[PATCH v3 3/5] max17042: Add support for signalling change in SOC

From: dirk . brandewie
Date: Mon Dec 12 2011 - 13:42:12 EST


From: Dirk Brandewie <dirk.brandewie@xxxxxxxxx>

If platform has the alert pin attached to an interrupt source have the
driver signal a change in the SOC every 1 percent.

Signed-off-by: Dirk Brandewie <dirk.brandewie@xxxxxxxxx>
---
drivers/power/max17042_battery.c | 54 ++++++++++++++++++++++++++++++++++++++
1 files changed, 54 insertions(+), 0 deletions(-)

diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index f2ca950..ac17d36 100644
--- a/drivers/power/max17042_battery.c
+++ b/drivers/power/max17042_battery.c
@@ -27,6 +27,7 @@
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/delay.h>
+#include <linux/interrupt.h>
#include <linux/mod_devicetable.h>
#include <linux/power_supply.h>
#include <linux/power/max17042_battery.h>
@@ -43,6 +44,11 @@
#define STATUS_SMX_BIT (1 << 14)
#define STATUS_BR_BIT (1 << 15)

+/* Interrupt mask bits */
+#define CONFIG_ALRT_BIT_ENBL (1 << 2)
+#define STATUS_INTR_SOC_BIT (1 << 14)
+#define STATUS_INTR_LOW_SOC_BIT (1 << 10)
+
#define VFSOC0_LOCK 0x0000
#define VFSOC0_UNLOCK 0x0080
#define MODEL_UNLOCK1 0X0059
@@ -522,6 +528,40 @@ static int max17042_init_chip(struct max17042_chip *chip)
return 0;
}

+static void max17042_set_soc_threshold(struct max17042_chip *chip, u16 off)
+{
+ u16 soc, soc_tr;
+
+ /* program interrupt thesholds such that we should
+ * get interrupt for every 'off' perc change in the soc
+ */
+ soc = max17042_read_reg(chip->client, MAX17042_RepSOC) >> 8;
+ soc_tr = (soc + off) << 8;
+ soc_tr |= (soc - off);
+ max17042_write_reg(chip->client, MAX17042_SALRT_Th, soc_tr);
+}
+
+static irqreturn_t max17042_intr_handler(int id, void *dev)
+{
+ return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t max17042_thread_handler(int id, void *dev)
+{
+ struct max17042_chip *chip = dev;
+ u16 val;
+
+ val = max17042_read_reg(chip->client, MAX17042_STATUS);
+ if ((val & STATUS_INTR_SOC_BIT) ||
+ (val & STATUS_INTR_LOW_SOC_BIT)) {
+ printk(KERN_ERR "SOC threshold INTR\n");
+ dev_info(&chip->client->dev, "SOC threshold INTR\n");
+ max17042_set_soc_threshold(chip, 1);
+ }
+
+ power_supply_changed(&chip->battery);
+ return IRQ_HANDLED;
+}

static void max17042_init_worker(struct work_struct *work)
{
@@ -584,6 +624,20 @@ static int __devinit max17042_probe(struct i2c_client *client,
MAX17042_DEFAULT_SNS_RESISTOR;
}

+ if (client->irq) {
+ ret = request_threaded_irq(client->irq, max17042_intr_handler,
+ max17042_thread_handler,
+ 0, chip->battery.name, chip);
+ if (!ret) {
+ reg = max17042_read_reg(client, MAX17042_CONFIG);
+ reg |= CONFIG_ALRT_BIT_ENBL;
+ max17042_write_reg(client, MAX17042_CONFIG, reg);
+ max17042_set_soc_threshold(chip, 1);
+ } else
+ dev_err(&client->dev, "%s(): cannot get IRQ\n",
+ __func__);
+ }
+
reg = max17042_read_reg(chip->client, MAX17042_STATUS);

if (reg & STATUS_POR_BIT) {
--
1.7.7.3

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