mfd: Reentrance and revamp ab8500 gpadc fetching interface
This revamps the interface so that AB8500 GPADCs are fetched by
name. Probed GPADCs are added to a list and this list is searched
for a matching GPADC. This makes it possible to have multiple
AB8500 GPADC instances instead of it being a singleton, and
rids the need to keep a GPADC pointer around in the core AB8500
MFD struct.
Currently the match is made to the device name which is by default
numbered from the device instance such as "ab8500-gpadc.0" but
by using the .init_name field of the device a more intiutive
naming for the GPADC blocks can be achieved if desired.
Signed-off-by: Daniel Willerud <daniel.willerud@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/drivers/mfd/ab8500-gpadc.c b/drivers/mfd/ab8500-gpadc.c
index f60f71f4..178cbc5 100644
--- a/drivers/mfd/ab8500-gpadc.c
+++ b/drivers/mfd/ab8500-gpadc.c
@@ -3,6 +3,7 @@
*
* License Terms: GNU General Public License v2
* Author: Arun R Murthy <arun.murthy@stericsson.com>
+ * Author: Daniel Willerud <daniel.willerud@stericsson.com>
*/
#include <linux/init.h>
#include <linux/module.h>
@@ -15,6 +16,7 @@
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/slab.h>
+#include <linux/list.h>
#include <linux/mfd/ab8500.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/ab8500/ab8500-gpadc.h>
@@ -48,21 +50,41 @@
/**
* struct ab8500_gpadc - ab8500 GPADC device information
* @dev: pointer to the struct device
- * @parent: pointer to the parent device structure ab8500
+ * @node: a list of AB8500 GPADCs, hence prepared for
+ reentrance
* @ab8500_gpadc_complete: pointer to the struct completion, to indicate
* the completion of gpadc conversion
* @ab8500_gpadc_lock: structure of type mutex
* @regu: pointer to the struct regulator
* @irq: interrupt number that is used by gpadc
*/
-static struct ab8500_gpadc {
+struct ab8500_gpadc {
struct device *dev;
- struct ab8500 *parent;
+ struct list_head node;
struct completion ab8500_gpadc_complete;
struct mutex ab8500_gpadc_lock;
struct regulator *regu;
int irq;
-} *di;
+};
+
+static LIST_HEAD(ab8500_gpadc_list);
+
+/**
+ * ab8500_gpadc_get() - returns a reference to the primary AB8500 GPADC
+ * (i.e. the first GPADC in the instance list)
+ */
+struct ab8500_gpadc *ab8500_gpadc_get(char *name)
+{
+ struct ab8500_gpadc *gpadc;
+
+ list_for_each_entry(gpadc, &ab8500_gpadc_list, node) {
+ if (!strcmp(name, dev_name(gpadc->dev)))
+ return gpadc;
+ }
+
+ return ERR_PTR(-ENOENT);
+}
+EXPORT_SYMBOL(ab8500_gpadc_get);
/**
* ab8500_gpadc_convert() - gpadc conversion
@@ -72,24 +94,24 @@
* data. Thereafter calibration has to be made to obtain the
* data in the required quantity measurement.
*/
-int ab8500_gpadc_convert(u8 input)
+int ab8500_gpadc_convert(struct ab8500_gpadc *gpadc, u8 input)
{
int ret;
u16 data = 0;
int looplimit = 0;
u8 val, low_data, high_data;
- if (!di)
+ if (!gpadc)
return -ENODEV;
- mutex_lock(&di->ab8500_gpadc_lock);
+ mutex_lock(&gpadc->ab8500_gpadc_lock);
/* Enable VTVout LDO this is required for GPADC */
- regulator_enable(di->regu);
+ regulator_enable(gpadc->regu);
/* Check if ADC is not busy, lock and proceed */
do {
- ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
- AB8500_GPADC_STAT_REG, &val);
+ ret = abx500_get_register_interruptible(gpadc->dev,
+ AB8500_GPADC, AB8500_GPADC_STAT_REG, &val);
if (ret < 0)
goto out;
if (!(val & GPADC_BUSY))
@@ -97,75 +119,76 @@
msleep(10);
} while (++looplimit < 10);
if (looplimit >= 10 && (val & GPADC_BUSY)) {
- dev_err(di->dev, "gpadc_conversion: GPADC busy");
+ dev_err(gpadc->dev, "gpadc_conversion: GPADC busy");
ret = -EINVAL;
goto out;
}
/* Enable GPADC */
- ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
- AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
+ ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
+ AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_GPADC, EN_GPADC);
if (ret < 0) {
- dev_err(di->dev, "gpadc_conversion: enable gpadc failed\n");
+ dev_err(gpadc->dev, "gpadc_conversion: enable gpadc failed\n");
goto out;
}
/* Select the input source and set average samples to 16 */
- ret = abx500_set_register_interruptible(di->dev, AB8500_GPADC,
+ ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_CTRL2_REG, (input | SW_AVG_16));
if (ret < 0) {
- dev_err(di->dev,
+ dev_err(gpadc->dev,
"gpadc_conversion: set avg samples failed\n");
goto out;
}
/* Enable ADC, Buffering and select rising edge, start Conversion */
- ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
- AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
+ ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
+ AB8500_GPADC, AB8500_GPADC_CTRL1_REG, EN_BUF, EN_BUF);
if (ret < 0) {
- dev_err(di->dev,
+ dev_err(gpadc->dev,
"gpadc_conversion: select falling edge failed\n");
goto out;
}
- ret = abx500_mask_and_set_register_interruptible(di->dev, AB8500_GPADC,
- AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
+ ret = abx500_mask_and_set_register_interruptible(gpadc->dev,
+ AB8500_GPADC, AB8500_GPADC_CTRL1_REG, ADC_SW_CONV, ADC_SW_CONV);
if (ret < 0) {
- dev_err(di->dev,
+ dev_err(gpadc->dev,
"gpadc_conversion: start s/w conversion failed\n");
goto out;
}
/* wait for completion of conversion */
- if (!wait_for_completion_timeout(&di->ab8500_gpadc_complete, 2*HZ)) {
- dev_err(di->dev,
+ if (!wait_for_completion_timeout(&gpadc->ab8500_gpadc_complete, 2*HZ)) {
+ dev_err(gpadc->dev,
"timeout: didnt recieve GPADC conversion interrupt\n");
ret = -EINVAL;
goto out;
}
/* Read the converted RAW data */
- ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
+ ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_MANDATAL_REG, &low_data);
if (ret < 0) {
- dev_err(di->dev, "gpadc_conversion: read low data failed\n");
+ dev_err(gpadc->dev, "gpadc_conversion: read low data failed\n");
goto out;
}
- ret = abx500_get_register_interruptible(di->dev, AB8500_GPADC,
+ ret = abx500_get_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_MANDATAH_REG, &high_data);
if (ret < 0) {
- dev_err(di->dev, "gpadc_conversion: read high data failed\n");
+ dev_err(gpadc->dev,
+ "gpadc_conversion: read high data failed\n");
goto out;
}
data = (high_data << 8) | low_data;
/* Disable GPADC */
- ret = abx500_set_register_interruptible(di->dev, AB8500_GPADC,
+ ret = abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_CTRL1_REG, DIS_GPADC);
if (ret < 0) {
- dev_err(di->dev, "gpadc_conversion: disable gpadc failed\n");
+ dev_err(gpadc->dev, "gpadc_conversion: disable gpadc failed\n");
goto out;
}
/* Disable VTVout LDO this is required for GPADC */
- regulator_disable(di->regu);
- mutex_unlock(&di->ab8500_gpadc_lock);
+ regulator_disable(gpadc->regu);
+ mutex_unlock(&gpadc->ab8500_gpadc_lock);
return data;
out:
@@ -175,12 +198,12 @@
* GPADC status register to go low. In V1.1 there wait_for_completion
* seems to timeout when waiting for an interrupt.. Not seen in V2.0
*/
- (void) abx500_set_register_interruptible(di->dev, AB8500_GPADC,
+ (void) abx500_set_register_interruptible(gpadc->dev, AB8500_GPADC,
AB8500_GPADC_CTRL1_REG, DIS_GPADC);
- regulator_disable(di->regu);
- mutex_unlock(&di->ab8500_gpadc_lock);
- dev_err(di->dev, "gpadc_conversion: Failed to AD convert channel %d\n",
- input);
+ regulator_disable(gpadc->regu);
+ mutex_unlock(&gpadc->ab8500_gpadc_lock);
+ dev_err(gpadc->dev,
+ "gpadc_conversion: Failed to AD convert channel %d\n", input);
return ret;
}
EXPORT_SYMBOL(ab8500_gpadc_convert);
@@ -195,9 +218,9 @@
* can be read from the registers.
* Returns IRQ status(IRQ_HANDLED)
*/
-static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_di)
+static irqreturn_t ab8500_bm_gpswadcconvend_handler(int irq, void *_gpadc)
{
- struct ab8500_gpadc *gpadc = _di;
+ struct ab8500_gpadc *gpadc = _gpadc;
complete(&gpadc->ab8500_gpadc_complete);
@@ -215,16 +238,16 @@
return -ENOMEM;
}
- gpadc->parent = dev_get_drvdata(pdev->dev.parent);
gpadc->irq = platform_get_irq_byname(pdev, "SW_CONV_END");
if (gpadc->irq < 0) {
- dev_err(gpadc->dev, "failed to get platform irq-%d\n", di->irq);
+ dev_err(gpadc->dev, "failed to get platform irq-%d\n",
+ gpadc->irq);
ret = gpadc->irq;
goto fail;
}
gpadc->dev = &pdev->dev;
- mutex_init(&di->ab8500_gpadc_lock);
+ mutex_init(&gpadc->ab8500_gpadc_lock);
/* Initialize completion used to notify completion of conversion */
init_completion(&gpadc->ab8500_gpadc_complete);
@@ -246,7 +269,7 @@
dev_err(gpadc->dev, "failed to get vtvout LDO\n");
goto fail;
}
- di = gpadc;
+ list_add_tail(&gpadc->node, &ab8500_gpadc_list);
dev_dbg(gpadc->dev, "probe success\n");
return 0;
fail:
@@ -259,8 +282,10 @@
{
struct ab8500_gpadc *gpadc = platform_get_drvdata(pdev);
+ /* remove this gpadc entry from the list */
+ list_del(&gpadc->node);
/* remove interrupt - completion of Sw ADC conversion */
- free_irq(gpadc->irq, di);
+ free_irq(gpadc->irq, gpadc);
/* disable VTVout LDO that is being used by GPADC */
regulator_put(gpadc->regu);
kfree(gpadc);
@@ -291,6 +316,6 @@
module_exit(ab8500_gpadc_exit);
MODULE_LICENSE("GPL v2");
-MODULE_AUTHOR("Arun R Murthy");
+MODULE_AUTHOR("Arun R Murthy, Daniel Willerud");
MODULE_ALIAS("platform:ab8500_gpadc");
MODULE_DESCRIPTION("AB8500 GPADC driver");
