mfd: Add ADC support to the DA9052/53 core

This patch adds ADC support to the DA9052/53 core.

Tested on smdkv6410 and i.mx53 QS boards.

Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

2 files changed, 159 insertions, 0 deletions

diff --git a/drivers/mfd/da9052-core.c b/drivers/mfd/da9052-core.c
index 7ff313fe9fb1..5036cf5fc077 100644
--- a/drivers/mfd/da9052-core.c
+++ b/drivers/mfd/da9052-core.c
@@ -318,6 +318,135 @@ static bool da9052_reg_volatile(struct device *dev, unsigned int reg)
         }
 }
 
+/*
+ * TBAT look-up table is computed from the R90 reg (8 bit register)
+ * reading as below. The battery temperature is in milliCentigrade
+ * TBAT = (1/(t1+1/298) - 273) * 1000 mC
+ * where t1 = (1/B)* ln(( ADCval * 2.5)/(R25*ITBAT*255))
+ * Default values are R25 = 10e3, B = 3380, ITBAT = 50e-6
+ * Example:
+ * R25=10E3, B=3380, ITBAT=50e-6, ADCVAL=62d calculates
+ * TBAT = 20015 mili degrees Centrigrade
+ *
+*/
+static const int32_t tbat_lookup[255] = {
+        183258, 144221, 124334, 111336, 101826, 94397, 88343, 83257,
+        78889, 75071, 71688, 68656, 65914, 63414, 61120, 59001,
+        570366, 55204, 53490, 51881, 50364, 48931, 47574, 46285,
+        45059, 43889, 42772, 41703, 40678, 39694, 38748, 37838,
+        36961, 36115, 35297, 34507, 33743, 33002, 32284, 31588,
+        30911, 30254, 29615, 28994, 28389, 27799, 27225, 26664,
+        26117, 25584, 25062, 24553, 24054, 23567, 23091, 22624,
+        22167, 21719, 21281, 20851, 20429, 20015, 19610, 19211,
+        18820, 18436, 18058, 17688, 17323, 16965, 16612, 16266,
+        15925, 15589, 15259, 14933, 14613, 14298, 13987, 13681,
+        13379, 13082, 12788, 12499, 12214, 11933, 11655, 11382,
+        11112, 10845, 10582, 10322, 10066, 9812, 9562, 9315,
+        9071, 8830, 8591, 8356, 8123, 7893, 7665, 7440,
+        7218, 6998, 6780, 6565, 6352, 6141, 5933, 5726,
+        5522, 5320, 5120, 4922, 4726, 4532, 4340, 4149,
+        3961, 3774, 3589, 3406, 3225, 3045, 2867, 2690,
+        2516, 2342, 2170, 2000, 1831, 1664, 1498, 1334,
+        1171, 1009, 849, 690, 532, 376, 221, 67,
+        -84, -236, -386, -535, -683, -830, -975, -1119,
+        -1263, -1405, -1546, -1686, -1825, -1964, -2101, -2237,
+        -2372, -2506, -2639, -2771, -2902, -3033, -3162, -3291,
+        -3418, -3545, -3671, -3796, -3920, -4044, -4166, -4288,
+        -4409, -4529, -4649, -4767, -4885, -5002, -5119, -5235,
+        -5349, -5464, -5577, -5690, -5802, -5913, -6024, -6134,
+        -6244, -6352, -6461, -6568, -6675, -6781, -6887, -6992,
+        -7096, -7200, -7303, -7406, -7508, -7609, -7710, -7810,
+        -7910, -8009, -8108, -8206, -8304, -8401, -8497, -8593,
+        -8689, -8784, -8878, -8972, -9066, -9159, -9251, -9343,
+        -9435, -9526, -9617, -9707, -9796, -9886, -9975, -10063,
+        -10151, -10238, -10325, -10412, -10839, -10923, -11007, -11090,
+        -11173, -11256, -11338, -11420, -11501, -11583, -11663, -11744,
+        -11823, -11903, -11982
+};
+
+static const u8 chan_mux[DA9052_ADC_VBBAT + 1] = {
+        [DA9052_ADC_VDDOUT]     = DA9052_ADC_MAN_MUXSEL_VDDOUT,
+        [DA9052_ADC_ICH]        = DA9052_ADC_MAN_MUXSEL_ICH,
+        [DA9052_ADC_TBAT]       = DA9052_ADC_MAN_MUXSEL_TBAT,
+        [DA9052_ADC_VBAT]       = DA9052_ADC_MAN_MUXSEL_VBAT,
+        [DA9052_ADC_IN4]        = DA9052_ADC_MAN_MUXSEL_AD4,
+        [DA9052_ADC_IN5]        = DA9052_ADC_MAN_MUXSEL_AD5,
+        [DA9052_ADC_IN6]        = DA9052_ADC_MAN_MUXSEL_AD6,
+        [DA9052_ADC_VBBAT]      = DA9052_ADC_MAN_MUXSEL_VBBAT
+};
+
+int da9052_adc_manual_read(struct da9052 *da9052, unsigned char channel)
+{
+        int ret;
+        unsigned short calc_data;
+        unsigned short data;
+        unsigned char mux_sel;
+
+        if (channel > DA9052_ADC_VBBAT)
+                return -EINVAL;
+
+        mutex_lock(&da9052->auxadc_lock);
+
+        /* Channel gets activated on enabling the Conversion bit */
+        mux_sel = chan_mux[channel] | DA9052_ADC_MAN_MAN_CONV;
+
+        ret = da9052_reg_write(da9052, DA9052_ADC_MAN_REG, mux_sel);
+        if (ret < 0)
+                goto err;
+
+        /* Wait for an interrupt */
+        if (!wait_for_completion_timeout(&da9052->done,
+                                         msecs_to_jiffies(500))) {
+                dev_err(da9052->dev,
+                        "timeout waiting for ADC conversion interrupt\n");
+                ret = -ETIMEDOUT;
+                goto err;
+        }
+
+        ret = da9052_reg_read(da9052, DA9052_ADC_RES_H_REG);
+        if (ret < 0)
+                goto err;
+
+        calc_data = (unsigned short)ret;
+        data = calc_data << 2;
+
+        ret = da9052_reg_read(da9052, DA9052_ADC_RES_L_REG);
+        if (ret < 0)
+                goto err;
+
+        calc_data = (unsigned short)(ret & DA9052_ADC_RES_LSB);
+        data |= calc_data;
+
+        ret = data;
+
+err:
+        mutex_unlock(&da9052->auxadc_lock);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(da9052_adc_manual_read);
+
+static irqreturn_t da9052_auxadc_irq(int irq, void *irq_data)
+{
+        struct da9052 *da9052 = irq_data;
+
+        complete(&da9052->done);
+
+        return IRQ_HANDLED;
+}
+
+int da9052_adc_read_temp(struct da9052 *da9052)
+{
+        int tbat;
+
+        tbat = da9052_reg_read(da9052, DA9052_TBAT_RES_REG);
+        if (tbat <= 0)
+                return tbat;
+
+        /* ARRAY_SIZE check is not needed since TBAT is a 8-bit register */
+        return tbat_lookup[tbat - 1];
+}
+EXPORT_SYMBOL_GPL(da9052_adc_read_temp);
+
 static struct resource da9052_rtc_resource = {
         .name = "ALM",
         .start = DA9052_IRQ_ALARM,
@@ -646,6 +775,9 @@ int __devinit da9052_device_init(struct da9052 *da9052, u8 chip_id)
         struct irq_desc *desc;
         int ret;
 
+        mutex_init(&da9052->auxadc_lock);
+        init_completion(&da9052->done);
+
         if (pdata && pdata->init != NULL)
                 pdata->init(da9052);
 
@@ -666,6 +798,12 @@ int __devinit da9052_device_init(struct da9052 *da9052, u8 chip_id)
         desc = irq_to_desc(da9052->chip_irq);
         da9052->irq_base = regmap_irq_chip_get_base(desc->action->dev_id);
 
+        ret = request_threaded_irq(DA9052_IRQ_ADC_EOM, NULL, da9052_auxadc_irq,
+                                   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                   "adc irq", da9052);
+        if (ret != 0)
+                dev_err(da9052->dev, "DA9052 ADC IRQ failed ret=%d\n", ret);
+
         ret = mfd_add_devices(da9052->dev, -1, da9052_subdev_info,
                               ARRAY_SIZE(da9052_subdev_info), NULL, 0);
         if (ret)
@@ -674,6 +812,7 @@ int __devinit da9052_device_init(struct da9052 *da9052, u8 chip_id)
         return 0;
 
 err:
+        free_irq(DA9052_IRQ_ADC_EOM, da9052);
         mfd_remove_devices(da9052->dev);
 regmap_err:
         return ret;
@@ -681,6 +820,7 @@ regmap_err:
 
 void da9052_device_exit(struct da9052 *da9052)
 {
+        free_irq(DA9052_IRQ_ADC_EOM, da9052);
         regmap_del_irq_chip(da9052->chip_irq,
                             irq_get_irq_data(da9052->irq_base)->chip_data);
         mfd_remove_devices(da9052->dev);
diff --git a/include/linux/mfd/da9052/da9052.h b/include/linux/mfd/da9052/da9052.h
index 7ffbd6e9e7fc..b990cca1d9ee 100644
--- a/include/linux/mfd/da9052/da9052.h
+++ b/include/linux/mfd/da9052/da9052.h
@@ -33,6 +33,18 @@
 
 #include <linux/mfd/da9052/reg.h>
 
+/* Common - HWMON Channel Definations */
+#define DA9052_ADC_VDDOUT       0
+#define DA9052_ADC_ICH          1
+#define DA9052_ADC_TBAT 2
+#define DA9052_ADC_VBAT 3
+#define DA9052_ADC_IN4          4
+#define DA9052_ADC_IN5          5
+#define DA9052_ADC_IN6          6
+#define DA9052_ADC_TSI          7
+#define DA9052_ADC_TJUNC        8
+#define DA9052_ADC_VBBAT        9
+
 #define DA9052_IRQ_DCIN 0
 #define DA9052_IRQ_VBUS 1
 #define DA9052_IRQ_DCINREM      2
@@ -79,12 +91,19 @@ struct da9052 {
         struct device *dev;
         struct regmap *regmap;
 
+        struct mutex auxadc_lock;
+        struct completion done;
+
         int irq_base;
         u8 chip_id;
 
         int chip_irq;
 };
 
+/* ADC API */
+int da9052_adc_manual_read(struct da9052 *da9052, unsigned char channel);
+int da9052_adc_read_temp(struct da9052 *da9052);
+
 /* Device I/O API */
 static inline int da9052_reg_read(struct da9052 *da9052, unsigned char reg)
 {