regulator: twl4030 regulators

Support most of the LDO regulators in the twl4030 family chips.
In the case of LDOs supporting MMC/SD, the voltage controls are
used; but in most other cases, the regulator framework is only
used to enable/disable a supplies, conserving power when a given
voltage rail is not needed.

The drivers/mfd/twl4030-core.c code already sets up the various
regulators according to board-specific configuration, and knows
that some chips don't provide the full set of voltage rails.

The omitted regulators are intended to be under hardware control,
such as during the hardware-mediated system powerup, powerdown,
and suspend states.  Unless/until software hooks are known to
be safe, they won't be exported here.

These regulators implement the new get_status() operation, but
can't realistically implement get_mode(); the status output is
effectively the result of a vote, with the relevant hardware
inputs not exposed.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

1 files changed, 511 insertions, 0 deletions

diff --git a/drivers/regulator/twl4030-regulator.c b/drivers/regulator/twl4030-regulator.c
new file mode 100644
index 000000000000..23f282670db5
--- /dev/null
+++ b/drivers/regulator/twl4030-regulator.c
@@ -0,0 +1,511 @@
+/*
+ * twl4030-regulator.c -- support regulators in twl4030 family chips
+ *
+ * Copyright (C) 2008 David Brownell
+ *
+ * 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/init.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/i2c/twl4030.h>
+
+
+/*
+ * The TWL4030/TW5030/TPS659x0 family chips include power management, a
+ * USB OTG transceiver, an RTC, ADC, PWM, and lots more.  Some versions
+ * include an audio codec, battery charger, and more voltage regulators.
+ * These chips are often used in OMAP-based systems.
+ *
+ * This driver implements software-based resource control for various
+ * voltage regulators.  This is usually augmented with state machine
+ * based control.
+ */
+
+struct twlreg_info {
+        /* start of regulator's PM_RECEIVER control register bank */
+        u8                      base;
+
+        /* twl4030 resource ID, for resource control state machine */
+        u8                      id;
+
+        /* voltage in mV = table[VSEL]; table_len must be a power-of-two */
+        u8                      table_len;
+        const u16               *table;
+
+        /* chip constraints on regulator behavior */
+        u16                     min_mV;
+        u16                     max_mV;
+
+        /* used by regulator core */
+        struct regulator_desc   desc;
+};
+
+
+/* LDO control registers ... offset is from the base of its register bank.
+ * The first three registers of all power resource banks help hardware to
+ * manage the various resource groups.
+ */
+#define VREG_GRP                0
+#define VREG_TYPE               1
+#define VREG_REMAP              2
+#define VREG_DEDICATED          3       /* LDO control */
+
+
+static inline int
+twl4030reg_read(struct twlreg_info *info, unsigned offset)
+{
+        u8 value;
+        int status;
+
+        status = twl4030_i2c_read_u8(TWL4030_MODULE_PM_RECEIVER,
+                        &value, info->base + offset);
+        return (status < 0) ? status : value;
+}
+
+static inline int
+twl4030reg_write(struct twlreg_info *info, unsigned offset, u8 value)
+{
+        return twl4030_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER,
+                        value, info->base + offset);
+}
+
+/*----------------------------------------------------------------------*/
+
+/* generic power resource operations, which work on all regulators */
+
+static int twl4030reg_grp(struct regulator_dev *rdev)
+{
+        return twl4030reg_read(rdev_get_drvdata(rdev), VREG_GRP);
+}
+
+/*
+ * Enable/disable regulators by joining/leaving the P1 (processor) group.
+ * We assume nobody else is updating the DEV_GRP registers.
+ */
+
+#define P3_GRP          BIT(7)          /* "peripherals" */
+#define P2_GRP          BIT(6)          /* secondary processor, modem, etc */
+#define P1_GRP          BIT(5)          /* CPU/Linux */
+
+static int twl4030reg_is_enabled(struct regulator_dev *rdev)
+{
+        int     state = twl4030reg_grp(rdev);
+
+        if (state < 0)
+                return state;
+
+        return (state & P1_GRP) != 0;
+}
+
+static int twl4030reg_enable(struct regulator_dev *rdev)
+{
+        struct twlreg_info      *info = rdev_get_drvdata(rdev);
+        int                     grp;
+
+        grp = twl4030reg_read(info, VREG_GRP);
+        if (grp < 0)
+                return grp;
+
+        grp |= P1_GRP;
+        return twl4030reg_write(info, VREG_GRP, grp);
+}
+
+static int twl4030reg_disable(struct regulator_dev *rdev)
+{
+        struct twlreg_info      *info = rdev_get_drvdata(rdev);
+        int                     grp;
+
+        grp = twl4030reg_read(info, VREG_GRP);
+        if (grp < 0)
+                return grp;
+
+        grp &= ~P1_GRP;
+        return twl4030reg_write(info, VREG_GRP, grp);
+}
+
+static int twl4030reg_get_status(struct regulator_dev *rdev)
+{
+        int     state = twl4030reg_grp(rdev);
+
+        if (state < 0)
+                return state;
+        state &= 0x0f;
+
+        /* assume state != WARM_RESET; we'd not be running...  */
+        if (!state)
+                return REGULATOR_STATUS_OFF;
+        return (state & BIT(3))
+                ? REGULATOR_STATUS_NORMAL
+                : REGULATOR_STATUS_STANDBY;
+}
+
+static int twl4030reg_set_mode(struct regulator_dev *rdev, unsigned mode)
+{
+        struct twlreg_info      *info = rdev_get_drvdata(rdev);
+        unsigned                message;
+        int                     status;
+
+        /* We can only set the mode through state machine commands... */
+        switch (mode) {
+        case REGULATOR_MODE_NORMAL:
+                message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_ACTIVE);
+                break;
+        case REGULATOR_MODE_STANDBY:
+                message = MSG_SINGULAR(DEV_GRP_P1, info->id, RES_STATE_SLEEP);
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        /* Ensure the resource is associated with some group */
+        status = twl4030reg_grp(rdev);
+        if (status < 0)
+                return status;
+        if (!(status & (P3_GRP | P2_GRP | P1_GRP)))
+                return -EACCES;
+
+        status = twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER,
+                        message >> 8, 0x15 /* PB_WORD_MSB */ );
+        if (status >= 0)
+                return status;
+
+        return twl4030_i2c_write_u8(TWL4030_MODULE_PM_MASTER,
+                        message, 0x16 /* PB_WORD_LSB */ );
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Support for adjustable-voltage LDOs uses a four bit (or less) voltage
+ * select field in its control register.   We use tables indexed by VSEL
+ * to record voltages in milliVolts.  (Accuracy is about three percent.)
+ *
+ * Note that VSEL values for VAUX2 changed in twl5030 and newer silicon;
+ * currently handled by listing two slightly different VAUX2 regulators,
+ * only one of which will be configured.
+ *
+ * VSEL values documented as "TI cannot support these values" are flagged
+ * in these tables as UNSUP() values; we normally won't assign them.
+ */
+#ifdef CONFIG_TWL4030_ALLOW_UNSUPPORTED
+#define UNSUP_MASK      0x0000
+#else
+#define UNSUP_MASK      0x8000
+#endif
+
+#define UNSUP(x)        (UNSUP_MASK | (x))
+#define IS_UNSUP(x)     (UNSUP_MASK & (x))
+#define LDO_MV(x)       (~UNSUP_MASK & (x))
+
+
+static const u16 VAUX1_VSEL_table[] = {
+        UNSUP(1500), UNSUP(1800), 2500, 2800,
+        3000, 3000, 3000, 3000,
+};
+static const u16 VAUX2_4030_VSEL_table[] = {
+        UNSUP(1000), UNSUP(1000), UNSUP(1200), 1300,
+        1500, 1800, UNSUP(1850), 2500,
+        UNSUP(2600), 2800, UNSUP(2850), UNSUP(3000),
+        UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
+};
+static const u16 VAUX2_VSEL_table[] = {
+        1700, 1700, 1900, 1300,
+        1500, 1800, 2000, 2500,
+        2100, 2800, 2200, 2300,
+        2400, 2400, 2400, 2400,
+};
+static const u16 VAUX3_VSEL_table[] = {
+        1500, 1800, 2500, 2800,
+        UNSUP(3000), UNSUP(3000), UNSUP(3000), UNSUP(3000),
+};
+static const u16 VAUX4_VSEL_table[] = {
+        700, 1000, 1200, UNSUP(1300),
+        1500, 1800, UNSUP(1850), 2500,
+};
+static const u16 VMMC1_VSEL_table[] = {
+        1850, 2850, 3000, 3150,
+};
+static const u16 VMMC2_VSEL_table[] = {
+        UNSUP(1000), UNSUP(1000), UNSUP(1200), UNSUP(1300),
+        UNSUP(1500), UNSUP(1800), 1850, UNSUP(2500),
+        2600, 2800, 2850, 3000,
+        3150, 3150, 3150, 3150,
+};
+static const u16 VPLL1_VSEL_table[] = {
+        1000, 1200, 1300, 1800,
+        UNSUP(2800), UNSUP(3000), UNSUP(3000), UNSUP(3000),
+};
+static const u16 VPLL2_VSEL_table[] = {
+        700, 1000, 1200, 1300,
+        UNSUP(1500), 1800, UNSUP(1850), UNSUP(2500),
+        UNSUP(2600), UNSUP(2800), UNSUP(2850), UNSUP(3000),
+        UNSUP(3150), UNSUP(3150), UNSUP(3150), UNSUP(3150),
+};
+static const u16 VSIM_VSEL_table[] = {
+        UNSUP(1000), UNSUP(1200), UNSUP(1300), 1800,
+        2800, 3000, 3000, 3000,
+};
+static const u16 VDAC_VSEL_table[] = {
+        1200, 1300, 1800, 1800,
+};
+
+
+static int
+twl4030ldo_set_voltage(struct regulator_dev *rdev, int min_uV, int max_uV)
+{
+        struct twlreg_info      *info = rdev_get_drvdata(rdev);
+        int                     vsel;
+
+        for (vsel = 0; vsel < info->table_len; vsel++) {
+                int mV = info->table[vsel];
+                int uV;
+
+                if (IS_UNSUP(mV))
+                        continue;
+                uV = LDO_MV(mV) * 1000;
+
+                /* use the first in-range value */
+                if (min_uV <= uV && uV <= max_uV)
+                        return twl4030reg_write(info, VREG_DEDICATED, vsel);
+        }
+
+        return -EDOM;
+}
+
+static int twl4030ldo_get_voltage(struct regulator_dev *rdev)
+{
+        struct twlreg_info      *info = rdev_get_drvdata(rdev);
+        int                     vsel = twl4030reg_read(info, VREG_DEDICATED);
+
+        if (vsel < 0)
+                return vsel;
+
+        vsel &= info->table_len - 1;
+        return LDO_MV(info->table[vsel]) * 1000;
+}
+
+static struct regulator_ops twl4030ldo_ops = {
+        .set_voltage    = twl4030ldo_set_voltage,
+        .get_voltage    = twl4030ldo_get_voltage,
+
+        .enable         = twl4030reg_enable,
+        .disable        = twl4030reg_disable,
+        .is_enabled     = twl4030reg_is_enabled,
+
+        .set_mode       = twl4030reg_set_mode,
+
+        .get_status     = twl4030reg_get_status,
+};
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Fixed voltage LDOs don't have a VSEL field to update.
+ */
+static int twl4030fixed_get_voltage(struct regulator_dev *rdev)
+{
+        struct twlreg_info      *info = rdev_get_drvdata(rdev);
+
+        return info->min_mV * 1000;
+}
+
+static struct regulator_ops twl4030fixed_ops = {
+        .get_voltage    = twl4030fixed_get_voltage,
+
+        .enable         = twl4030reg_enable,
+        .disable        = twl4030reg_disable,
+        .is_enabled     = twl4030reg_is_enabled,
+
+        .set_mode       = twl4030reg_set_mode,
+
+        .get_status     = twl4030reg_get_status,
+};
+
+/*----------------------------------------------------------------------*/
+
+#define TWL_ADJUSTABLE_LDO(label, offset, num) { \
+        .base = offset, \
+        .id = num, \
+        .table_len = ARRAY_SIZE(label##_VSEL_table), \
+        .table = label##_VSEL_table, \
+        .desc = { \
+                .name = #label, \
+                .id = TWL4030_REG_##label, \
+                .ops = &twl4030ldo_ops, \
+                .type = REGULATOR_VOLTAGE, \
+                .owner = THIS_MODULE, \
+                }, \
+        }
+
+#define TWL_FIXED_LDO(label, offset, mVolts, num) { \
+        .base = offset, \
+        .id = num, \
+        .min_mV = mVolts, \
+        .max_mV = mVolts, \
+        .desc = { \
+                .name = #label, \
+                .id = TWL4030_REG_##label, \
+                .ops = &twl4030fixed_ops, \
+                .type = REGULATOR_VOLTAGE, \
+                .owner = THIS_MODULE, \
+                }, \
+        }
+
+/*
+ * We list regulators here if systems need some level of
+ * software control over them after boot.
+ */
+static struct twlreg_info twl4030_regs[] = {
+        TWL_ADJUSTABLE_LDO(VAUX1, 0x17, 1),
+        TWL_ADJUSTABLE_LDO(VAUX2_4030, 0x1b, 2),
+        TWL_ADJUSTABLE_LDO(VAUX2, 0x1b, 2),
+        TWL_ADJUSTABLE_LDO(VAUX3, 0x1f, 3),
+        TWL_ADJUSTABLE_LDO(VAUX4, 0x23, 4),
+        TWL_ADJUSTABLE_LDO(VMMC1, 0x27, 5),
+        TWL_ADJUSTABLE_LDO(VMMC2, 0x2b, 6),
+        /*
+        TWL_ADJUSTABLE_LDO(VPLL1, 0x2f, 7),
+        TWL_ADJUSTABLE_LDO(VPLL2, 0x33, 8),
+        */
+        TWL_ADJUSTABLE_LDO(VSIM, 0x37, 9),
+        TWL_ADJUSTABLE_LDO(VDAC, 0x3b, 10),
+        /*
+        TWL_ADJUSTABLE_LDO(VINTANA1, 0x3f, 11),
+        TWL_ADJUSTABLE_LDO(VINTANA2, 0x43, 12),
+        TWL_ADJUSTABLE_LDO(VINTDIG, 0x47, 13),
+        TWL_SMPS(VIO, 0x4b, 14),
+        TWL_SMPS(VDD1, 0x55, 15),
+        TWL_SMPS(VDD2, 0x63, 16),
+         */
+        TWL_FIXED_LDO(VUSB1V5, 0x71, 1500, 17),
+        TWL_FIXED_LDO(VUSB1V8, 0x74, 1800, 18),
+        TWL_FIXED_LDO(VUSB3V1, 0x77, 3100, 19),
+        /* VUSBCP is managed *only* by the USB subchip */
+};
+
+static int twl4030reg_probe(struct platform_device *pdev)
+{
+        int                             i;
+        struct twlreg_info              *info;
+        struct regulator_init_data      *initdata;
+        struct regulation_constraints   *c;
+        struct regulator_dev            *rdev;
+        int                             min_uV, max_uV;
+
+        for (i = 0, info = NULL; i < ARRAY_SIZE(twl4030_regs); i++) {
+                if (twl4030_regs[i].desc.id != pdev->id)
+                        continue;
+                info = twl4030_regs + i;
+                min_uV = info->min_mV * 1000;
+                max_uV = info->max_mV * 1000;
+                break;
+        }
+        if (!info)
+                return -ENODEV;
+
+        initdata = pdev->dev.platform_data;
+        if (!initdata)
+                return -EINVAL;
+
+        /* Constrain board-specific capabilities according to what
+         * this driver and the chip itself can actually do.
+         */
+        c = &initdata->constraints;
+        if (!c->min_uV || c->min_uV < min_uV)
+                c->min_uV = min_uV;
+        if (!c->max_uV || c->max_uV > max_uV)
+                c->max_uV = max_uV;
+        c->valid_modes_mask &= REGULATOR_MODE_NORMAL | REGULATOR_MODE_STANDBY;
+        c->valid_ops_mask &= REGULATOR_CHANGE_VOLTAGE
+                                | REGULATOR_CHANGE_MODE
+                                | REGULATOR_CHANGE_STATUS;
+
+        rdev = regulator_register(&info->desc, &pdev->dev, initdata, info);
+        if (IS_ERR(rdev)) {
+                dev_err(&pdev->dev, "can't register %s, %ld\n",
+                                info->desc.name, PTR_ERR(rdev));
+                return PTR_ERR(rdev);
+        }
+        platform_set_drvdata(pdev, rdev);
+
+        /* NOTE:  many regulators support short-circuit IRQs (presentable
+         * as REGULATOR_OVER_CURRENT notifications?) configured via:
+         *  - SC_CONFIG
+         *  - SC_DETECT1 (vintana2, vmmc1/2, vaux1/2/3/4)
+         *  - SC_DETECT2 (vusb, vdac, vio, vdd1/2, vpll2)
+         *  - IT_CONFIG
+         */
+
+        return 0;
+}
+
+static int __devexit twl4030reg_remove(struct platform_device *pdev)
+{
+        regulator_unregister(platform_get_drvdata(pdev));
+        return 0;
+}
+
+MODULE_ALIAS("platform:twl4030_reg");
+
+static struct platform_driver twl4030reg_driver = {
+        .probe          = twl4030reg_probe,
+        .remove         = __devexit_p(twl4030reg_remove),
+        /* NOTE: short name, to work around driver model truncation of
+         * "twl4030_regulator.12" (and friends) to "twl4030_regulator.1".
+         */
+        .driver.name    = "twl4030_reg",
+        .driver.owner   = THIS_MODULE,
+};
+
+static int __init twl4030reg_init(void)
+{
+        unsigned i, j;
+
+        /* determine min/max voltage constraints, taking into account
+         * whether set_voltage() will use the "unsupported" settings
+         */
+        for (i = 0; i < ARRAY_SIZE(twl4030_regs); i++) {
+                struct twlreg_info      *info = twl4030_regs + i;
+                const u16               *table;
+
+                /* fixed-voltage regulators */
+                if (!info->table_len)
+                        continue;
+
+                /* LDO regulators: */
+                for (j = 0, table = info->table;
+                                j < info->table_len;
+                                j++, table++) {
+                        u16             mV = *table;
+
+                        if (IS_UNSUP(mV))
+                                continue;
+                        mV = LDO_MV(mV);
+
+                        if (info->min_mV == 0 || info->min_mV > mV)
+                                info->min_mV = mV;
+                        if (info->max_mV < mV)
+                                info->max_mV = mV;
+                }
+        }
+
+        return platform_driver_register(&twl4030reg_driver);
+}
+subsys_initcall(twl4030reg_init);
+
+static void __exit twl4030reg_exit(void)
+{
+        platform_driver_unregister(&twl4030reg_driver);
+}
+module_exit(twl4030reg_exit)
+
+MODULE_DESCRIPTION("TWL4030 regulator driver");
+MODULE_LICENSE("GPL");