regulator: add driver for MAX8660/8661

Tested with a MX25-based custom board.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

4 files changed, 575 insertions, 0 deletions

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 7cfdd65bebb4..9e0aa14dc6af 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -69,6 +69,13 @@ config REGULATOR_MAX1586
           regulator via I2C bus. The provided regulator is suitable
           for PXA27x chips to control VCC_CORE and VCC_USIM voltages.
 
+config REGULATOR_MAX8660
+        tristate "Maxim 8660/8661 voltage regulator"
+        depends on I2C
+        help
+          This driver controls a Maxim 8660/8661 voltage output
+          regulator via I2C bus.
+
 config REGULATOR_TWL4030
         bool "TI TWL4030/TWL5030/TWL6030/TPS695x0 PMIC"
         depends on TWL4030_CORE
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 9ae3cc44e668..12285e41beec 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_REGULATOR_BQ24022) += bq24022.o
 obj-$(CONFIG_REGULATOR_LP3971) += lp3971.o
 obj-$(CONFIG_REGULATOR_MAX1586) += max1586.o
 obj-$(CONFIG_REGULATOR_TWL4030) += twl-regulator.o
+obj-$(CONFIG_REGULATOR_MAX8660) += max8660.o
 obj-$(CONFIG_REGULATOR_WM831X) += wm831x-dcdc.o
 obj-$(CONFIG_REGULATOR_WM831X) += wm831x-isink.o
 obj-$(CONFIG_REGULATOR_WM831X) += wm831x-ldo.o
diff --git a/drivers/regulator/max8660.c b/drivers/regulator/max8660.c
new file mode 100644
index 000000000000..acc2fb7b6087
--- /dev/null
+++ b/drivers/regulator/max8660.c
@@ -0,0 +1,510 @@
+/*
+ * 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/regulator/max8660.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 */
+        struct regulator_dev *rdev[];
+};
+
+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_list(struct regulator_dev *rdev, unsigned selector)
+{
+        if (selector > MAX8660_DCDC_MAX_SEL)
+                return -EINVAL;
+        return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP;
+}
+
+static int max8660_dcdc_get(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 MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP;
+}
+
+static int max8660_dcdc_set(struct regulator_dev *rdev, int min_uV, int max_uV)
+{
+        struct max8660 *max8660 = rdev_get_drvdata(rdev);
+        u8 reg, selector, bits;
+        int ret;
+
+        if (min_uV < MAX8660_DCDC_MIN_UV || min_uV > MAX8660_DCDC_MAX_UV)
+                return -EINVAL;
+        if (max_uV < MAX8660_DCDC_MIN_UV || max_uV > MAX8660_DCDC_MAX_UV)
+                return -EINVAL;
+
+        selector = (min_uV - (MAX8660_DCDC_MIN_UV - MAX8660_DCDC_STEP + 1))
+                        / MAX8660_DCDC_STEP;
+
+        ret = max8660_dcdc_list(rdev, selector);
+        if (ret < 0 || ret > max_uV)
+                return -EINVAL;
+