Reland "smart_battery: add smbus error checking support"

This is a reland of daccb3adea9394116d7ab2c807e4a360cb5a93a1

Original change's description:
> smart_battery: add smbus error checking support
>
> Jacuzzi/Kodama has a unstable software controlled i2c bus, its data
> transmission may be interrupted by other higher priority tasks and
> causes device timeout.
>
> If timeout happens when ec is reading data, it has no knowledge about
> what's happening on slave, and keep receiving bad data (0xFF's) until
> end. The standard i2c/smbus error handling mechanism can not handle this
> case, so we need the error checking feature from smbus 1.1 to ensure our
> received data is correct.
>
> This CL adds the error checking (PEC) functions to i2c and smart battery
> module.
>
> BUG=b:138415463
> TEST=On kodama, enable CONFIG_CMD_I2C_STRESS_TEST,
>      no failure after 100k read/writes.
>      test code at CL:1865054
> BRANCH=master
>
> Change-Id: Ibb9ad3aa03d7690a08f59c617c2cd9c1b9cb0ff3
> Signed-off-by: Ting Shen <phoenixshen@google.com>
> Reviewed-on: http://crrev.com/c/1827138
> Reviewed-by: Denis Brockus <dbrockus@chromium.org>
> Tested-by: Ting Shen <phoenixshen@chromium.org>
> Commit-Queue: Ting Shen <phoenixshen@chromium.org>

BUG=b:138415463
TEST=in addition to the TESTs above, verified this CL boots on
     hatch(npcx chips), and reef_it8320(it83xx chips).
BRANCH=master

Change-Id: I67975eee677cfd6e383742d48103662372cac061
Signed-off-by: Ting Shen <phoenixshen@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1913940
Commit-Queue: Ting Shen <phoenixshen@chromium.org>
Tested-by: Ting Shen <phoenixshen@chromium.org>
Reviewed-by: Denis Brockus <dbrockus@chromium.org>

1 files changed, 43 insertions, 8 deletions

diff --git a/driver/battery/smart.c b/driver/battery/smart.c
index a2527db42f..14106664cb 100644
--- a/driver/battery/smart.c
+++ b/driver/battery/smart.c
@@ -22,8 +22,32 @@
 static int fake_state_of_charge = -1;
 static int fake_temperature = -1;
 
+static int battery_supports_pec(void)
+{
+	static int supports_pec = -1;
+
+	if (!IS_ENABLED(CONFIG_SMBUS_PEC))
+		return 0;
+
+	if (supports_pec < 0) {
+		int spec_info;
+		int rv = i2c_read16(I2C_PORT_BATTERY, BATTERY_ADDR_FLAGS,
+				    SB_SPECIFICATION_INFO, &spec_info);
+		/* failed, assuming not support and try again later */
+		if (rv)
+			return 0;
+
+		supports_pec = (BATTERY_SPEC_VERSION(spec_info) ==
+				BATTERY_SPEC_VER_1_1_WITH_PEC);
+		CPRINTS("battery supports pec: %d", supports_pec);
+	}
+	return supports_pec;
+}
+
 test_mockable int sb_read(int cmd, int *param)
 {
+	uint16_t addr_flags = BATTERY_ADDR_FLAGS;
+
 #ifdef CONFIG_BATTERY_CUT_OFF
 	/*
 	 * Some batteries would wake up after cut-off if we talk to it.
@@ -31,13 +55,16 @@ test_mockable int sb_read(int cmd, int *param)
 	if (battery_is_cut_off())
 		return EC_RES_ACCESS_DENIED;
 #endif
+	if (battery_supports_pec())
+		addr_flags |= I2C_FLAG_PEC;
 
-	return i2c_read16(I2C_PORT_BATTERY, BATTERY_ADDR_FLAGS,
-			  cmd, param);
+	return i2c_read16(I2C_PORT_BATTERY, addr_flags, cmd, param);
 }
 
 test_mockable int sb_write(int cmd, int param)
 {
+	uint16_t addr_flags = BATTERY_ADDR_FLAGS;
+
 #ifdef CONFIG_BATTERY_CUT_OFF
 	/*
 	 * Some batteries would wake up after cut-off if we talk to it.
@@ -45,13 +72,16 @@ test_mockable int sb_write(int cmd, int param)
 	if (battery_is_cut_off())
 		return EC_RES_ACCESS_DENIED;
 #endif
+	if (battery_supports_pec())
+		addr_flags |= I2C_FLAG_PEC;
 
-	return i2c_write16(I2C_PORT_BATTERY, BATTERY_ADDR_FLAGS,
-			   cmd, param);
+	return i2c_write16(I2C_PORT_BATTERY, addr_flags, cmd, param);
 }
 
 int sb_read_string(int offset, uint8_t *data, int len)
 {
+	uint16_t addr_flags = BATTERY_ADDR_FLAGS;
+
 #ifdef CONFIG_BATTERY_CUT_OFF
 	/*
 	 * Some batteries would wake up after cut-off if we talk to it.
@@ -59,9 +89,10 @@ int sb_read_string(int offset, uint8_t *data, int len)
 	if (battery_is_cut_off())
 		return EC_RES_ACCESS_DENIED;
 #endif
+	if (battery_supports_pec())
+		addr_flags |= I2C_FLAG_PEC;
 
-	return i2c_read_string(I2C_PORT_BATTERY, BATTERY_ADDR_FLAGS,
-			       offset, data, len);
+	return i2c_read_string(I2C_PORT_BATTERY, addr_flags, offset, data, len);
 }
 
 int sb_read_mfgacc(int cmd, int block, uint8_t *data, int len)
@@ -96,6 +127,8 @@ int sb_read_mfgacc(int cmd, int block, uint8_t *data, int len)
 
 int sb_write_block(int reg, const uint8_t *val, int len)
 {
+	uint16_t addr_flags = BATTERY_ADDR_FLAGS;
+
 #ifdef CONFIG_BATTERY_CUT_OFF
 	/*
 	 * Some batteries would wake up after cut-off if we talk to it.
@@ -104,9 +137,11 @@ int sb_write_block(int reg, const uint8_t *val, int len)
 		return EC_RES_ACCESS_DENIED;
 #endif
 
+	if (battery_supports_pec())
+		addr_flags |= I2C_FLAG_PEC;
+
 	/* TODO: implement smbus_write_block. */
-	return i2c_write_block(I2C_PORT_BATTERY, BATTERY_ADDR_FLAGS,
-			       reg, val, len);
+	return i2c_write_block(I2C_PORT_BATTERY, addr_flags, reg, val, len);
 }
 
 int battery_get_mode(int *mode)