This patch adds basic driver implementation for Broadcom's
static adc controller used in iProc SoC's family.

Signed-off-by: Raveendra Padasalagi <raveendra.padasal...@broadcom.com>
Reviewed-by: Ray Jui <ray....@broadcom.com>
Reviewed-by: Scott Branden <scott.bran...@broadcom.com>
---
 drivers/iio/adc/Kconfig         |  12 +
 drivers/iio/adc/Makefile        |   1 +
 drivers/iio/adc/bcm_iproc_adc.c | 648 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 661 insertions(+)
 create mode 100644 drivers/iio/adc/bcm_iproc_adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 25378c5..1de31bd 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -153,6 +153,18 @@ config AXP288_ADC
          To compile this driver as a module, choose M here: the module will be
          called axp288_adc.
 
+config BCM_IPROC_ADC
+       tristate "Broadcom IPROC ADC driver"
+       depends on ARCH_BCM_IPROC || COMPILE_TEST
+       depends on MFD_SYSCON
+       default ARCH_BCM_CYGNUS
+       help
+         Say Y here if you want to add support for the Broadcom static
+         ADC driver.
+
+         Broadcom iProc ADC driver. Broadcom iProc ADC controller has 8
+         channels. The driver allows the user to read voltage values.
+
 config BERLIN2_ADC
        tristate "Marvell Berlin2 ADC driver"
        depends on ARCH_BERLIN
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 38638d4..0ba0d50 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_AD799X) += ad799x.o
 obj-$(CONFIG_AT91_ADC) += at91_adc.o
 obj-$(CONFIG_AT91_SAMA5D2_ADC) += at91-sama5d2_adc.o
 obj-$(CONFIG_AXP288_ADC) += axp288_adc.o
+obj-$(CONFIG_BCM_IPROC_ADC) += bcm_iproc_adc.o
 obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o
 obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
 obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
diff --git a/drivers/iio/adc/bcm_iproc_adc.c b/drivers/iio/adc/bcm_iproc_adc.c
new file mode 100644
index 0000000..e10f6ce
--- /dev/null
+++ b/drivers/iio/adc/bcm_iproc_adc.c
@@ -0,0 +1,648 @@
+/*
+ * Copyright 2016 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation (the "GPL").
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License version 2 (GPLv2) for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 (GPLv2) along with this source code.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <linux/iio/iio.h>
+
+/* Below Register's are common to IPROC ADC and Touchscreen IP */
+#define IPROC_REGCTL1                  0x00
+#define IPROC_REGCTL2                  0x04
+#define IPROC_INTERRUPT_THRES          0x08
+#define IPROC_INTERRUPT_MASK           0x0c
+#define IPROC_INTERRUPT_STATUS         0x10
+#define IPROC_ANALOG_CONTROL           0x1c
+#define IPROC_CONTROLLER_STATUS                0x14
+#define IPROC_AUX_DATA                 0x20
+#define IPROC_SOFT_BYPASS_CONTROL      0x38
+#define IPROC_SOFT_BYPASS_DATA         0x3C
+
+/* IPROC ADC Channel register offsets */
+#define IPROC_ADC_CHANNEL_REGCTL1              0x800
+#define IPROC_ADC_CHANNEL_REGCTL2              0x804
+#define IPROC_ADC_CHANNEL_STATUS               0x808
+#define IPROC_ADC_CHANNEL_INTERRUPT_STATUS     0x80c
+#define IPROC_ADC_CHANNEL_INTERRUPT_MASK       0x810
+#define IPROC_ADC_CHANNEL_DATA                 0x814
+#define IPROC_ADC_CHANNEL_OFFSET               0x20
+
+/* Bit definitions for IPROC_REGCTL2 */
+#define IPROC_ADC_AUXIN_SCAN_ENA       BIT(0)
+#define IPROC_ADC_PWR_LDO              BIT(5)
+#define IPROC_ADC_PWR_ADC              BIT(4)
+#define IPROC_ADC_PWR_BG               BIT(3)
+#define IPROC_ADC_CONTROLLER_EN                BIT(17)
+
+/* Bit definitions for IPROC_INTERRUPT_MASK and IPROC_INTERRUPT_STATUS */
+#define IPROC_ADC_AUXDATA_RDY_INTR     BIT(3)
+#define IPROC_ADC_INTR                 9
+#define IPROC_ADC_INTR_MASK            (0xFF << IPROC_ADC_INTR)
+
+/* Bit definitions for IPROC_ANALOG_CONTROL */
+#define IPROC_ADC_CHANNEL_SEL          11
+#define IPROC_ADC_CHANNEL_SEL_MASK     (0x7 << IPROC_ADC_CHANNEL_SEL)
+
+/* Bit definitions for IPROC_ADC_CHANNEL_REGCTL1 */
+#define IPROC_ADC_CHANNEL_ROUNDS       0x2
+#define IPROC_ADC_CHANNEL_ROUNDS_MASK  (0x3F << IPROC_ADC_CHANNEL_ROUNDS)
+#define IPROC_ADC_CHANNEL_MODE         0x1
+#define IPROC_ADC_CHANNEL_MODE_MASK    (0x1 << IPROC_ADC_CHANNEL_MODE)
+#define IPROC_ADC_CHANNEL_MODE_TDM     0x1
+#define IPROC_ADC_CHANNEL_MODE_SNAPSHOT 0x0
+#define IPROC_ADC_CHANNEL_ENABLE       0x0
+#define IPROC_ADC_CHANNEL_ENABLE_MASK  0x1
+
+/* Bit definitions for IPROC_ADC_CHANNEL_REGCTL2 */
+#define IPROC_ADC_CHANNEL_WATERMARK    0x0
+#define IPROC_ADC_CHANNEL_WATERMARK_MASK \
+               (0x3F << IPROC_ADC_CHANNEL_WATERMARK)
+
+#define IPROC_ADC_WATER_MARK_LEVEL     0x1
+
+/* Bit definitions for IPROC_ADC_CHANNEL_STATUS */
+#define IPROC_ADC_CHANNEL_DATA_LOST            0x0
+#define IPROC_ADC_CHANNEL_DATA_LOST_MASK       \
+               (0x0 << IPROC_ADC_CHANNEL_DATA_LOST)
+#define IPROC_ADC_CHANNEL_VALID_ENTERIES       0x1
+#define IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK  \
+               (0xFF << IPROC_ADC_CHANNEL_VALID_ENTERIES)
+#define IPROC_ADC_CHANNEL_TOTAL_ENTERIES       0x9
+#define IPROC_ADC_CHANNEL_TOTAL_ENTERIES_MASK  \
+               (0xFF << IPROC_ADC_CHANNEL_TOTAL_ENTERIES)
+
+/* Bit definitions for IPROC_ADC_CHANNEL_INTERRUPT_MASK */
+#define IPROC_ADC_CHANNEL_WTRMRK_INTR                  0x0
+#define IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK             \
+               (0x1 << IPROC_ADC_CHANNEL_WTRMRK_INTR)
+#define IPROC_ADC_CHANNEL_FULL_INTR                    0x1
+#define IPROC_ADC_CHANNEL_FULL_INTR_MASK               \
+               (0x1 << IPROC_ADC_IPROC_ADC_CHANNEL_FULL_INTR)
+#define IPROC_ADC_CHANNEL_EMPTY_INTR                   0x2
+#define IPROC_ADC_CHANNEL_EMPTY_INTR_MASK              \
+               (0x1 << IPROC_ADC_CHANNEL_EMPTY_INTR)
+
+#define IPROC_ADC_WATER_MARK_INTR_ENABLE               0x1
+
+/* Number of time to retry a set of the interrupt mask reg */
+#define IPROC_ADC_INTMASK_RETRY_ATTEMPTS               10
+
+#define IPROC_ADC_READ_TIMEOUT        (HZ*2)
+
+#define iproc_adc_dbg_reg(dev, priv, reg) \
+do { \
+       u32 val; \
+       regmap_read(priv->regmap, reg, &val); \
+       dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
+} while (0)
+
+struct iproc_adc_priv {
+       struct regmap *regmap;
+       struct clk *adc_clk;
+       struct mutex mutex;
+       int  irqno;
+       int chan_val;
+       int chan_id;
+       struct completion completion;
+};
+
+static void iproc_adc_reg_dump(struct iio_dev *indio_dev)
+{
+       struct iproc_adc_priv *adc_priv;
+       struct device *dev = &indio_dev->dev;
+
+       adc_priv = iio_priv(indio_dev);
+
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL1);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_REGCTL2);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_THRES);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_MASK);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_INTERRUPT_STATUS);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_CONTROLLER_STATUS);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_ANALOG_CONTROL);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_AUX_DATA);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_CONTROL);
+       iproc_adc_dbg_reg(dev, adc_priv, IPROC_SOFT_BYPASS_DATA);
+}
+
+static irqreturn_t iproc_adc_interrupt_handler(int irq, void *data)
+{
+       u32 channel_intr_status;
+       u32 intr_status;
+       u32 intr_mask;
+       struct iio_dev *indio_dev = data;
+       struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
+
+       /*
+        * This interrupt is shared with the touchscreen driver.
+        * Make sure this interrupt is intended for us.
+        * Handle only ADC channel specific interrupts.
+        */
+       regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
+       regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &intr_mask);
+       intr_status = intr_status & intr_mask;
+       channel_intr_status = (intr_status & IPROC_ADC_INTR_MASK) >>
+                               IPROC_ADC_INTR;
+       if (channel_intr_status)
+               return IRQ_WAKE_THREAD;
+
+       return IRQ_NONE;
+}
+
+static irqreturn_t iproc_adc_interrupt_thread(int irq, void *data)
+{
+       irqreturn_t retval = IRQ_NONE;
+       struct iproc_adc_priv *adc_priv;
+       struct iio_dev *indio_dev = data;
+       unsigned int valid_entries;
+       u32 intr_status;
+       u32 intr_channels;
+       u32 channel_status;
+       u32 ch_intr_status;
+
+       adc_priv = iio_priv(indio_dev);
+
+       regmap_read(adc_priv->regmap, IPROC_INTERRUPT_STATUS, &intr_status);
+       dev_dbg(&indio_dev->dev, "iproc_adc_interrupt_thread(),INTRPT_STS:%x\n",
+                       intr_status);
+
+       intr_channels = (intr_status & IPROC_ADC_INTR_MASK) >> IPROC_ADC_INTR;
+       if (intr_channels) {
+               regmap_read(adc_priv->regmap,
+                           IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
+                           IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
+                           &ch_intr_status);
+
+               if (ch_intr_status & IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK) {
+                       regmap_read(adc_priv->regmap,
+                                       IPROC_ADC_CHANNEL_STATUS +
+                                       IPROC_ADC_CHANNEL_OFFSET *
+                                       adc_priv->chan_id,
+                                       &channel_status);
+
+                       valid_entries = ((channel_status &
+                               IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK) >>
+                               IPROC_ADC_CHANNEL_VALID_ENTERIES);
+                       if (valid_entries >= 1) {
+                               regmap_read(adc_priv->regmap,
+                                       IPROC_ADC_CHANNEL_DATA +
+                                       IPROC_ADC_CHANNEL_OFFSET *
+                                       adc_priv->chan_id,
+                                       &adc_priv->chan_val);
+                               complete(&adc_priv->completion);
+                       } else {
+                               dev_err(&indio_dev->dev,
+                                       "No data rcvd on channel %d\n",
+                                       adc_priv->chan_id);
+                       }
+                       regmap_write(adc_priv->regmap,
+                                       IPROC_ADC_CHANNEL_INTERRUPT_MASK +
+                                       IPROC_ADC_CHANNEL_OFFSET *
+                                       adc_priv->chan_id,
+                                       (ch_intr_status &
+                                       ~(IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK)));
+               }
+               regmap_write(adc_priv->regmap,
+                               IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
+                               IPROC_ADC_CHANNEL_OFFSET * adc_priv->chan_id,
+                               ch_intr_status);
+               regmap_write(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
+                               intr_channels);
+               retval = IRQ_HANDLED;
+       }
+
+       return retval;
+}
+
+static int iproc_adc_do_read(struct iio_dev *indio_dev,
+                          int channel,
+                          u16 *p_adc_data)
+{
+       int read_len = 0;
+       u32 val;
+       u32 mask;
+       u32 val_check;
+       int failed_cnt = 0;
+       struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
+
+       mutex_lock(&adc_priv->mutex);
+
+       /*
+        * After a read is complete the ADC interrupts will be disabled so
+        * we can assume this section of code is safe from interrupts.
+        */
+       adc_priv->chan_val = -1;
+       adc_priv->chan_id = channel;
+
+       reinit_completion(&adc_priv->completion);
+       /* Clear any pending interrupt */
+       regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
+                       IPROC_ADC_INTR_MASK | IPROC_ADC_AUXDATA_RDY_INTR,
+                       ((0x0 << channel) << IPROC_ADC_INTR) |
+                       IPROC_ADC_AUXDATA_RDY_INTR);
+
+       /* Configure channel for snapshot mode and enable  */
+       val = (BIT(IPROC_ADC_CHANNEL_ROUNDS) |
+               (IPROC_ADC_CHANNEL_MODE_SNAPSHOT << IPROC_ADC_CHANNEL_MODE) |
+               (0x1 << IPROC_ADC_CHANNEL_ENABLE));
+
+       mask = IPROC_ADC_CHANNEL_ROUNDS_MASK | IPROC_ADC_CHANNEL_MODE_MASK |
+               IPROC_ADC_CHANNEL_ENABLE_MASK;
+       regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL1 +
+                               IPROC_ADC_CHANNEL_OFFSET * channel),
+                               mask, val);
+
+       /* Set the Watermark for a channel */
+       regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_REGCTL2 +
+                                       IPROC_ADC_CHANNEL_OFFSET * channel),
+                                       IPROC_ADC_CHANNEL_WATERMARK_MASK,
+                                       0x1);
+
+       /* Enable water mark interrupt */
+       regmap_update_bits(adc_priv->regmap, (IPROC_ADC_CHANNEL_INTERRUPT_MASK +
+                                       IPROC_ADC_CHANNEL_OFFSET *
+                                       channel),
+                                       IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK,
+                                       IPROC_ADC_WATER_MARK_INTR_ENABLE);
+       regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val);
+
+       /* Enable ADC interrupt for a channel */
+       val |= (BIT(channel) << IPROC_ADC_INTR);
+       regmap_write(adc_priv->regmap, IPROC_INTERRUPT_MASK, val);
+
+       /*
+        * There seems to be a very rare issue where writing to this register
+        * does not take effect.  To work around the issue we will try multiple
+        * writes.  In total we will spend about 10*10 = 100 us attempting this.
+        * Testing has shown that this may loop a few time, but we have never
+        * hit the full count.
+        */
+       regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
+       while (val_check != val) {
+               failed_cnt++;
+
+               if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS)
+                       break;
+
+               udelay(10);
+               regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
+                               IPROC_ADC_INTR_MASK,
+                               ((0x1 << channel) <<
+                               IPROC_ADC_INTR));
+
+               regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
+       }
+
+       if (failed_cnt) {
+               dev_dbg(&indio_dev->dev,
+                       "IntMask failed (%d times)", failed_cnt);
+               if (failed_cnt > IPROC_ADC_INTMASK_RETRY_ATTEMPTS) {
+                       dev_err(&indio_dev->dev,
+                               "IntMask set failed. Read will likely fail.");
+                       read_len = -EIO;
+                       goto adc_err;
+               };
+       }
+       regmap_read(adc_priv->regmap, IPROC_INTERRUPT_MASK, &val_check);
+
+       if (wait_for_completion_timeout(&adc_priv->completion,
+               IPROC_ADC_READ_TIMEOUT) > 0) {
+
+               /* Only the lower 16 bits are relevant */
+               *p_adc_data = adc_priv->chan_val & 0xFFFF;
+               read_len = sizeof(*p_adc_data);
+
+       } else {
+               /*
+                * We never got the interrupt, something went wrong.
+                * Perhaps the interrupt may still be coming, we do not want
+                * that now.  Lets disable the ADC interrupt, and clear the
+                * status to put it back in to normal state.
+                */
+               read_len = -ETIMEDOUT;
+               goto adc_err;
+       }
+       mutex_unlock(&adc_priv->mutex);
+
+       return read_len;
+
+adc_err:
+       regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_MASK,
+                          IPROC_ADC_INTR_MASK,
+                          ((0x0 << channel) << IPROC_ADC_INTR));
+
+       regmap_update_bits(adc_priv->regmap, IPROC_INTERRUPT_STATUS,
+                          IPROC_ADC_INTR_MASK,
+                          ((0x0 << channel) << IPROC_ADC_INTR));
+
+       dev_err(&indio_dev->dev, "Timed out waiting for ADC data!\n");
+       iproc_adc_reg_dump(indio_dev);
+       mutex_unlock(&adc_priv->mutex);
+
+       return read_len;
+}
+
+static int iproc_adc_enable(struct iio_dev *indio_dev)
+{
+       u32 val;
+       u32 channel_id;
+       struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
+       int ret;
+
+       /* Set i_amux = 3b'000, select channel 0 */
+       ret = regmap_update_bits(adc_priv->regmap, IPROC_ANALOG_CONTROL,
+                               IPROC_ADC_CHANNEL_SEL_MASK, 0);
+       if (ret) {
+               dev_err(&indio_dev->dev,
+                       "failed to write IPROC_ANALOG_CONTROL %d\n", ret);
+               return ret;
+       }
+       adc_priv->chan_val = -1;
+
+       /*
+        * PWR up LDO, ADC, and Band Gap (0 to enable)
+        * Also enable ADC controller (set high)
+        */
+       ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
+       if (ret) {
+               dev_err(&indio_dev->dev,
+                       "failed to read IPROC_REGCTL2 %d\n", ret);
+               return ret;
+       }
+
+       val &= ~(IPROC_ADC_PWR_LDO | IPROC_ADC_PWR_ADC | IPROC_ADC_PWR_BG);
+
+       ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
+       if (ret) {
+               dev_err(&indio_dev->dev,
+                       "failed to write IPROC_REGCTL2 %d\n", ret);
+               return ret;
+       }
+
+       ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
+       if (ret) {
+               dev_err(&indio_dev->dev,
+                       "failed to read IPROC_REGCTL2 %d\n", ret);
+               return ret;
+       }
+
+       val |= IPROC_ADC_CONTROLLER_EN;
+       ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
+       if (ret) {
+               dev_err(&indio_dev->dev,
+                       "failed to write IPROC_REGCTL2 %d\n", ret);
+               return ret;
+       }
+
+       for (channel_id = 0; channel_id < indio_dev->num_channels;
+               channel_id++) {
+               ret = regmap_write(adc_priv->regmap,
+                               IPROC_ADC_CHANNEL_INTERRUPT_MASK +
+                               IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
+               if (ret) {
+                       dev_err(&indio_dev->dev,
+                           "failed to write ADC_CHANNEL_INTERRUPT_MASK %d\n",
+                           ret);
+                       return ret;
+               }
+
+               ret = regmap_write(adc_priv->regmap,
+                               IPROC_ADC_CHANNEL_INTERRUPT_STATUS +
+                               IPROC_ADC_CHANNEL_OFFSET * channel_id, 0);
+               if (ret) {
+                       dev_err(&indio_dev->dev,
+                           "failed to write ADC_CHANNEL_INTERRUPT_STATUS %d\n",
+                           ret);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
+static void iproc_adc_disable(struct iio_dev *indio_dev)
+{
+       u32 val;
+       int ret;
+       struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
+
+       ret = regmap_read(adc_priv->regmap, IPROC_REGCTL2, &val);
+       if (ret) {
+               dev_err(&indio_dev->dev,
+                       "failed to read IPROC_REGCTL2 %d\n", ret);
+               return;
+       }
+
+       val &= ~IPROC_ADC_CONTROLLER_EN;
+       ret = regmap_write(adc_priv->regmap, IPROC_REGCTL2, val);
+       if (ret) {
+               dev_err(&indio_dev->dev,
+                       "failed to write IPROC_REGCTL2 %d\n", ret);
+               return;
+       }
+}
+
+static int iproc_adc_read_raw(struct iio_dev *indio_dev,
+                         struct iio_chan_spec const *chan,
+                         int *val,
+                         int *val2,
+                         long mask)
+{
+       u16 adc_data;
+       int err;
+
+       switch (mask) {
+       case IIO_CHAN_INFO_RAW:
+               err =  iproc_adc_do_read(indio_dev, chan->channel, &adc_data);
+               if (err < 0)
+                       return err;
+               *val = adc_data;
+               return IIO_VAL_INT;
+       case IIO_CHAN_INFO_SCALE:
+               switch (chan->type) {
+               case IIO_VOLTAGE:
+                       *val = 1800;
+                       *val2 = 10;
+                       return IIO_VAL_FRACTIONAL_LOG2;
+               default:
+                       return -EINVAL;
+               }
+       default:
+               return -EINVAL;
+       }
+}
+
+static const struct iio_info iproc_adc_iio_info = {
+       .read_raw = &iproc_adc_read_raw,
+       .driver_module = THIS_MODULE,
+};
+
+#define IPROC_ADC_CHANNEL(_index, _id) {                \
+       .type = IIO_VOLTAGE,                            \
+       .indexed = 1,                                   \
+       .channel = _index,                              \
+       .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),   \
+       .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+       .datasheet_name = _id,                          \
+}
+
+static const struct iio_chan_spec iproc_adc_iio_channels[] = {
+       IPROC_ADC_CHANNEL(0, "adc0"),
+       IPROC_ADC_CHANNEL(1, "adc1"),
+       IPROC_ADC_CHANNEL(2, "adc2"),
+       IPROC_ADC_CHANNEL(3, "adc3"),
+       IPROC_ADC_CHANNEL(4, "adc4"),
+       IPROC_ADC_CHANNEL(5, "adc5"),
+       IPROC_ADC_CHANNEL(6, "adc6"),
+       IPROC_ADC_CHANNEL(7, "adc7"),
+};
+
+static int iproc_adc_probe(struct platform_device *pdev)
+{
+       struct iproc_adc_priv *adc_priv;
+       struct iio_dev *indio_dev = NULL;
+       int ret;
+
+       indio_dev = devm_iio_device_alloc(&pdev->dev,
+                                       sizeof(*adc_priv));
+       if (!indio_dev) {
+               dev_err(&pdev->dev, "failed to allocate iio device\n");
+               return -ENOMEM;
+       }
+
+       adc_priv = iio_priv(indio_dev);
+       platform_set_drvdata(pdev, indio_dev);
+
+       mutex_init(&adc_priv->mutex);
+
+       init_completion(&adc_priv->completion);
+
+       adc_priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+                          "adc-syscon");
+       if (IS_ERR(adc_priv->regmap)) {
+               dev_err(&pdev->dev, "failed to get handle for tsc syscon\n");
+               ret = PTR_ERR(adc_priv->regmap);
+               return ret;
+       }
+
+       adc_priv->adc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
+       if (IS_ERR(adc_priv->adc_clk)) {
+               dev_err(&pdev->dev,
+                       "failed getting clock tsc_clk\n");
+               ret = PTR_ERR(adc_priv->adc_clk);
+               return ret;
+       }
+
+       adc_priv->irqno = platform_get_irq(pdev, 0);
+       if (adc_priv->irqno <= 0) {
+               dev_err(&pdev->dev, "platform_get_irq failed\n");
+               ret = -ENODEV;
+               return ret;
+       }
+
+       ret = regmap_update_bits(adc_priv->regmap, IPROC_REGCTL2,
+                               IPROC_ADC_AUXIN_SCAN_ENA, 0);
+       if (ret) {
+               dev_err(&pdev->dev, "failed to write IPROC_REGCTL2 %d\n", ret);
+               return ret;
+       }
+
+       ret = devm_request_threaded_irq(&pdev->dev, adc_priv->irqno,
+                               iproc_adc_interrupt_thread,
+                               iproc_adc_interrupt_handler,
+                               IRQF_SHARED, "iproc-adc", indio_dev);
+       if (ret) {
+               dev_err(&pdev->dev, "request_irq error %d\n", ret);
+               return ret;
+       }
+
+       ret = clk_prepare_enable(adc_priv->adc_clk);
+       if (ret) {
+               dev_err(&pdev->dev,
+                       "clk_prepare_enable failed %d\n", ret);
+               return ret;
+       }
+
+       ret = iproc_adc_enable(indio_dev);
+       if (ret) {
+               dev_err(&pdev->dev, "failed to enable adc %d\n", ret);
+               goto err_adc_enable;
+       }
+
+       indio_dev->name = dev_name(&pdev->dev);
+       indio_dev->dev.parent = &pdev->dev;
+       indio_dev->dev.of_node = pdev->dev.of_node;
+       indio_dev->info = &iproc_adc_iio_info;
+       indio_dev->modes = INDIO_DIRECT_MODE;
+       indio_dev->channels = iproc_adc_iio_channels;
+       indio_dev->num_channels = ARRAY_SIZE(iproc_adc_iio_channels);
+
+       ret = iio_device_register(indio_dev);
+       if (ret) {
+               dev_err(&pdev->dev, "iio_device_register failed:err %d\n", ret);
+               goto err_clk;
+       }
+
+       return 0;
+
+err_clk:
+       iproc_adc_disable(indio_dev);
+err_adc_enable:
+       clk_disable_unprepare(adc_priv->adc_clk);
+
+       return ret;
+}
+
+static int iproc_adc_remove(struct platform_device *pdev)
+{
+       struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+       struct iproc_adc_priv *adc_priv = iio_priv(indio_dev);
+
+       iio_device_unregister(indio_dev);
+       iproc_adc_disable(indio_dev);
+       clk_disable_unprepare(adc_priv->adc_clk);
+
+       return 0;
+}
+
+static const struct of_device_id iproc_adc_of_match[] = {
+       {.compatible = "brcm,iproc-static-adc", },
+       { },
+};
+MODULE_DEVICE_TABLE(of, iproc_adc_of_match);
+
+static struct platform_driver iproc_adc_driver = {
+       .probe  = iproc_adc_probe,
+       .remove = iproc_adc_remove,
+       .driver = {
+               .name   = "iproc-static-adc",
+               .of_match_table = of_match_ptr(iproc_adc_of_match),
+       },
+};
+
+
+module_platform_driver(iproc_adc_driver);
+
+MODULE_DESCRIPTION("IPROC ADC driver");
+MODULE_AUTHOR("Broadcom");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

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