From aa99830c067036015b6ce45c01063b4482bf05b9 Mon Sep 17 00:00:00 2001 From: Maxim Polyakov Date: Sat, 20 Jun 2020 17:26:21 +0300 Subject: ec/kontron/kempld: add option to configure I2C frequency Allows to change the I2C bus frequency by overriding i2c_frequency option from the board devicetree. Thus, the I2C controller can use Fast-mode (Fm), with a bit rate up to 400 kbit/s and Fast-mode Plus (Fm+), with a bit rate up to 1 Mbit/s [1]. Tested on Kontron mAL10 COMe module with T10-TNI carrierboard [2]. [1] I2C-bus specification and user manual, doc #UM10204, Rev. 6, 4 April 2014. [2] https://review.coreboot.org/c/coreboot/+/39133 Change-Id: If0eb477af10d00eb4f17f9c01209f170b746ad3d Signed-off-by: Maxim Polyakov Reviewed-on: https://review.coreboot.org/c/coreboot/+/44476 Reviewed-by: Angel Pons Reviewed-by: Nico Huber Tested-by: build bot (Jenkins) --- src/ec/kontron/kempld/chip.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'src/ec/kontron/kempld/chip.h') diff --git a/src/ec/kontron/kempld/chip.h b/src/ec/kontron/kempld/chip.h index 8ca8d246e9..30f40fe097 100644 --- a/src/ec/kontron/kempld/chip.h +++ b/src/ec/kontron/kempld/chip.h @@ -12,6 +12,13 @@ enum kempld_uart_io { KEMPLD_UART_2E8 = 3, }; +enum kempld_i2c_frequency { + KEMPLD_I2C_FREQ_STANDARD_MODE_100KHZ = 100, + KEMPLD_I2C_FREQ_FAST_MODE_400KHZ = 400, + KEMPLD_I2C_FREQ_FAST_PLUS_MODE_1MHZ = 1000, + KEMPLD_I2C_FREQ_MAX = 2700, +}; + struct kempld_uart { enum kempld_uart_io io; unsigned int irq; @@ -19,6 +26,7 @@ struct kempld_uart { struct ec_kontron_kempld_config { struct kempld_uart uart[KEMPLD_NUM_UARTS]; + unsigned short i2c_frequency; }; #endif /* EC_KONTRON_KEMPLD_CHIP_H */ -- cgit v1.2.3