From 22c040fa21b604b9b3d88645e108fb2f0a74474b Mon Sep 17 00:00:00 2001 From: Enric Balletbo i Serra Date: Fri, 14 Jun 2019 23:43:01 +0200 Subject: platform/chrome: cros_ec_lpc: Choose Microchip EC at runtime On many boards, communication between the kernel and the Embedded Controller happens over an LPC bus. In these cases, the kernel config CONFIG_CROS_EC_LPC is enabled. Some of these LPC boards contain a Microchip Embedded Controller (MEC) that is different from the regular EC. On these devices, the same LPC bus is used, but the protocol is a little different. In these cases, the CONFIG_CROS_EC_LPC_MEC kernel config is enabled. Currently, the kernel decides at compile-time whether or not to use the MEC variant, and, when that kernel option is selected it breaks the other boards. We would like a kind of runtime detection to avoid this. This patch adds that detection mechanism by probing the protocol at runtime, first we assume that a MEC variant is connected, and if the protocol fails it fallbacks to the regular EC. This adds a bit of overload because we try to read twice on those LPC boards that doesn't contain a MEC variant, but is a better solution than having to select the EC variant at compile-time. While here also fix the alignment in Kconfig file for this config option replacing the spaces by tabs. Signed-off-by: Enric Balletbo i Serra Reviewed-by: Ezequiel Garcia Tested-by: Nick Crews Reviewed-by: Nick Crews --- drivers/platform/chrome/Makefile | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/platform/chrome/Makefile') diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile index 5a2bcef4b07c..fd0af05cc14c 100644 --- a/drivers/platform/chrome/Makefile +++ b/drivers/platform/chrome/Makefile @@ -10,8 +10,7 @@ obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o obj-$(CONFIG_CROS_EC_ISHTP) += cros_ec_ishtp.o obj-$(CONFIG_CROS_EC_RPMSG) += cros_ec_rpmsg.o obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o -cros_ec_lpcs-objs := cros_ec_lpc.o -cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o +cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_mec.o obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o obj-$(CONFIG_CROS_EC_PROTO) += cros_ec_proto.o cros_ec_trace.o obj-$(CONFIG_CROS_KBD_LED_BACKLIGHT) += cros_kbd_led_backlight.o -- cgit v1.2.3-59-g8ed1b