@@ -28,6 +28,7 @@
#include <linux/mfd/abx500/ab8500-gpadc.h>
#include <linux/mfd/abx500/ux500_chargalg.h>
#include <linux/pm2301_charger.h>
+#include <linux/gpio.h>
#include "pm2301_charger.h"
@@ -110,9 +111,35 @@ static const struct i2c_device_id pm2xxx_ident[] = {
{ }
};
+static void set_lpn_pin(struct pm2xxx_charger *pm2)
+{
+ if (pm2->ac.charger_connected)
+ return;
+ gpio_set_value(pm2->lpn_pin, 1);
+
+ return;
+}
+
+static void clear_lpn_pin(struct pm2xxx_charger *pm2)
+{
+ if (pm2->ac.charger_connected)
+ return;
+ gpio_set_value(pm2->lpn_pin, 0);
+
+ return;
+}
+
int pm2xxx_reg_read(struct pm2xxx_charger *pm2, int reg, u8 *val)
{
int ret;
+ /*
+ * When AC adaptor is unplugged, the host
+ * must put LPN high to be able to
+ * communicate by I2C with PM2301
+ * and receive I2C "acknowledge" from PM2301.
+ */
+ mutex_lock(&pm2->lock);
+ set_lpn_pin(pm2);
ret = i2c_smbus_read_i2c_block_data(pm2->config.pm2xxx_i2c, reg,
1, val);
@@ -120,6 +147,8 @@ int pm2xxx_reg_read(struct pm2xxx_charger *pm2, int reg, u8 *val)
dev_err(pm2->dev, "Error reading register at 0x%x\n", reg);
else
ret = 0;
+ clear_lpn_pin(pm2);
+ mutex_unlock(&pm2->lock);
return ret;
}
@@ -127,6 +156,14 @@ int pm2xxx_reg_read(struct pm2xxx_charger *pm2, int reg, u8 *val)
int pm2xxx_reg_write(struct pm2xxx_charger *pm2, int reg, u8 val)
{
int ret;
+ /*
+ * When AC adaptor is unplugged, the host
+ * must put LPN high to be able to
+ * communicate by I2C with PM2301
+ * and receive I2C "acknowledge" from PM2301.
+ */
+ mutex_lock(&pm2->lock);
+ set_lpn_pin(pm2);
ret = i2c_smbus_write_i2c_block_data(pm2->config.pm2xxx_i2c, reg,
1, &val);
@@ -134,6 +171,8 @@ int pm2xxx_reg_write(struct pm2xxx_charger *pm2, int reg, u8 val)
dev_err(pm2->dev, "Error writing register at 0x%x\n", reg);
else
ret = 0;
+ clear_lpn_pin(pm2);
+ mutex_unlock(&pm2->lock);
return ret;
}
@@ -850,6 +889,14 @@ static int __devinit pm2xxx_wall_charger_probe(struct i2c_client *i2c_client,
pm2->bat = pl_data->battery;
+ /*get lpn GPIO from platform data*/
+ if (!pm2->pdata->lpn_gpio) {
+ dev_err(pm2->dev, "no lpn gpio data supplied\n");
+ ret = -EINVAL;
+ goto free_device_info;
+ }
+ pm2->lpn_pin = pm2->pdata->lpn_gpio;
+
if (!i2c_check_functionality(i2c_client->adapter,
I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_READ_WORD_DATA)) {
@@ -929,10 +976,25 @@ static int __devinit pm2xxx_wall_charger_probe(struct i2c_client *i2c_client,
goto unregister_pm2xxx_charger;
}
+ /*Initialize lock*/
+ mutex_init(&pm2->lock);
+
/*
- * I2C Read/Write will fail, if AC adaptor is not connected.
- * fix the charger detection mechanism.
+ * Charger detection mechanism requires pulling up the LPN pin
+ * while i2c communication if Charger is not connected
+ * LPN pin of PM2301 is GPIO60 of AB9540
*/
+ ret = gpio_request(pm2->lpn_pin, "pm2301_lpm_gpio");
+ if (ret < 0) {
+ dev_err(pm2->dev, "pm2301_lpm_gpio request failed\n");
+ goto unregister_pm2xxx_charger;
+ }
+ ret = gpio_direction_output(pm2->lpn_pin, 0);
+ if (ret < 0) {
+ dev_err(pm2->dev, "pm2301_lpm_gpio direction failed\n");
+ goto free_gpio;
+ }
+
ret = pm2xxx_charger_detection(pm2, &val);
if ((ret == 0) && val) {
@@ -951,7 +1013,8 @@ static int __devinit pm2xxx_wall_charger_probe(struct i2c_client *i2c_client,
err_deep_debug:
/* disable interrupt */
free_irq(pm2->pdata->irq_number, pm2);
-
+free_gpio:
+ gpio_free(pm2->lpn_pin);
unregister_pm2xxx_charger:
/* unregister power supply */
power_supply_unregister(&pm2->ac_chg.psy);
@@ -987,6 +1050,9 @@ static int __devexit pm2xxx_wall_charger_remove(struct i2c_client *i2c_client)
power_supply_unregister(&pm2->ac_chg.psy);
+ /*Free GPIO60*/
+ gpio_free(pm2->lpn_pin);
+
kfree(pm2);
return 0;
@@ -493,6 +493,7 @@ struct pm2xxx_charger {
int old_vbat;
int failure_case;
int failure_input_ovv;
+ unsigned int lpn_pin;
struct pm2xxx_interrupts *pm2_int;
struct ab8500_gpadc *gpadc;
struct regulator *regu;
@@ -49,6 +49,7 @@ struct pm2xxx_charger_platform_data {
int i2c_bus;
const char *label;
int irq_number;
+ unsigned int lpn_gpio;
int irq_type;
};