[PATCH 02/12] hwmon: lis3: regulator control

Samu Onkalo
2010-10-22T11:57:24Z

Based on pm_runtime control, turn lis3 regulators on and off.
Perform context save and restore on transitions.

Feature is optional and must be enabled in platform data.

Signed-off-by: Samu Onkalo <samu.p.onkalo-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
---
drivers/hwmon/lis3lv02d.c | 52 ++++++++++++++++++++++++++++++++++++++
drivers/hwmon/lis3lv02d.h | 12 +++++++++
drivers/hwmon/lis3lv02d_i2c.c | 55 ++++++++++++++++++++++++++++++++++++++++-
include/linux/lis3lv02d.h | 2 +
4 files changed, 120 insertions(+), 1 deletions(-)

diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c
index 412ddc3..ade6f3a 100644
--- a/drivers/hwmon/lis3lv02d.c
+++ b/drivers/hwmon/lis3lv02d.c
@@ -31,6 +31,7 @@
#include <linux/delay.h>
#include <linux/wait.h>
#include <linux/poll.h>
+#include <linux/slab.h>
#include <linux/freezer.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
@@ -223,10 +224,46 @@ fail:
return ret;
}

+/*
+ * Order of registers in the list affects to order of the restore process.
+ * Perhaps it is a good idea to set interrupt enable register as a last one
+ * after all other configurations
+ */
+static u8 lis3_wai8_regs[] = { FF_WU_CFG_1, FF_WU_THS_1, FF_WU_DURATION_1,
+ FF_WU_CFG_2, FF_WU_THS_2, FF_WU_DURATION_2,
+ CLICK_CFG, CLICK_SRC, CLICK_THSY_X, CLICK_THSZ,
+ CLICK_TIMELIMIT, CLICK_LATENCY, CLICK_WINDOW,
+ CTRL_REG1, CTRL_REG2, CTRL_REG3};
+
+static u8 lis3_wai12_regs[] = {FF_WU_CFG, FF_WU_THS_L, FF_WU_THS_H,
+ FF_WU_DURATION, DD_CFG, DD_THSI_L, DD_THSI_H,
+ DD_THSE_L, DD_THSE_H,
+ CTRL_REG1, CTRL_REG3, CTRL_REG2};
+
+static inline void lis3_context_save(struct lis3lv02d *lis3)
+{
+ int i;
+ for (i = 0; i < lis3->regs_size; i++)
+ lis3->read(lis3, lis3->regs[i], &lis3->reg_cache[i]);
+ lis3->regs_stored = true;
+}
+
+static inline void lis3_context_restore(struct lis3lv02d *lis3)
+{
+ int i;
+ if (lis3->regs_stored)
+ for (i = 0; i < lis3->regs_size; i++)
+ lis3->write(lis3, lis3->regs[i], lis3->reg_cache[i]);
+}
+
void lis3lv02d_poweroff(struct lis3lv02d *lis3)
{
+ if (lis3->reg_ctrl)
+ lis3_context_save(lis3);
/* disable X,Y,Z axis and power down */
lis3->write(lis3, CTRL_REG1, 0x00);
+ if (lis3->reg_ctrl)
+ lis3->reg_ctrl(lis3, LIS3_REG_OFF);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);

@@ -249,6 +286,8 @@ void lis3lv02d_poweron(struct lis3lv02d *lis3)
reg |= CTRL2_BDU;
lis3->write(lis3, CTRL_REG2, reg);
}
+ if (lis3->reg_ctrl)
+ lis3_context_restore(lis3);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweron);

@@ -640,6 +679,7 @@ int lis3lv02d_remove_fs(struct lis3lv02d *lis3)
pm_runtime_disable(lis3->pm_dev);
pm_runtime_set_suspended(lis3->pm_dev);
}
+ kfree(lis3->reg_cache);
return 0;
}
EXPORT_SYMBOL_GPL(lis3lv02d_remove_fs);
@@ -719,6 +759,8 @@ int lis3lv02d_init_device(struct lis3lv02d *dev)
dev->odrs = lis3_12_rates;
dev->odr_mask = CTRL1_DF0 | CTRL1_DF1;
dev->scale = LIS3_SENSITIVITY_12B;
+ dev->regs = lis3_wai12_regs;
+ dev->regs_size = ARRAY_SIZE(lis3_wai12_regs);
break;
case WAI_8B:
printk(KERN_INFO DRIVER_NAME ": 8 bits sensor found\n");
@@ -728,6 +770,8 @@ int lis3lv02d_init_device(struct lis3lv02d *dev)
dev->odrs = lis3_8_rates;
dev->odr_mask = CTRL1_DR;
dev->scale = LIS3_SENSITIVITY_8B;
+ dev->regs = lis3_wai8_regs;
+ dev->regs_size = ARRAY_SIZE(lis3_wai8_regs);
break;
default:
printk(KERN_ERR DRIVER_NAME
@@ -735,6 +779,14 @@ int lis3lv02d_init_device(struct lis3lv02d *dev)
return -EINVAL;
}

+ dev->reg_cache = kzalloc(max(sizeof(lis3_wai8_regs),
+ sizeof(lis3_wai12_regs)), GFP_KERNEL);
+
+ if (dev->reg_cache == NULL) {
+ printk(KERN_ERR DRIVER_NAME "out of memory\n");
+ return -ENOMEM;
+ }
+
mutex_init(&dev->mutex);

lis3lv02d_add_fs(dev);
diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h
index 3e8a208..7661e59 100644
--- a/drivers/hwmon/lis3lv02d.h
+++ b/drivers/hwmon/lis3lv02d.h
@@ -20,6 +20,7 @@
*/
#include <linux/platform_device.h>
#include <linux/input-polldev.h>
+#include <linux/regulator/consumer.h>

/*
* This driver tries to support the "digital" accelerometer chips from
@@ -206,6 +207,11 @@ enum lis3lv02d_click_src_8b {
CLICK_IA = 0x40,
};

+enum lis3lv02d_reg_state {
+ LIS3_REG_OFF = 0x00,
+ LIS3_REG_ON = 0x01,
+};
+
struct axis_conversion {
s8 x;
s8 y;
@@ -218,8 +224,13 @@ struct lis3lv02d {
int (*init) (struct lis3lv02d *lis3);
int (*write) (struct lis3lv02d *lis3, int reg, u8 val);
int (*read) (struct lis3lv02d *lis3, int reg, u8 *ret);
+ int (*reg_ctrl) (struct lis3lv02d *lis3, bool state);

int *odrs; /* Supported output data rates */
+ u8 *regs; /* Regs to store / restore */
+ int regs_size;
+ u8 *reg_cache;
+ bool regs_stored;
u8 odr_mask; /* ODR bit mask */
u8 whoami; /* indicates measurement precision */
s16 (*read_data) (struct lis3lv02d *lis3, int reg);
@@ -232,6 +243,7 @@ struct lis3lv02d {

struct input_polled_dev *idev; /* input device */
struct platform_device *pdev; /* platform device */
+ struct regulator_bulk_data regulators[2];
atomic_t count; /* interrupt count after last read */
struct axis_conversion ac; /* hw -> logical axis */
int mapped_btns[3];
diff --git a/drivers/hwmon/lis3lv02d_i2c.c b/drivers/hwmon/lis3lv02d_i2c.c
index 6e965d7..98983cc 100644
--- a/drivers/hwmon/lis3lv02d_i2c.c
+++ b/drivers/hwmon/lis3lv02d_i2c.c
@@ -30,10 +30,29 @@
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/pm_runtime.h>
+#include <linux/delay.h>
#include "lis3lv02d.h"

#define DRV_NAME "lis3lv02d_i2c"

+static const char reg_vdd[] = "Vdd";
+static const char reg_vdd_io[] = "Vdd_IO";
+
+static int lis3_reg_ctrl(struct lis3lv02d *lis3, bool state)
+{
+ int ret;
+ if (state == LIS3_REG_OFF) {
+ ret = regulator_bulk_disable(ARRAY_SIZE(lis3->regulators),
+ lis3->regulators);
+ } else {
+ ret = regulator_bulk_enable(ARRAY_SIZE(lis3->regulators),
+ lis3->regulators);
+ /* Chip needs time to wakeup. Not mentioned in datasheet */
+ usleep_range(10000, 20000);
+ }
+ return ret;
+}
+
static inline s32 lis3_i2c_write(struct lis3lv02d *lis3, int reg, u8 value)
{
struct i2c_client *c = lis3->bus_priv;
@@ -52,6 +71,13 @@ static int lis3_i2c_init(struct lis3lv02d *lis3)
u8 reg;
int ret;

+ if (lis3->reg_ctrl)
+ lis3_reg_ctrl(lis3, LIS3_REG_ON);
+
+ lis3->read(lis3, WHO_AM_I, &reg);
+ if (reg != lis3->whoami)
+ printk(KERN_ERR "lis3: power on failure\n");
+
/* power up the device */
ret = lis3->read(lis3, CTRL_REG1, &reg);
if (ret < 0)
@@ -73,6 +99,10 @@ static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
struct lis3lv02d_platform_data *pdata = client->dev.platform_data;

if (pdata) {
+ /* Regulator control is optional */
+ if (pdata->driver_features & LIS3_USE_REGULATOR_CTRL)
+ lis3_dev.reg_ctrl = lis3_reg_ctrl;
+
if (pdata->axis_x)
lis3lv02d_axis_map.x = pdata->axis_x;

@@ -89,6 +119,16 @@ static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
goto fail;
}

+ if (lis3_dev.reg_ctrl) {
+ lis3_dev.regulators[0].supply = reg_vdd;
+ lis3_dev.regulators[1].supply = reg_vdd_io;
+ ret = regulator_bulk_get(&client->dev,
+ ARRAY_SIZE(lis3_dev.regulators),
+ lis3_dev.regulators);
+ if (ret < 0)
+ goto fail;
+ }
+
lis3_dev.pdata = pdata;
lis3_dev.bus_priv = client;
lis3_dev.init = lis3_i2c_init;
@@ -99,21 +139,34 @@ static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
lis3_dev.pm_dev = &client->dev;

i2c_set_clientdata(client, &lis3_dev);
+
+ /* Provide power over the init call */
+ if (lis3_dev.reg_ctrl)
+ lis3_reg_ctrl(&lis3_dev, LIS3_REG_ON);
+
ret = lis3lv02d_init_device(&lis3_dev);
+
+ if (lis3_dev.reg_ctrl)
+ lis3_reg_ctrl(&lis3_dev, LIS3_REG_OFF);
fail:
return ret;
}

static int __devexit lis3lv02d_i2c_remove(struct i2c_client *client)
{
+ struct lis3lv02d *lis3 = i2c_get_clientdata(client);
struct lis3lv02d_platform_data *pdata = client->dev.platform_data;

if (pdata && pdata->release_resources)
pdata->release_resources();

lis3lv02d_joystick_disable();
+ lis3lv02d_remove_fs(&lis3_dev);

- return lis3lv02d_remove_fs(&lis3_dev);
+ if (lis3_dev.reg_ctrl)
+ regulator_bulk_free(ARRAY_SIZE(lis3->regulators),
+ lis3_dev.regulators);
+ return 0;
}

#ifdef CONFIG_PM
diff --git a/include/linux/lis3lv02d.h b/include/linux/lis3lv02d.h
index 0e8a346..c4a4a52 100644
--- a/include/linux/lis3lv02d.h
+++ b/include/linux/lis3lv02d.h
@@ -64,6 +64,8 @@ struct lis3lv02d_platform_data {
s8 axis_x;
s8 axis_y;
s8 axis_z;
+#define LIS3_USE_REGULATOR_CTRL 0x01
+ u16 driver_features;
int (*setup_resources)(void);
int (*release_resources)(void);
/* Limits for selftest are specified in chip data sheet */
--
1.6.0.4