hwmon: lis3: regulator control

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@nokia.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c
index 383a84938a9..159e402ddec 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>
@@ -257,10 +258,46 @@ 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);
 
@@ -283,6 +320,8 @@ 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);
 
@@ -674,6 +713,7 @@ 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);
@@ -753,6 +793,8 @@ 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");
@@ -762,6 +804,8 @@ 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;
         case WAI_3DC:
                 printk(KERN_INFO DRIVER_NAME ": 8 bits 3DC sensor found\n");
@@ -778,6 +822,14 @@ 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);