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authorSebastian Reichel <sebastian.reichel@collabora.com>2020-05-13 20:56:04 +0200
committerSebastian Reichel <sre@kernel.org>2020-05-29 00:39:16 +0200
commit79bcd5a4a66076a8a8dacd7f4a3be1952283aef4 (patch)
treee428a5180447805819165e87d40029c5c52ff7fa /drivers/power
parentc4b12a2f3f3de670f6be5e96092a2cab0b877f1a (diff)
power: supply: sbs-battery: add PEC support
SBS batteries optionally have support for PEC. This enables PEC handling based on the implemented SBS version as suggested by the standard. The support for PEC is re-evaluated when the battery is hotplugged into the system, since there might be systems supporting batteries from different SBS generations. Reviewed-by: Emil Velikov <emil.velikov@collabora.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Diffstat (limited to 'drivers/power')
-rw-r--r--drivers/power/supply/sbs-battery.c72
1 files changed, 69 insertions, 3 deletions
diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c
index a9a1d28dabbe..ab774d491269 100644
--- a/drivers/power/supply/sbs-battery.c
+++ b/drivers/power/supply/sbs-battery.c
@@ -46,6 +46,14 @@ enum {
REG_MODEL_NAME,
};
+#define REG_ADDR_SPEC_INFO 0x1A
+#define SPEC_INFO_VERSION_MASK GENMASK(7, 4)
+#define SPEC_INFO_VERSION_SHIFT 4
+
+#define SBS_VERSION_1_0 1
+#define SBS_VERSION_1_1 2
+#define SBS_VERSION_1_1_WITH_PEC 3
+
/* Battery Mode defines */
#define BATTERY_MODE_OFFSET 0x03
#define BATTERY_MODE_CAPACITY_MASK BIT(15)
@@ -175,6 +183,64 @@ static char model_name[I2C_SMBUS_BLOCK_MAX + 1];
static char manufacturer[I2C_SMBUS_BLOCK_MAX + 1];
static bool force_load;
+static int sbs_update_presence(struct sbs_info *chip, bool is_present)
+{
+ struct i2c_client *client = chip->client;
+ int retries = chip->i2c_retry_count;
+ s32 ret = 0;
+ u8 version;
+
+ if (chip->is_present == is_present)
+ return 0;
+
+ if (!is_present) {
+ chip->is_present = false;
+ /* Disable PEC when no device is present */
+ client->flags &= ~I2C_CLIENT_PEC;
+ return 0;
+ }
+
+ /* Check if device supports packet error checking and use it */
+ while (retries > 0) {
+ ret = i2c_smbus_read_word_data(client, REG_ADDR_SPEC_INFO);
+ if (ret >= 0)
+ break;
+
+ /*
+ * Some batteries trigger the detection pin before the
+ * I2C bus is properly connected. This works around the
+ * issue.
+ */
+ msleep(100);
+
+ retries--;
+ }
+
+ if (ret < 0) {
+ dev_dbg(&client->dev, "failed to read spec info: %d\n", ret);
+
+ /* fallback to old behaviour */
+ client->flags &= ~I2C_CLIENT_PEC;
+ chip->is_present = true;
+
+ return ret;
+ }
+
+ version = (ret & SPEC_INFO_VERSION_MASK) >> SPEC_INFO_VERSION_SHIFT;
+
+ if (version == SBS_VERSION_1_1_WITH_PEC)
+ client->flags |= I2C_CLIENT_PEC;
+ else
+ client->flags &= ~I2C_CLIENT_PEC;
+
+ dev_dbg(&client->dev, "PEC: %s\n", (client->flags & I2C_CLIENT_PEC) ?
+ "enabled" : "disabled");
+
+ chip->is_present = true;
+
+ return 0;
+}
+
static int sbs_read_word_data(struct i2c_client *client, u8 address)
{
struct sbs_info *chip = i2c_get_clientdata(client);
@@ -579,7 +645,7 @@ static int sbs_get_property(struct power_supply *psy,
return ret;
if (psp == POWER_SUPPLY_PROP_PRESENT) {
val->intval = ret;
- chip->is_present = val->intval;
+ sbs_update_presence(chip, ret);
return 0;
}
if (ret == 0)
@@ -678,7 +744,7 @@ static int sbs_get_property(struct power_supply *psy,
if (!chip->gpio_detect &&
chip->is_present != (ret >= 0)) {
- chip->is_present = (ret >= 0);
+ sbs_update_presence(chip, (ret >= 0));
power_supply_changed(chip->power_supply);
}
@@ -709,7 +775,7 @@ static void sbs_supply_changed(struct sbs_info *chip)
ret = gpiod_get_value_cansleep(chip->gpio_detect);
if (ret < 0)
return;
- chip->is_present = ret;
+ sbs_update_presence(chip, ret);
power_supply_changed(battery);
}