arch/arm/mach-ux500/board-u5500.c: calibrate ALS input voltage

Provide the support for auto calibration of ALS Zone boundaries based on
min/max ALS input voltage.

Signed-off-by: Shreshtha Kumar Sahu <shreshthakumar.sahu@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/leds/leds-lm3530.c b/drivers/leds/leds-lm3530.c
index 4d7ce76..3dd7090 100644 (file)
--- a/drivers/leds/leds-lm3530.c
+++ b/drivers/leds/leds-lm3530.c
@@ -68,17 +68,16 @@
 #define LM3530_ALS2_IMP_SHIFT          (4)
 
 /* Zone Boundary Register defaults */
-#define LM3530_DEF_ZB_0                        (0x33)
-#define LM3530_DEF_ZB_1                        (0x66)
-#define LM3530_DEF_ZB_2                        (0x99)
-#define LM3530_DEF_ZB_3                        (0xCC)
+#define LM3530_ALS_ZB_MAX              (4)
+#define LM3530_ALS_WINDOW_mV           (1000)
+#define LM3530_ALS_OFFSET_mV           (4)
 
 /* Zone Target Register defaults */
-#define LM3530_DEF_ZT_0                        (0x19)
-#define LM3530_DEF_ZT_1                        (0x33)
+#define LM3530_DEF_ZT_0                        (0x7F)
+#define LM3530_DEF_ZT_1                        (0x66)
 #define LM3530_DEF_ZT_2                        (0x4C)
-#define LM3530_DEF_ZT_3                        (0x66)
-#define LM3530_DEF_ZT_4                        (0x7F)
+#define LM3530_DEF_ZT_3                        (0x33)
+#define LM3530_DEF_ZT_4                        (0x19)
 
 struct lm3530_mode_map {
        const char *mode;
@@ -150,6 +149,8 @@ static int lm3530_init_registers(struct lm3530_data *drvdata)
        u8 als_imp_sel = 0;
        u8 brightness;
        u8 reg_val[LM3530_REG_MAX];
+       u8 zones[LM3530_ALS_ZB_MAX];
+       u32 als_vmin, als_vmax, als_vstep;
        struct lm3530_platform_data *pltfm = drvdata->pdata;
        struct i2c_client *client = drvdata->client;
 
@@ -161,6 +162,26 @@ static int lm3530_init_registers(struct lm3530_data *drvdata)
                gen_config |= (LM3530_ENABLE_I2C);
 
        if (drvdata->mode == LM3530_BL_MODE_ALS) {
+               if (pltfm->als_vmax == 0) {
+                       pltfm->als_vmin = als_vmin = 0;
+                       pltfm->als_vmin = als_vmax = LM3530_ALS_WINDOW_mV;
+               }
+
+               als_vmin = pltfm->als_vmin;
+               als_vmax = pltfm->als_vmax;
+
+               if ((als_vmax - als_vmin) > LM3530_ALS_WINDOW_mV)
+                       pltfm->als_vmax = als_vmax =
+                               als_vmin + LM3530_ALS_WINDOW_mV;
+
+               /* n zone boundary makes n+1 zones */
+               als_vstep = (als_vmax - als_vmin) / (LM3530_ALS_ZB_MAX + 1);
+
+               for (i = 0; i < LM3530_ALS_ZB_MAX; i++)
+                       zones[i] = (((als_vmin + LM3530_ALS_OFFSET_mV) +
+                                       als_vstep + (i * als_vstep)) * LED_FULL)
+                                       / 1000;
+
                als_config =
                        (pltfm->als_avrg_time << LM3530_ALS_AVG_TIME_SHIFT) |
                        (LM3530_ENABLE_ALS) |
@@ -169,6 +190,7 @@ static int lm3530_init_registers(struct lm3530_data *drvdata)
                als_imp_sel =
                        (pltfm->als1_resistor_sel << LM3530_ALS1_IMP_SHIFT) |
                        (pltfm->als2_resistor_sel << LM3530_ALS2_IMP_SHIFT);
+
        }
 
        if (drvdata->mode == LM3530_BL_MODE_PWM)
@@ -190,10 +212,10 @@ static int lm3530_init_registers(struct lm3530_data *drvdata)
        reg_val[3] = 0x00;              /* LM3530_ALS_ZONE_REG */
        reg_val[4] = als_imp_sel;       /* LM3530_ALS_IMP_SELECT */
        reg_val[5] = brightness;        /* LM3530_BRT_CTRL_REG */
-       reg_val[6] = LM3530_DEF_ZB_0;   /* LM3530_ALS_ZB0_REG */
-       reg_val[7] = LM3530_DEF_ZB_1;   /* LM3530_ALS_ZB1_REG */
-       reg_val[8] = LM3530_DEF_ZB_2;   /* LM3530_ALS_ZB2_REG */
-       reg_val[9] = LM3530_DEF_ZB_3;   /* LM3530_ALS_ZB3_REG */
+       reg_val[6] = zones[0];          /* LM3530_ALS_ZB0_REG */
+       reg_val[7] = zones[1];          /* LM3530_ALS_ZB1_REG */
+       reg_val[8] = zones[2];          /* LM3530_ALS_ZB2_REG */
+       reg_val[9] = zones[3];          /* LM3530_ALS_ZB3_REG */
        reg_val[10] = LM3530_DEF_ZT_0;  /* LM3530_ALS_Z0T_REG */
        reg_val[11] = LM3530_DEF_ZT_1;  /* LM3530_ALS_Z1T_REG */
        reg_val[12] = LM3530_DEF_ZT_2;  /* LM3530_ALS_Z2T_REG */
@@ -265,6 +287,24 @@ static void lm3530_brightness_set(struct led_classdev *led_cdev,
        }
 }
 
+static ssize_t lm3530_mode_get(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct i2c_client *client = container_of(
+                                       dev->parent, struct i2c_client, dev);
+       struct lm3530_data *drvdata = i2c_get_clientdata(client);
+       int i, len = 0;
+
+       for (i = 0; i < ARRAY_SIZE(mode_map); i++)
+               if (drvdata->mode == mode_map[i].mode_val)
+                       len += sprintf(buf + len, "[%s] ", mode_map[i].mode);
+               else
+                       len += sprintf(buf + len, "%s ", mode_map[i].mode);
+
+       len += sprintf(buf + len, "\n");
+
+       return len;
+}
 
 static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
                                   *attr, const char *buf, size_t size)
@@ -298,8 +338,7 @@ static ssize_t lm3530_mode_set(struct device *dev, struct device_attribute
 
        return sizeof(drvdata->mode);
 }
-
-static DEVICE_ATTR(mode, 0644, NULL, lm3530_mode_set);
+static DEVICE_ATTR(mode, 0644, lm3530_mode_get, lm3530_mode_set);
 
 static int __devinit lm3530_probe(struct i2c_client *client,
                           const struct i2c_device_id *id)

diff --git a/include/linux/led-lm3530.h b/include/linux/led-lm3530.h
index 58592fa..8eb1235 100644 (file)
--- a/include/linux/led-lm3530.h
+++ b/include/linux/led-lm3530.h
@@ -84,6 +84,8 @@ enum lm3530_als_mode {
  * @brt_ramp_rise: rate of rise of led current
  * @als1_resistor_sel: internal resistance from ALS1 input to ground
  * @als2_resistor_sel: internal resistance from ALS2 input to ground
+ * @als_vmin: als input voltage calibrated for max brightness in mV
+ * @als_vmax: als input voltage calibrated for min brightness in mV
  * @brt_val: brightness value (0-255)
  */
 struct lm3530_platform_data {
@@ -101,6 +103,9 @@ struct lm3530_platform_data {
        u8 als1_resistor_sel;
        u8 als2_resistor_sel;
 
+       u32 als_vmin;
+       u32 als_vmax;
+
        u8 brt_val;
 };