From: Denis Zalevskiy denis.zalevskiy@ge.com
If there is an I2C mux, current bus should be switched before manipulating with I2C.
Signed-off-by: Denis Zalevskiy denis.zalevskiy@ge.com Signed-off-by: Fabien Lahoudere fabien.lahoudere@collabora.com --- drivers/bootcount/Kconfig | 15 ++++++++- drivers/bootcount/bootcount_i2c.c | 71 ++++++++++++++++++++++++++++++++++----- 2 files changed, 77 insertions(+), 9 deletions(-)
diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig index 9a0bd51..f67f518 100644 --- a/drivers/bootcount/Kconfig +++ b/drivers/bootcount/Kconfig @@ -62,7 +62,9 @@ config BOOTCOUNT_I2C bool "Boot counter on I2C device" help Enable support for the bootcounter on an i2c (like RTC) device. - CONFIG_SYS_I2C_RTC_ADDR = i2c chip address + CONFIG_SYS_BOOTCOUNT_I2C_BUS = bus of the target I2C device, + CONFIG_SYS_I2C_RTC_ADDR is used as fallback + CONFIG_SYS_BOOTCOUNT_I2C_ADDR = target I2C device address CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for the bootcounter.
@@ -127,4 +129,15 @@ config SYS_BOOTCOUNT_ADDR help Set the address used for reading and writing the boot counter.
+config SYS_BOOTCOUNT_I2C_BUS + int "I2C bootcounter device bus" + depends on BOOTCOUNT_I2C + help + I2C bus of the device used to store bootcounter + +config SYS_BOOTCOUNT_I2C_ADDR + hex "I2C bootcounter device address" + depends on BOOTCOUNT_I2C + help + I2C address of the device used to store bootcounter endif diff --git a/drivers/bootcount/bootcount_i2c.c b/drivers/bootcount/bootcount_i2c.c index 496741d..a1fc219 100644 --- a/drivers/bootcount/bootcount_i2c.c +++ b/drivers/bootcount/bootcount_i2c.c @@ -8,36 +8,91 @@ #include <linux/compiler.h> #include <i2c.h>
+#ifndef CONFIG_SYS_BOOTCOUNT_I2C_ADDR +/* compatibility with the previous logic: + * previous version of driver used RTC device to store bootcount + */ +#define CONFIG_SYS_BOOTCOUNT_I2C_ADDR CONFIG_SYS_I2C_RTC_ADDR +#endif + #define BC_MAGIC 0xbc
+#ifdef CONFIG_SYS_BOOTCOUNT_I2C_BUS +static int bootcount_set_bus(void) +{ + unsigned int current_bus = i2c_get_bus_num(); + + assert(current_bus <= INT_MAX); + + int res = i2c_set_bus_num(CONFIG_SYS_BOOTCOUNT_I2C_BUS); + + if (res < 0) { + puts("Error switching I2C bus\n"); + return res; + } + return (int)current_bus; +} + +static void bootcount_set_bus_back(int prev_bus) +{ + if (i2c_set_bus_num(prev_bus) < 0) + puts("Can't switch I2C bus back\n"); +} +#else +static inline void bootcount_set_bus(void) { return ; } + +static inline int bootcount_set_bus_back(int prev_bus __attribute__((unused))) +{ + return 0; +} +#endif + void bootcount_store(ulong a) { + int prev_i2c_bus = bootcount_set_bus(); + + if (prev_i2c_bus < 0) + return; + unsigned char buf[3]; int ret;
buf[0] = BC_MAGIC; buf[1] = (a & 0xff); - ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, CONFIG_SYS_BOOTCOUNT_ADDR, - CONFIG_BOOTCOUNT_ALEN, buf, 2); + ret = i2c_write(CONFIG_SYS_BOOTCOUNT_I2C_ADDR, + CONFIG_SYS_BOOTCOUNT_ADDR, + CONFIG_BOOTCOUNT_ALEN, buf, 2); if (ret != 0) puts("Error writing bootcount\n"); + + bootcount_set_bus_back(prev_i2c_bus); }
ulong bootcount_load(void) { + ulong count = 0; + + int prev_i2c_bus = bootcount_set_bus(); + + if (prev_i2c_bus < 0) + return count; + unsigned char buf[3]; int ret;
- ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, CONFIG_SYS_BOOTCOUNT_ADDR, + ret = i2c_read(CONFIG_SYS_BOOTCOUNT_I2C_ADDR, + CONFIG_SYS_BOOTCOUNT_ADDR, CONFIG_BOOTCOUNT_ALEN, buf, 2); if (ret != 0) { puts("Error loading bootcount\n"); - return 0; + goto out; } if (buf[0] == BC_MAGIC) - return buf[1]; - - bootcount_store(0); + count = buf[1]; + else + bootcount_store(count);
- return 0; +out: + bootcount_set_bus_back(prev_i2c_bus); + return count; }