TI LP8788 has ADC function.
The result of LP878 ADC is used in the LP8788 power supply driver.
(such like getting the battery voltage, temperature and etc)
Signed-off-by: Milo(Woogyom) Kim <milo.kim@xxxxxx>
---
drivers/iio/adc/Kconfig | 6 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/lp8788_adc.c | 240 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 247 insertions(+), 0 deletions(-)
create mode 100644 drivers/iio/adc/lp8788_adc.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 8a78b4f..30c06ed 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -22,4 +22,10 @@ config AT91_ADC
help
Say yes here to build support for Atmel AT91 ADC.
+config LP8788_ADC
+ bool "LP8788 ADC driver"
+ depends on MFD_LP8788
+ help
+ Say yes here to build support for TI LP8788 ADC.
+
endmenu
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 52eec25..72f9a76 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -4,3 +4,4 @@
obj-$(CONFIG_AD7266) += ad7266.o
obj-$(CONFIG_AT91_ADC) += at91_adc.o
+obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
diff --git a/drivers/iio/adc/lp8788_adc.c b/drivers/iio/adc/lp8788_adc.c
new file mode 100644
index 0000000..30767d5
--- /dev/null
+++ b/drivers/iio/adc/lp8788_adc.c
@@ -0,0 +1,240 @@
+/*
+ * TI LP8788 MFD - ADC driver
+ *
+ * Copyright 2012 Texas Instruments
+ *
+ * Author: Milo(Woogyom) Kim <milo.kim@xxxxxx>
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/driver.h>
+#include <linux/mfd/lp8788.h>
+
+/* register address */
+#define LP8788_ADC_CONF 0x60
+#define LP8788_ADC_RAW 0x61
+#define LP8788_ADC_DONE 0x63
+
+#define START_ADC_CHANNEL LPADC_VBATT_5P5
+#define END_ADC_CHANNEL LPADC_MAX
+#define ADC_CONV_START 1
+#define ADC_CONV_DELAY_US 100
+
+struct lp8788_adc {
+ struct lp8788 *lp;
+ struct iio_dev *indio_dev;
+};
+
+static const int adc_const[LPADC_MAX] = {
+ [LPADC_VBATT_5P5] = 1343,
+ [LPADC_VIN_CHG] = 3052,
+ [LPADC_IBATT] = 610,
+ [LPADC_IC_TEMP] = 610,
+ [LPADC_VBATT_6P0] = 1465,
+ [LPADC_VBATT_5P0] = 1221,
+ [LPADC_ADC1] = 610,
+ [LPADC_ADC2] = 610,
+ [LPADC_VDD] = 1025,
+ [LPADC_VCOIN] = 757,
+ [LPADC_VDD_LDO] = 610,
+ [LPADC_ADC3] = 610,
+ [LPADC_ADC4] = 610,
+};
+
+static inline unsigned int _get_adc_micro_unit(enum lp8788_adc_id id,
+ unsigned int adc_result)
+{
+ return adc_const[id] * ((adc_result * 1000 + 500) / 1000);
+}
+
+static int lp8788_adc_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct lp8788_adc *adc = iio_priv(indio_dev);
+ int retry = 5;
+ unsigned int msb, lsb;
+ u8 data, rawdata[2], shift;
+ int size = ARRAY_SIZE(rawdata);
+
+ if (mask != IIO_CHAN_INFO_RAW)
+ return -EINVAL;
+
+ data = (chan->channel << 1) | ADC_CONV_START;
+ if (lp8788_write_byte(adc->lp, LP8788_ADC_CONF, data))
+ goto err;
+
+ /* retry until adc conversion is done */
+ data = 0;
+ while (retry--) {
+ udelay(ADC_CONV_DELAY_US);
+
+ if (lp8788_read_byte(adc->lp, LP8788_ADC_DONE, &data))
+ goto err;
+
+ /* conversion done */
+ if (data)
+ break;
+ }
+
+ if (lp8788_read_multi_bytes(adc->lp, LP8788_ADC_RAW, rawdata, size))
+ goto err;
+
+ shift = chan->scan_type.shift;
+ msb = (rawdata[0] << shift) & 0x00000ff0;
+ lsb = (rawdata[1] >> shift) & 0x0000000f;
+ *val = _get_adc_micro_unit(chan->channel, msb | lsb);
+
+ return IIO_VAL_INT;
+err:
+ return -EINVAL;
+}
+
+static const struct iio_info lp8788_adc_info = {
+ .read_raw = &lp8788_adc_read_raw,
+ .driver_module = THIS_MODULE,
+};
+
+#define LP8788_COMMON_CH(id) \
+ .indexed = 1, \
+ .output = 1, \
+ .channel = LPADC_##id, \
+ .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT, \
+ .address = LP8788_ADC_RAW, \
+ .scan_type = IIO_ST('u', 8, 12, 4), \
+ .scan_index = 1, \
+ .datasheet_name = #id, \
+
+#define LP8788_V_CHAN(id) { \
+ .type = IIO_VOLTAGE, \
+ LP8788_COMMON_CH(id) \
+}
+
+#define LP8788_I_CHAN(id) { \
+ .type = IIO_CURRENT, \
+ LP8788_COMMON_CH(id) \
+}
+
+#define LP8788_T_CHAN(id) { \
+ .type = IIO_TEMP, \
+ LP8788_COMMON_CH(id) \
+}
+
+static struct iio_chan_spec lp8788_adc_channels[] = {
+ [LPADC_VBATT_5P5] = LP8788_V_CHAN(VBATT_5P5),
+ [LPADC_VIN_CHG] = LP8788_V_CHAN(VIN_CHG),
+ [LPADC_IBATT] = LP8788_I_CHAN(IBATT),
+ [LPADC_IC_TEMP] = LP8788_T_CHAN(IC_TEMP),
+ [LPADC_VBATT_6P0] = LP8788_V_CHAN(VBATT_6P0),
+ [LPADC_VBATT_5P0] = LP8788_V_CHAN(VBATT_5P0),
+ [LPADC_ADC1] = LP8788_V_CHAN(ADC1),
+ [LPADC_ADC2] = LP8788_V_CHAN(ADC2),
+ [LPADC_VDD] = LP8788_V_CHAN(VDD),
+ [LPADC_VCOIN] = LP8788_V_CHAN(VCOIN),
+ [LPADC_VDD_LDO] = LP8788_V_CHAN(VDD_LDO),
+ [LPADC_ADC3] = LP8788_V_CHAN(ADC3),
+ [LPADC_ADC4] = LP8788_V_CHAN(ADC4),
+};
+
+static int __devinit lp8788_adc_probe(struct platform_device *pdev)
+{
+ struct lp8788 *lp = dev_get_drvdata(pdev->dev.parent);
+ struct iio_map *map;
+ struct lp8788_adc *adc;
+ struct iio_dev *indio_dev;
+ int i, ret;
+
+ adc = devm_kzalloc(lp->dev, sizeof(struct lp8788_adc), GFP_KERNEL);
+ if (!adc)
+ return -ENOMEM;
+
+ indio_dev = iio_device_alloc(sizeof(struct iio_dev));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ adc = iio_priv(indio_dev);
+ adc->lp = lp;
+ adc->indio_dev = indio_dev;
+ platform_set_drvdata(pdev, adc);
+
+ if (lp->pdata) {
+ for (i = START_ADC_CHANNEL; i < END_ADC_CHANNEL ; i++) {
+ map = lp->pdata->adc_pdata[i];
+ ret = iio_map_array_register(indio_dev, map);
+ if (ret) {
+ dev_err(lp->dev, "iio map err: %d\n", ret);
+ goto err_iio_map_array;
+ }
+ }
+ }
+
+ indio_dev->dev.parent = lp->dev;
+ indio_dev->name = pdev->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &lp8788_adc_info;
+ indio_dev->channels = lp8788_adc_channels;
+ indio_dev->num_channels = ARRAY_SIZE(lp8788_adc_channels);
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err(lp->dev, "iio dev register err: %d\n", ret);
+ goto err_iio_register;
+ }
+
+ return 0;
+
+err_iio_map_array:
+ while (--i >= START_ADC_CHANNEL) {
+ map = lp->pdata->adc_pdata[i];
+ iio_map_array_unregister(indio_dev, map);
+ }
+err_iio_register:
+ iio_device_free(indio_dev);
+ return ret;
+}
+
+static int __devexit lp8788_adc_remove(struct platform_device *pdev)
+{
+ struct lp8788_adc *adc = platform_get_drvdata(pdev);
+ struct lp8788 *lp = adc->lp;
+ struct iio_dev *indio_dev = adc->indio_dev;
+ struct iio_map *map;
+ int i;
+
+ if (lp->pdata) {
+ for (i = START_ADC_CHANNEL; i < END_ADC_CHANNEL ; i++) {
+ map = lp->pdata->adc_pdata[i];
+ iio_map_array_unregister(indio_dev, map);
+ }
+ }
+
+ iio_device_unregister(indio_dev);
+ iio_device_free(indio_dev);
+
+ return 0;
+}
+
+static struct platform_driver lp8788_adc_driver = {
+ .probe = lp8788_adc_probe,
+ .remove = __devexit_p(lp8788_adc_remove),
+ .driver = {
+ .name = LP8788_DEV_ADC,
+ .owner = THIS_MODULE,
+ },
+};
+module_platform_driver(lp8788_adc_driver);
+
+MODULE_DESCRIPTION("Texas Instruments LP8788 ADC Driver");
+MODULE_AUTHOR("Milo Kim");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:lp8788-adc");
--
1.7.2.5
Best Regards,
Milo
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