--- /dev/null
+/*
+ * 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 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 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",
+ .owner = THIS_MODULE,
+ },
+ .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");
Code Review / kvmfornfv.git / blobdiff