--- /dev/null
+/*
+ * max8973-regulator.c -- Maxim max8973
+ *
+ * Regulator driver for MAXIM 8973 DC-DC step-down switching regulator.
+ *
+ * Copyright (c) 2012, NVIDIA Corporation.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ *
+ * 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.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; 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
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/max8973-regulator.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+
+/* Register definitions */
+#define MAX8973_VOUT 0x0
+#define MAX8973_VOUT_DVS 0x1
+#define MAX8973_CONTROL1 0x2
+#define MAX8973_CONTROL2 0x3
+#define MAX8973_CHIPID1 0x4
+#define MAX8973_CHIPID2 0x5
+
+#define MAX8973_MAX_VOUT_REG 2
+
+/* MAX8973_VOUT */
+#define MAX8973_VOUT_ENABLE BIT(7)
+#define MAX8973_VOUT_MASK 0x7F
+
+/* MAX8973_VOUT_DVS */
+#define MAX8973_DVS_VOUT_MASK 0x7F
+
+/* MAX8973_CONTROL1 */
+#define MAX8973_SNS_ENABLE BIT(7)
+#define MAX8973_FPWM_EN_M BIT(6)
+#define MAX8973_NFSR_ENABLE BIT(5)
+#define MAX8973_AD_ENABLE BIT(4)
+#define MAX8973_BIAS_ENABLE BIT(3)
+#define MAX8973_FREQSHIFT_9PER BIT(2)
+
+#define MAX8973_RAMP_12mV_PER_US 0x0
+#define MAX8973_RAMP_25mV_PER_US 0x1
+#define MAX8973_RAMP_50mV_PER_US 0x2
+#define MAX8973_RAMP_200mV_PER_US 0x3
+
+/* MAX8973_CONTROL2 */
+#define MAX8973_WDTMR_ENABLE BIT(6)
+#define MAX8973_DISCH_ENBABLE BIT(5)
+#define MAX8973_FT_ENABLE BIT(4)
+
+#define MAX8973_CKKADV_TRIP_DISABLE 0xC
+#define MAX8973_CKKADV_TRIP_75mV_PER_US 0x0
+#define MAX8973_CKKADV_TRIP_150mV_PER_US 0x4
+#define MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS 0x8
+#define MAX8973_CONTROL_CLKADV_TRIP_MASK 0x00030000
+
+#define MAX8973_INDUCTOR_MIN_30_PER 0x0
+#define MAX8973_INDUCTOR_NOMINAL 0x1
+#define MAX8973_INDUCTOR_PLUS_30_PER 0x2
+#define MAX8973_INDUCTOR_PLUS_60_PER 0x3
+#define MAX8973_CONTROL_INDUCTOR_VALUE_MASK 0x00300000
+
+#define MAX8973_MIN_VOLATGE 606250
+#define MAX8973_MAX_VOLATGE 1400000
+#define MAX8973_VOLATGE_STEP 6250
+#define MAX8973_BUCK_N_VOLTAGE 0x80
+
+/* Maxim 8973 chip information */
+struct max8973_chip {
+ struct device *dev;
+ struct regulator_desc desc;
+ struct regmap *regmap;
+ bool enable_external_control;
+ int dvs_gpio;
+ int lru_index[MAX8973_MAX_VOUT_REG];
+ int curr_vout_val[MAX8973_MAX_VOUT_REG];
+ int curr_vout_reg;
+ int curr_gpio_val;
+ bool valid_dvs_gpio;
+ struct regulator_ops ops;
+};
+
+/*
+ * find_voltage_set_register: Find new voltage configuration register (VOUT).
+ * The finding of the new VOUT register will be based on the LRU mechanism.
+ * Each VOUT register will have different voltage configured . This
+ * Function will look if any of the VOUT register have requested voltage set
+ * or not.
+ * - If it is already there then it will make that register as most
+ * recently used and return as found so that caller need not to set
+ * the VOUT register but need to set the proper gpios to select this
+ * VOUT register.
+ * - If requested voltage is not found then it will use the least
+ * recently mechanism to get new VOUT register for new configuration
+ * and will return not_found so that caller need to set new VOUT
+ * register and then gpios (both).
+ */
+static bool find_voltage_set_register(struct max8973_chip *tps,
+ int req_vsel, int *vout_reg, int *gpio_val)
+{
+ int i;
+ bool found = false;
+ int new_vout_reg = tps->lru_index[MAX8973_MAX_VOUT_REG - 1];
+ int found_index = MAX8973_MAX_VOUT_REG - 1;
+
+ for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i) {
+ if (tps->curr_vout_val[tps->lru_index[i]] == req_vsel) {
+ new_vout_reg = tps->lru_index[i];
+ found_index = i;
+ found = true;
+ goto update_lru_index;
+ }
+ }
+
+update_lru_index:
+ for (i = found_index; i > 0; i--)
+ tps->lru_index[i] = tps->lru_index[i - 1];
+
+ tps->lru_index[0] = new_vout_reg;
+ *gpio_val = new_vout_reg;
+ *vout_reg = MAX8973_VOUT + new_vout_reg;
+ return found;
+}
+
+static int max8973_dcdc_get_voltage_sel(struct regulator_dev *rdev)
+{
+ struct max8973_chip *max = rdev_get_drvdata(rdev);
+ unsigned int data;
+ int ret;
+
+ ret = regmap_read(max->regmap, max->curr_vout_reg, &data);
+ if (ret < 0) {
+ dev_err(max->dev, "register %d read failed, err = %d\n",
+ max->curr_vout_reg, ret);
+ return ret;
+ }
+ return data & MAX8973_VOUT_MASK;
+}
+
+static int max8973_dcdc_set_voltage_sel(struct regulator_dev *rdev,
+ unsigned vsel)
+{
+ struct max8973_chip *max = rdev_get_drvdata(rdev);
+ int ret;
+ bool found = false;
+ int vout_reg = max->curr_vout_reg;
+ int gpio_val = max->curr_gpio_val;
+
+ /*
+ * If gpios are available to select the VOUT register then least
+ * recently used register for new configuration.
+ */
+ if (max->valid_dvs_gpio)
+ found = find_voltage_set_register(max, vsel,
+ &vout_reg, &gpio_val);
+
+ if (!found) {
+ ret = regmap_update_bits(max->regmap, vout_reg,
+ MAX8973_VOUT_MASK, vsel);
+ if (ret < 0) {
+ dev_err(max->dev, "register %d update failed, err %d\n",
+ vout_reg, ret);
+ return ret;
+ }
+ max->curr_vout_reg = vout_reg;
+ max->curr_vout_val[gpio_val] = vsel;
+ }
+
+ /* Select proper VOUT register vio gpios */
+ if (max->valid_dvs_gpio) {
+ gpio_set_value_cansleep(max->dvs_gpio, gpio_val & 0x1);
+ max->curr_gpio_val = gpio_val;
+ }
+ return 0;
+}
+
+static int max8973_dcdc_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+ struct max8973_chip *max = rdev_get_drvdata(rdev);
+ int ret;
+ int pwm;
+
+ /* Enable force PWM mode in FAST mode only. */
+ switch (mode) {
+ case REGULATOR_MODE_FAST:
+ pwm = MAX8973_FPWM_EN_M;
+ break;
+
+ case REGULATOR_MODE_NORMAL:
+ pwm = 0;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ ret = regmap_update_bits(max->regmap, MAX8973_CONTROL1,
+ MAX8973_FPWM_EN_M, pwm);
+ if (ret < 0)
+ dev_err(max->dev, "register %d update failed, err %d\n",
+ MAX8973_CONTROL1, ret);
+ return ret;
+}
+
+static unsigned int max8973_dcdc_get_mode(struct regulator_dev *rdev)
+{
+ struct max8973_chip *max = rdev_get_drvdata(rdev);
+ unsigned int data;
+ int ret;
+
+ ret = regmap_read(max->regmap, MAX8973_CONTROL1, &data);
+ if (ret < 0) {
+ dev_err(max->dev, "register %d read failed, err %d\n",
+ MAX8973_CONTROL1, ret);
+ return ret;
+ }
+ return (data & MAX8973_FPWM_EN_M) ?
+ REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
+}
+
+static const struct regulator_ops max8973_dcdc_ops = {
+ .get_voltage_sel = max8973_dcdc_get_voltage_sel,
+ .set_voltage_sel = max8973_dcdc_set_voltage_sel,
+ .list_voltage = regulator_list_voltage_linear,
+ .set_mode = max8973_dcdc_set_mode,
+ .get_mode = max8973_dcdc_get_mode,
+};
+
+static int max8973_init_dcdc(struct max8973_chip *max,
+ struct max8973_regulator_platform_data *pdata)
+{
+ int ret;
+ uint8_t control1 = 0;
+ uint8_t control2 = 0;
+
+ if (pdata->control_flags & MAX8973_CONTROL_REMOTE_SENSE_ENABLE)
+ control1 |= MAX8973_SNS_ENABLE;
+
+ if (!(pdata->control_flags & MAX8973_CONTROL_FALLING_SLEW_RATE_ENABLE))
+ control1 |= MAX8973_NFSR_ENABLE;
+
+ if (pdata->control_flags & MAX8973_CONTROL_OUTPUT_ACTIVE_DISCH_ENABLE)
+ control1 |= MAX8973_AD_ENABLE;
+
+ if (pdata->control_flags & MAX8973_CONTROL_BIAS_ENABLE)
+ control1 |= MAX8973_BIAS_ENABLE;
+
+ if (pdata->control_flags & MAX8973_CONTROL_FREQ_SHIFT_9PER_ENABLE)
+ control1 |= MAX8973_FREQSHIFT_9PER;
+
+ /* Set ramp delay */
+ if (pdata->reg_init_data &&
+ pdata->reg_init_data->constraints.ramp_delay) {
+ if (pdata->reg_init_data->constraints.ramp_delay < 25000)
+ control1 |= MAX8973_RAMP_12mV_PER_US;
+ else if (pdata->reg_init_data->constraints.ramp_delay < 50000)
+ control1 |= MAX8973_RAMP_25mV_PER_US;
+ else if (pdata->reg_init_data->constraints.ramp_delay < 200000)
+ control1 |= MAX8973_RAMP_50mV_PER_US;
+ else
+ control1 |= MAX8973_RAMP_200mV_PER_US;
+ } else {
+ control1 |= MAX8973_RAMP_12mV_PER_US;
+ max->desc.ramp_delay = 12500;
+ }
+
+ if (!(pdata->control_flags & MAX8973_CONTROL_PULL_DOWN_ENABLE))
+ control2 |= MAX8973_DISCH_ENBABLE;
+
+ /* Clock advance trip configuration */
+ switch (pdata->control_flags & MAX8973_CONTROL_CLKADV_TRIP_MASK) {
+ case MAX8973_CONTROL_CLKADV_TRIP_DISABLED:
+ control2 |= MAX8973_CKKADV_TRIP_DISABLE;
+ break;
+
+ case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US:
+ control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US;
+ break;
+
+ case MAX8973_CONTROL_CLKADV_TRIP_150mV_PER_US:
+ control2 |= MAX8973_CKKADV_TRIP_150mV_PER_US;
+ break;
+
+ case MAX8973_CONTROL_CLKADV_TRIP_75mV_PER_US_HIST_DIS:
+ control2 |= MAX8973_CKKADV_TRIP_75mV_PER_US_HIST_DIS;
+ break;
+ }
+
+ /* Configure inductor value */
+ switch (pdata->control_flags & MAX8973_CONTROL_INDUCTOR_VALUE_MASK) {
+ case MAX8973_CONTROL_INDUCTOR_VALUE_NOMINAL:
+ control2 |= MAX8973_INDUCTOR_NOMINAL;
+ break;
+
+ case MAX8973_CONTROL_INDUCTOR_VALUE_MINUS_30_PER:
+ control2 |= MAX8973_INDUCTOR_MIN_30_PER;
+ break;
+
+ case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_30_PER:
+ control2 |= MAX8973_INDUCTOR_PLUS_30_PER;
+ break;
+
+ case MAX8973_CONTROL_INDUCTOR_VALUE_PLUS_60_PER:
+ control2 |= MAX8973_INDUCTOR_PLUS_60_PER;
+ break;
+ }
+
+ ret = regmap_write(max->regmap, MAX8973_CONTROL1, control1);
+ if (ret < 0) {
+ dev_err(max->dev, "register %d write failed, err = %d",
+ MAX8973_CONTROL1, ret);
+ return ret;
+ }
+
+ ret = regmap_write(max->regmap, MAX8973_CONTROL2, control2);
+ if (ret < 0) {
+ dev_err(max->dev, "register %d write failed, err = %d",
+ MAX8973_CONTROL2, ret);
+ return ret;
+ }
+
+ /* If external control is enabled then disable EN bit */
+ if (max->enable_external_control) {
+ ret = regmap_update_bits(max->regmap, MAX8973_VOUT,
+ MAX8973_VOUT_ENABLE, 0);
+ if (ret < 0)
+ dev_err(max->dev, "register %d update failed, err = %d",
+ MAX8973_VOUT, ret);
+ }
+ return ret;
+}
+
+static const struct regmap_config max8973_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = MAX8973_CHIPID2,
+ .cache_type = REGCACHE_RBTREE,
+};
+
+static int max8973_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct max8973_regulator_platform_data *pdata;
+ struct regulator_config config = { };
+ struct regulator_dev *rdev;
+ struct max8973_chip *max;
+ int ret;
+
+ pdata = dev_get_platdata(&client->dev);
+
+ if (!pdata && !client->dev.of_node) {
+ dev_err(&client->dev, "No Platform data");
+ return -EIO;
+ }
+
+ max = devm_kzalloc(&client->dev, sizeof(*max), GFP_KERNEL);
+ if (!max)
+ return -ENOMEM;
+
+ max->regmap = devm_regmap_init_i2c(client, &max8973_regmap_config);
+ if (IS_ERR(max->regmap)) {
+ ret = PTR_ERR(max->regmap);
+ dev_err(&client->dev, "regmap init failed, err %d\n", ret);
+ return ret;
+ }
+
+ i2c_set_clientdata(client, max);
+ max->ops = max8973_dcdc_ops;
+ max->dev = &client->dev;
+ max->desc.name = id->name;
+ max->desc.id = 0;
+ max->desc.ops = &max->ops;
+ max->desc.type = REGULATOR_VOLTAGE;
+ max->desc.owner = THIS_MODULE;
+ max->desc.min_uV = MAX8973_MIN_VOLATGE;
+ max->desc.uV_step = MAX8973_VOLATGE_STEP;
+ max->desc.n_voltages = MAX8973_BUCK_N_VOLTAGE;
+
+ if (!pdata || !pdata->enable_ext_control) {
+ max->desc.enable_reg = MAX8973_VOUT;
+ max->desc.enable_mask = MAX8973_VOUT_ENABLE;
+ max->ops.enable = regulator_enable_regmap;
+ max->ops.disable = regulator_disable_regmap;
+ max->ops.is_enabled = regulator_is_enabled_regmap;
+ }
+
+ if (pdata) {
+ max->dvs_gpio = pdata->dvs_gpio;
+ max->enable_external_control = pdata->enable_ext_control;
+ max->curr_gpio_val = pdata->dvs_def_state;
+ max->curr_vout_reg = MAX8973_VOUT + pdata->dvs_def_state;
+ } else {
+ max->dvs_gpio = -EINVAL;
+ max->curr_vout_reg = MAX8973_VOUT;
+ }
+
+ max->lru_index[0] = max->curr_vout_reg;
+
+ if (gpio_is_valid(max->dvs_gpio)) {
+ int gpio_flags;
+ int i;
+
+ gpio_flags = (pdata->dvs_def_state) ?
+ GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+ ret = devm_gpio_request_one(&client->dev, max->dvs_gpio,
+ gpio_flags, "max8973-dvs");
+ if (ret) {
+ dev_err(&client->dev,
+ "gpio_request for gpio %d failed, err = %d\n",
+ max->dvs_gpio, ret);
+ return ret;
+ }
+ max->valid_dvs_gpio = true;
+
+ /*
+ * Initialize the lru index with vout_reg id
+ * The index 0 will be most recently used and
+ * set with the max->curr_vout_reg */
+ for (i = 0; i < MAX8973_MAX_VOUT_REG; ++i)
+ max->lru_index[i] = i;
+ max->lru_index[0] = max->curr_vout_reg;
+ max->lru_index[max->curr_vout_reg] = 0;
+ } else {
+ max->valid_dvs_gpio = false;
+ }
+
+ if (pdata) {
+ ret = max8973_init_dcdc(max, pdata);
+ if (ret < 0) {
+ dev_err(max->dev, "Max8973 Init failed, err = %d\n", ret);
+ return ret;
+ }
+ }
+
+ config.dev = &client->dev;
+ config.init_data = pdata ? pdata->reg_init_data :
+ of_get_regulator_init_data(&client->dev, client->dev.of_node,
+ &max->desc);
+ config.driver_data = max;
+ config.of_node = client->dev.of_node;
+ config.regmap = max->regmap;
+
+ /* Register the regulators */
+ rdev = devm_regulator_register(&client->dev, &max->desc, &config);
+ if (IS_ERR(rdev)) {
+ ret = PTR_ERR(rdev);
+ dev_err(max->dev, "regulator register failed, err %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct i2c_device_id max8973_id[] = {
+ {.name = "max8973",},
+ {},
+};
+
+MODULE_DEVICE_TABLE(i2c, max8973_id);
+
+static struct i2c_driver max8973_i2c_driver = {
+ .driver = {
+ .name = "max8973",
+ .owner = THIS_MODULE,
+ },
+ .probe = max8973_probe,
+ .id_table = max8973_id,
+};
+
+static int __init max8973_init(void)
+{
+ return i2c_add_driver(&max8973_i2c_driver);
+}
+subsys_initcall(max8973_init);
+
+static void __exit max8973_cleanup(void)
+{
+ i2c_del_driver(&max8973_i2c_driver);
+}
+module_exit(max8973_cleanup);
+
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
+MODULE_DESCRIPTION("MAX8973 voltage regulator driver");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff