[PATCH V4 3/3] mfd: da9063: MFD support for OnKey driver

From: S Twiss
Date: Tue May 12 2015 - 09:39:07 EST


From: Steve Twiss <stwiss.opensource@xxxxxxxxxxx>

Add MFD support for the DA9063 OnKey driver

The function da9063_clear_fault_log() is added to mitigate the case of a
hardware power-cut after a long-long OnKey press. Although there is no
software intervention in this case (by definition) such a shutdown would
cause persistent information within the DA9063 FAULT_LOG that would be
available during the next device restart.

Clearance of this persistent register must be completed after such a
hardware power-cut operation has happened so that the FAULT_LOG does not
continue with previous values. The clearance function has been added here
in the kernel driver because wiping the fault-log cannot be counted on
outside the Linux kernel.


Signed-off-by: Steve Twiss <stwiss.opensource@xxxxxxxxxxx>

---
Version History

Changes in V4
- Additional description of MFD patch changes for FAULT_LOG in relation to
the requirements of the OnKey driver. Please see a further explanation of
the OnKey's operation in this thread: https://lkml.org/lkml/2015/4/29/406

Changes in V3
- The MFD code was originally in [PATCH V2 1/2]. This is now been moved into
this patch [PATCH V3 3/3].
- Whitespace cleanup

This patch applies against linux-next and v4.1-rc3


drivers/mfd/da9063-core.c | 54 ++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/da9063/pdata.h | 1 +
2 files changed, 55 insertions(+)

diff --git a/drivers/mfd/da9063-core.c b/drivers/mfd/da9063-core.c
index facd361..af841c1 100644
--- a/drivers/mfd/da9063-core.c
+++ b/drivers/mfd/da9063-core.c
@@ -60,6 +60,7 @@ static struct resource da9063_rtc_resources[] = {

static struct resource da9063_onkey_resources[] = {
{
+ .name = "ONKEY",
.start = DA9063_IRQ_ONKEY,
.end = DA9063_IRQ_ONKEY,
.flags = IORESOURCE_IRQ,
@@ -97,6 +98,7 @@ static const struct mfd_cell da9063_devs[] = {
.name = DA9063_DRVNAME_ONKEY,
.num_resources = ARRAY_SIZE(da9063_onkey_resources),
.resources = da9063_onkey_resources,
+ .of_compatible = "dlg,da9063-onkey",
},
{
.name = DA9063_DRVNAME_RTC,
@@ -109,12 +111,64 @@ static const struct mfd_cell da9063_devs[] = {
},
};

+static int da9063_clear_fault_log(struct da9063 *da9063)
+{
+ int ret = 0;
+ int fault_log = 0;
+
+ ret = regmap_read(da9063->regmap, DA9063_REG_FAULT_LOG, &fault_log);
+ if (ret < 0) {
+ dev_err(da9063->dev, "Cannot read FAULT_LOG.\n");
+ return -EIO;
+ }
+
+ if (fault_log) {
+ if (fault_log & DA9063_TWD_ERROR)
+ dev_dbg(da9063->dev,
+ "Fault log entry detected: DA9063_TWD_ERROR\n");
+ if (fault_log & DA9063_POR)
+ dev_dbg(da9063->dev,
+ "Fault log entry detected: DA9063_POR\n");
+ if (fault_log & DA9063_VDD_FAULT)
+ dev_dbg(da9063->dev,
+ "Fault log entry detected: DA9063_VDD_FAULT\n");
+ if (fault_log & DA9063_VDD_START)
+ dev_dbg(da9063->dev,
+ "Fault log entry detected: DA9063_VDD_START\n");
+ if (fault_log & DA9063_TEMP_CRIT)
+ dev_dbg(da9063->dev,
+ "Fault log entry detected: DA9063_TEMP_CRIT\n");
+ if (fault_log & DA9063_KEY_RESET)
+ dev_dbg(da9063->dev,
+ "Fault log entry detected: DA9063_KEY_RESET\n");
+ if (fault_log & DA9063_NSHUTDOWN)
+ dev_dbg(da9063->dev,
+ "Fault log entry detected: DA9063_NSHUTDOWN\n");
+ if (fault_log & DA9063_WAIT_SHUT)
+ dev_dbg(da9063->dev,
+ "Fault log entry detected: DA9063_WAIT_SHUT\n");
+ }
+
+ ret = regmap_write(da9063->regmap,
+ DA9063_REG_FAULT_LOG,
+ fault_log);
+ if (ret < 0)
+ dev_err(da9063->dev,
+ "Cannot reset FAULT_LOG values %d\n", ret);
+
+ return ret;
+}
+
int da9063_device_init(struct da9063 *da9063, unsigned int irq)
{
struct da9063_pdata *pdata = da9063->dev->platform_data;
int model, variant_id, variant_code;
int ret;

+ ret = da9063_clear_fault_log(da9063);
+ if (ret < 0)
+ dev_err(da9063->dev, "Cannot clear fault log\n");
+
if (pdata) {
da9063->flags = pdata->flags;
da9063->irq_base = pdata->irq_base;
diff --git a/include/linux/mfd/da9063/pdata.h b/include/linux/mfd/da9063/pdata.h
index 95c8742..612383b 100644
--- a/include/linux/mfd/da9063/pdata.h
+++ b/include/linux/mfd/da9063/pdata.h
@@ -103,6 +103,7 @@ struct da9063;
struct da9063_pdata {
int (*init)(struct da9063 *da9063);
int irq_base;
+ bool key_power;
unsigned flags;
struct da9063_regulators_pdata *regulators_pdata;
struct led_platform_data *leds_pdata;
--
end-of-patch for PATCH V4

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