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authorMark Brown <broonie@opensource.wolfsonmicro.com>2010-01-25 22:41:57 +0300
committerLiam Girdwood <lrg@slimlogic.co.uk>2010-03-03 17:49:25 +0300
commit69dc16c325bef32b0a1a1abf15ae4047174cafc1 (patch)
treebb41933b94da89526efabaead5d693c46d904b70 /drivers/regulator/wm8994-regulator.c
parenta71b797fdc672714bfff1fdc142042a95e97d7ba (diff)
downloadlinux-69dc16c325bef32b0a1a1abf15ae4047174cafc1.tar.xz
regulator: Add WM8994 regulator support
The WM8994 contains two LDOs with mixed hardware/software control to minimise the number of external supplies required while delivering optimal voltages to minimise power consumption. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Diffstat (limited to 'drivers/regulator/wm8994-regulator.c')
-rw-r--r--drivers/regulator/wm8994-regulator.c304
1 files changed, 304 insertions, 0 deletions
diff --git a/drivers/regulator/wm8994-regulator.c b/drivers/regulator/wm8994-regulator.c
new file mode 100644
index 000000000000..d09e018b3177
--- /dev/null
+++ b/drivers/regulator/wm8994-regulator.c
@@ -0,0 +1,304 @@
+/*
+ * wm8994-regulator.c -- Regulator driver for the WM8994
+ *
+ * Copyright 2009 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.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; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/gpio.h>
+
+#include <linux/mfd/wm8994/core.h>
+#include <linux/mfd/wm8994/registers.h>
+#include <linux/mfd/wm8994/pdata.h>
+
+struct wm8994_ldo {
+ int enable;
+ int is_enabled;
+ struct regulator_dev *regulator;
+ struct wm8994 *wm8994;
+};
+
+#define WM8994_LDO1_MAX_SELECTOR 0x7
+#define WM8994_LDO2_MAX_SELECTOR 0x3
+
+static int wm8994_ldo_enable(struct regulator_dev *rdev)
+{
+ struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
+
+ /* If we have no soft control assume that the LDO is always enabled. */
+ if (!ldo->enable)
+ return 0;
+
+ gpio_set_value(ldo->enable, 1);
+ ldo->is_enabled = 1;
+
+ return 0;
+}
+
+static int wm8994_ldo_disable(struct regulator_dev *rdev)
+{
+ struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
+
+ /* If we have no soft control assume that the LDO is always enabled. */
+ if (!ldo->enable)
+ return -EINVAL;
+
+ gpio_set_value(ldo->enable, 0);
+ ldo->is_enabled = 0;
+
+ return 0;
+}
+
+static int wm8994_ldo_is_enabled(struct regulator_dev *rdev)
+{
+ struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
+
+ return ldo->is_enabled;
+}
+
+static int wm8994_ldo_enable_time(struct regulator_dev *rdev)
+{
+ /* 3ms is fairly conservative but this shouldn't be too performance
+ * critical; can be tweaked per-system if required. */
+ return 3000;
+}
+
+static int wm8994_ldo1_list_voltage(struct regulator_dev *rdev,
+ unsigned int selector)
+{
+ if (selector > WM8994_LDO1_MAX_SELECTOR)
+ return -EINVAL;
+
+ return (selector * 100000) + 2400000;
+}
+
+static int wm8994_ldo1_get_voltage(struct regulator_dev *rdev)
+{
+ struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
+ int val;
+
+ val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_1);
+ if (val < 0)
+ return val;
+
+ val = (val & WM8994_LDO1_VSEL_MASK) >> WM8994_LDO1_VSEL_SHIFT;
+
+ return wm8994_ldo1_list_voltage(rdev, val);
+}
+
+static int wm8994_ldo1_set_voltage(struct regulator_dev *rdev,
+ int min_uV, int max_uV)
+{
+ struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
+ int selector, v;
+
+ selector = (min_uV - 2400000) / 100000;
+ v = wm8994_ldo1_list_voltage(rdev, selector);
+ if (v < 0 || v > max_uV)
+ return -EINVAL;
+
+ selector <<= WM8994_LDO1_VSEL_SHIFT;
+
+ return wm8994_set_bits(ldo->wm8994, WM8994_LDO_1,
+ WM8994_LDO1_VSEL_MASK, selector);
+}
+
+static struct regulator_ops wm8994_ldo1_ops = {
+ .enable = wm8994_ldo_enable,
+ .disable = wm8994_ldo_disable,
+ .is_enabled = wm8994_ldo_is_enabled,
+ .enable_time = wm8994_ldo_enable_time,
+
+ .list_voltage = wm8994_ldo1_list_voltage,
+ .get_voltage = wm8994_ldo1_get_voltage,
+ .set_voltage = wm8994_ldo1_set_voltage,
+};
+
+static int wm8994_ldo2_list_voltage(struct regulator_dev *rdev,
+ unsigned int selector)
+{
+ if (selector > WM8994_LDO2_MAX_SELECTOR)
+ return -EINVAL;
+
+ return (selector * 100000) + 900000;
+}
+
+static int wm8994_ldo2_get_voltage(struct regulator_dev *rdev)
+{
+ struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
+ int val;
+
+ val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_2);
+ if (val < 0)
+ return val;
+
+ val = (val & WM8994_LDO2_VSEL_MASK) >> WM8994_LDO2_VSEL_SHIFT;
+
+ return wm8994_ldo2_list_voltage(rdev, val);
+}
+
+static int wm8994_ldo2_set_voltage(struct regulator_dev *rdev,
+ int min_uV, int max_uV)
+{
+ struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
+ int selector, v;
+
+ selector = (min_uV - 900000) / 100000;
+ v = wm8994_ldo2_list_voltage(rdev, selector);
+ if (v < 0 || v > max_uV)
+ return -EINVAL;
+
+ selector <<= WM8994_LDO2_VSEL_SHIFT;
+
+ return wm8994_set_bits(ldo->wm8994, WM8994_LDO_2,
+ WM8994_LDO2_VSEL_MASK, selector);
+}
+
+static struct regulator_ops wm8994_ldo2_ops = {
+ .enable = wm8994_ldo_enable,
+ .disable = wm8994_ldo_disable,
+ .is_enabled = wm8994_ldo_is_enabled,
+ .enable_time = wm8994_ldo_enable_time,
+
+ .list_voltage = wm8994_ldo2_list_voltage,
+ .get_voltage = wm8994_ldo2_get_voltage,
+ .set_voltage = wm8994_ldo2_set_voltage,
+};
+
+static struct regulator_desc wm8994_ldo_desc[] = {
+ {
+ .name = "LDO1",
+ .id = 1,
+ .type = REGULATOR_VOLTAGE,
+ .n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
+ .ops = &wm8994_ldo1_ops,
+ .owner = THIS_MODULE,
+ },
+ {
+ .name = "LDO2",
+ .id = 2,
+ .type = REGULATOR_VOLTAGE,
+ .n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
+ .ops = &wm8994_ldo2_ops,
+ .owner = THIS_MODULE,
+ },
+};
+
+static __devinit int wm8994_ldo_probe(struct platform_device *pdev)
+{
+ struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
+ struct wm8994_pdata *pdata = wm8994->dev->platform_data;
+ int id = pdev->id % ARRAY_SIZE(pdata->ldo);
+ struct wm8994_ldo *ldo;
+ int ret;
+
+ dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
+
+ if (!pdata)
+ return -ENODEV;
+
+ ldo = kzalloc(sizeof(struct wm8994_ldo), GFP_KERNEL);
+ if (ldo == NULL) {
+ dev_err(&pdev->dev, "Unable to allocate private data\n");
+ return -ENOMEM;
+ }
+
+ ldo->wm8994 = wm8994;
+
+ ldo->is_enabled = 1;
+
+ if (pdata->ldo[id].enable && gpio_is_valid(pdata->ldo[id].enable)) {
+ ldo->enable = pdata->ldo[id].enable;
+
+ ret = gpio_request(ldo->enable, "WM8994 LDO enable");
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n",
+ ret);
+ goto err;
+ }
+
+ ret = gpio_direction_output(ldo->enable, ldo->is_enabled);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to set GPIO up: %d\n",
+ ret);
+ goto err_gpio;
+ }
+ }
+
+ ldo->regulator = regulator_register(&wm8994_ldo_desc[id], &pdev->dev,
+ pdata->ldo[id].init_data, ldo);
+ if (IS_ERR(ldo->regulator)) {
+ ret = PTR_ERR(ldo->regulator);
+ dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
+ id + 1, ret);
+ goto err_gpio;
+ }
+
+ platform_set_drvdata(pdev, ldo);
+
+ return 0;
+
+err_gpio:
+ if (gpio_is_valid(ldo->enable))
+ gpio_free(ldo->enable);
+err:
+ kfree(ldo);
+ return ret;
+}
+
+static __devexit int wm8994_ldo_remove(struct platform_device *pdev)
+{
+ struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
+
+ regulator_unregister(ldo->regulator);
+ if (gpio_is_valid(ldo->enable))
+ gpio_free(ldo->enable);
+ kfree(ldo);
+
+ return 0;
+}
+
+static struct platform_driver wm8994_ldo_driver = {
+ .probe = wm8994_ldo_probe,
+ .remove = __devexit_p(wm8994_ldo_remove),
+ .driver = {
+ .name = "wm8994-ldo",
+ },
+};
+
+static int __init wm8994_ldo_init(void)
+{
+ int ret;
+
+ ret = platform_driver_register(&wm8994_ldo_driver);
+ if (ret != 0)
+ pr_err("Failed to register Wm8994 GP LDO driver: %d\n", ret);
+
+ return ret;
+}
+subsys_initcall(wm8994_ldo_init);
+
+static void __exit wm8994_ldo_exit(void)
+{
+ platform_driver_unregister(&wm8994_ldo_driver);
+}
+module_exit(wm8994_ldo_exit);
+
+/* Module information */
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("WM8994 LDO driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm8994-ldo");