, the driver * uses shadow registers to keep track of its values. The main problem appears * to be the initialization: When Linux boots up, we cannot know if the chip is * in the default state or not, so we would have to pass such information in * platform_data. As this adds a bit of complexity to the driver, this is left * out for now until it is really needed. * * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2. * * If the driver is feature complete, it might be worth to check if one set of * functions for V3-V7 is sufficient. For maximum flexibility during * development, they are separated for now. * */ #include <linux/module.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/platform_device.h> #include <linux/regulator/driver.h> #include <linux/slab.h> #include <linux/regulator/max8660.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/regulator/of_regulator.h> #define MAX8660_DCDC_MIN_UV 725000 #define MAX8660_DCDC_MAX_UV 1800000 #define MAX8660_DCDC_STEP 25000 #define MAX8660_DCDC_MAX_SEL 0x2b #define MAX8660_LDO5_MIN_UV 1700000 #define MAX8660_LDO5_MAX_UV 2000000 #define MAX8660_LDO5_STEP 25000 #define MAX8660_LDO5_MAX_SEL 0x0c #define MAX8660_LDO67_MIN_UV 1800000 #define MAX8660_LDO67_MAX_UV 3300000 #define MAX8660_LDO67_STEP 100000 #define MAX8660_LDO67_MAX_SEL 0x0f enum { MAX8660_OVER1, MAX8660_OVER2, MAX8660_VCC1, MAX8660_ADTV1, MAX8660_ADTV2, MAX8660_SDTV1, MAX8660_SDTV2, MAX8660_MDTV1, MAX8660_MDTV2, MAX8660_L12VCR, MAX8660_FPWM, MAX8660_N_REGS, /* not a real register */ }; struct max8660 { struct i2c_client *client; u8 shadow_regs[MAX8660_N_REGS]; /* as chip is write only */ }; static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val) { static const u8 max8660_addresses[MAX8660_N_REGS] = { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 }; int ret; u8 reg_val = (max8660->shadow_regs[reg] & mask) | val; dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n", max8660_addresses[reg], reg_val); ret = i2c_smbus_write_byte_data(max8660->client, max8660_addresses[reg], reg_val); if (ret == 0) max8660->shadow_regs[reg] = reg_val; return ret; } /* * DCDC functions */ static int max8660_dcdc_is_enabled(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 val = max8660->shadow_regs[MAX8660_OVER1]; u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; return !!(val & mask); } static int max8660_dcdc_enable(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4; return max8660_write(max8660, MAX8660_OVER1, 0xff, bit); } static int max8660_dcdc_disable(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4; return max8660_write(max8660, MAX8660_OVER1, mask, 0); } static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; u8 selector = max8660->shadow_regs[reg]; return selector; } static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 reg, bits; int ret; reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2; ret = max8660_write(max8660, reg, 0, selector); if (ret) return ret; /* Select target voltage register and activate regulation */ bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30; return max8660_write(max8660, MAX8660_VCC1, 0xff, bits); } static struct regulator_ops max8660_dcdc_ops = { .is_enabled = max8660_dcdc_is_enabled, .list_voltage = regulator_list_voltage_linear, .map_voltage = regulator_map_voltage_linear, .set_voltage_sel = max8660_dcdc_set_voltage_sel, .get_voltage_sel = max8660_dcdc_get_voltage_sel, }; /* * LDO5 functions */ static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 selector = max8660->shadow_regs[MAX8660_MDTV2]; return selector; } static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector) { struct max8660 *max8660 = rdev_get_drvdata(rdev); int ret; ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector); if (ret) return ret; /* Select target voltage register and activate regulation */ return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0); } static const struct regulator_ops max8660_ldo5_ops = { .list_voltage = regulator_list_voltage_linear, .map_voltage = regulator_map_voltage_linear, .set_voltage_sel = max8660_ldo5_set_voltage_sel, .get_voltage_sel = max8660_ldo5_get_voltage_sel, }; /* * LDO67 functions */ static int max8660_ldo67_is_enabled(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 val = max8660->shadow_regs[MAX8660_OVER2]; u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; return !!(val & mask); } static int max8660_ldo67_enable(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4; return max8660_write(max8660, MAX8660_OVER2, 0xff, bit); } static int max8660_ldo67_disable(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4; return max8660_write(max8660, MAX8660_OVER2, mask, 0); } static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev) { struct max8660 *max8660 = rdev_get_drvdata(rdev); u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4; u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf; return selector; } static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev, unsigned int selector) { struct max8660 *max8660 = rdev_get_drvdata(rdev); if (rdev_get_id(rdev) == MAX8660_V6) return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector); else return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4); } static const struct regulator_ops max8660_ldo67_ops = { .is_enabled = max8660_ldo67_is_enabled, .enable = max8660_ldo67_enable, .disable = max8660_ldo67_disable, .list_voltage = regulator_list_voltage_linear, .map_voltage = regulator_map_voltage_linear, .get_voltage_sel = max8660_ldo67_get_voltage_sel, .set_voltage_sel = max8660_ldo67_set_voltage_sel, }; static const struct regulator_desc max8660_reg[] = { { .name = "V3(DCDC)", .id = MAX8660_V3, .ops = &max8660_dcdc_ops, .type = REGULATOR_VOLTAGE, .n_voltages = MAX8660_DCDC_MAX_SEL + 1, .owner = THIS_MODULE, .min_uV = MAX8660_DCDC_MIN_UV, .uV_step = MAX8660_DCDC_STEP, }, { .name = "V4(DCDC)", .id = MAX8660_V4, .ops = &max8660_dcdc_ops, .type = REGULATOR_VOLTAGE, .n_voltages = MAX8660_DCDC_MAX_SEL + 1, .owner = THIS_MODULE, .min_uV = MAX8660_DCDC_MIN_UV, .uV_step = MAX8660_DCDC_STEP, }, { .name = "V5(LDO)", .id = MAX8660_V5, .ops = &max8660_ldo5_ops, .type = REGULATOR_VOLTAGE, .n_voltages = MAX8660_LDO5_MAX_SEL + 1, .owner = THIS_MODULE, .min_uV = MAX8660_LDO5_MIN_UV, .uV_step = MAX8660_LDO5_STEP, }, { .name = "V6(LDO)", .id = MAX8660_V6, .ops = &max8660_ldo67_ops, .type = REGULATOR_VOLTAGE, .n_voltages = MAX8660_LDO67_MAX_SEL + 1, .owner = THIS_MODULE, .min_uV = MAX8660_LDO67_MIN_UV, .uV_step = MAX8660_LDO67_STEP, }, { .name = "V7(LDO)", .id = MAX8660_V7, .ops = &max8660_ldo67_ops, .type = REGULATOR_VOLTAGE, .n_voltages = MAX8660_LDO67_MAX_SEL + 1, .owner = THIS_MODULE, .min_uV = MAX8660_LDO67_MIN_UV, .uV_step = MAX8660_LDO67_STEP, }, }; enum { MAX8660 = 0, MAX8661 = 1, }; #ifdef CONFIG_OF static const struct of_device_id max8660_dt_ids[] = { { .compatible = "maxim,max8660", .data = (void *) MAX8660 }, { .compatible = "maxim,max8661", .data = (void *) MAX8661 }, { } }; MODULE_DEVICE_TABLE(of, max8660_dt_ids); static int max8660_pdata_from_dt(struct device *dev, struct device_node **of_node, struct max8660_platform_data *pdata) { int matched, i; struct device_node *np; struct max8660_subdev_data *sub; struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)] = { }; np = of_get_child_by_name(dev->of_node, "regulators"); if (!np) { dev_err(dev, "missing 'regulators' subnode in DT\n"); return -EINVAL; } for (i = 0; i < ARRAY_SIZE(rmatch); i++) rmatch[i].name = max8660_reg[i].name; matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch)); of_node_put(np); if (matched <= 0) return matched; pdata->subdevs = devm_kzalloc(dev, sizeof(struct max8660_subdev_data) * matched, GFP_KERNEL); if (!pdata->subdevs) return -ENOMEM; pdata->num_subdevs = matched; sub = pdata->subdevs; for (i = 0; i < matched; i++) { sub->id = i; sub->name = rmatch[i].name; sub->platform_data = rmatch[i].init_data; of_node[i] = rmatch[i].of_node; sub++; } return 0; } #else static inline int max8660_pdata_from_dt(struct device *dev, struct device_node **of_node, struct max8660_platform_data *pdata) { return 0; } #endif static int max8660_probe(struct i2c_client *client, const struct i2c_device_id *i2c_id) { struct device *dev = &client->dev; struct max8660_platform_data pdata_of, *pdata = dev_get_platdata(dev); struct regulator_config config = { }; struct max8660 *max8660; int boot_on, i, id, ret = -EINVAL; struct device_node *of_node[MAX8660_V_END]; unsigned long type; if (dev->of_node && !pdata) { const struct of_device_id *id; id = of_match_device(of_match_ptr(max8660_dt_ids), dev); if (!id) return -ENODEV; ret = max8660_pdata_from_dt(dev, of_node, &pdata_of); if (ret < 0) return ret; pdata = &pdata_of; type = (unsigned long) id->data; } else { type = i2c_id->driver_data; memset(of_node, 0, sizeof(of_node)); } if (pdata->num_subdevs > MAX8660_V_END) { dev_err(dev, "Too many regulators found!\n"); return -EINVAL; } max8660 = devm_kzalloc(dev, sizeof(struct max8660), GFP_KERNEL); if (!max8660) return -ENOMEM; max8660->client = client; if (pdata->en34_is_high) { /* Simulate always on */ max8660->shadow_regs[MAX8660_OVER1] = 5; } else { /* Otherwise devices can be toggled via software */ max8660_dcdc_ops.enable = max8660_dcdc_enable; max8660_dcdc_ops.disable = max8660_dcdc_disable; } /* * First, set up shadow registers to prevent glitches. As some * registers are shared between regulators, everything must be properly * set up for all regulators in advance. */ max8660->shadow_regs[MAX8660_ADTV1] = max8660->shadow_regs[MAX8660_ADTV2] = max8660->shadow_regs[MAX8660_SDTV1] = max8660->shadow_regs[MAX8660_SDTV2] = 0x1b; max8660->shadow_regs[MAX8660_MDTV1] = max8660->shadow_regs[MAX8660_MDTV2] = 0x04; for (i = 0; i < pdata->num_subdevs; i++) { if (!pdata->subdevs[i].platform_data) boot_on = false; else boot_on = pdata->subdevs[i].platform_data->constraints.boot_on; switch (pdata->subdevs[i].id) { case MAX8660_V3: if (boot_on) max8660->shadow_regs[MAX8660_OVER1] |= 1; break; case MAX8660_V4: if (boot_on) max8660->shadow_regs[MAX8660_OVER1] |= 4; break; case MAX8660_V5: break; case MAX8660_V6: if (boot_on) max8660->shadow_regs[MAX8660_OVER2] |= 2; break; case MAX8660_V7: if (type == MAX8661) { dev_err(dev, "Regulator not on this chip!\n"); return -EINVAL; } if (boot_on) max8660->shadow_regs[MAX8660_OVER2] |= 4; break; default: dev_err(dev, "invalid regulator %s\n", pdata->subdevs[i].name); return ret; } } /* Finally register devices */ for (i = 0; i < pdata->num_subdevs; i++) { struct regulator_dev *rdev; id = pdata->subdevs[i].id; config.dev = dev; config.init_data = pdata->subdevs[i].platform_data; config.of_node = of_node[i]; config.driver_data = max8660; rdev = devm_regulator_register(&client->dev, &max8660_reg[id], &config); if (IS_ERR(rdev)) { ret = PTR_ERR(rdev); dev_err(&client->dev, "failed to register %s\n", max8660_reg[id].name); return PTR_ERR(rdev); } } i2c_set_clientdata(client, max8660); return 0; } static const struct i2c_device_id max8660_id[] = { { .name = "max8660", .driver_data = MAX8660 }, { .name = "max8661", .driver_data = MAX8661 }, { } }; MODULE_DEVICE_TABLE(i2c, max8660_id); static struct i2c_driver max8660_driver = { .probe = max8660_probe, .driver = { .name = "max8660", }, .id_table = max8660_id, }; static int __init max8660_init(void) { return i2c_add_driver(&max8660_driver); } subsys_initcall(max8660_init); static void __exit max8660_exit(void) { i2c_del_driver(&max8660_driver); } module_exit(max8660_exit); /* Module information */ MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver"); MODULE_AUTHOR("Wolfram Sang"); MODULE_LICENSE("GPL v2");