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Subject[PATCH 2/3] iio: adc: add new lp8788 adc driver
Date
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@ti.com>
---
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@ti.com>
+ *
+ * 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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