From aad4651e3eab260c94058536d373b2ff22b40d92 Mon Sep 17 00:00:00 2001 From: Yidi Lin Date: Fri, 20 Nov 2020 14:03:20 +0800 Subject: mb/google/asurada: Get RAM code from ADC 3 On Chromebooks the RAM code is implemented by the resistor straps that we can read and decode from ADC. For Asurada the RAM code can be read from ADC channel 3. Signed-off-by: CK Hu Signed-off-by: Yidi Lin Change-Id: Iaadabea1b6aa91c48b137f7c6784ab7ee0adc473 Reviewed-on: https://review.coreboot.org/c/coreboot/+/46391 Tested-by: build bot (Jenkins) Reviewed-by: Hung-Te Lin Reviewed-by: Angel Pons --- src/mainboard/google/asurada/boardid.c | 57 +++++++++++++++++++++++++++++++++- 1 file changed, 56 insertions(+), 1 deletion(-) (limited to 'src/mainboard/google/asurada') diff --git a/src/mainboard/google/asurada/boardid.c b/src/mainboard/google/asurada/boardid.c index 2c8efcddd8..cb91812bbf 100644 --- a/src/mainboard/google/asurada/boardid.c +++ b/src/mainboard/google/asurada/boardid.c @@ -1,9 +1,59 @@ /* SPDX-License-Identifier: GPL-2.0-only */ +#include #include +#include +#include /* board_id is provided by ec/google/chromeec/ec_boardid.c */ +#define ADC_LEVELS 15 + +enum { + RAM_ID_CHANNEL = 3, +}; + +static const unsigned int ram_voltages[ADC_LEVELS] = { + /* ID : Voltage (unit: uV) */ + [0] = 74300, + [1] = 211700, + [2] = 318800, + [3] = 428600, + [4] = 541700, + [5] = 665800, + [6] = 781400, + [7] = 900000, + [8] = 1023100, + [9] = 1137000, + [10] = 1240000, + [11] = 1342600, + [12] = 1457500, + [13] = 1575600, + [14] = 1683600, +}; + +static const unsigned int *adc_voltages[] = { + [RAM_ID_CHANNEL] = ram_voltages, +}; + +static uint32_t get_adc_index(unsigned int channel) +{ + unsigned int value = auxadc_get_voltage_uv(channel); + + assert(channel < ARRAY_SIZE(adc_voltages)); + const unsigned int *voltages = adc_voltages[channel]; + assert(voltages); + + /* Find the closest voltage */ + uint32_t id; + for (id = 0; id < ADC_LEVELS - 1; id++) + if (value < (voltages[id] + voltages[id + 1]) / 2) + break; + + printk(BIOS_DEBUG, "ADC[%u]: Raw value=%u ID=%u\n", channel, value, id); + return id; +} + uint32_t sku_id(void) { return 0; @@ -11,5 +61,10 @@ uint32_t sku_id(void) uint32_t ram_code(void) { - return 0; + static uint32_t cached_ram_code = BOARD_ID_INIT; + + if (cached_ram_code == BOARD_ID_INIT) + cached_ram_code = get_adc_index(RAM_ID_CHANNEL); + + return cached_ram_code; } -- cgit v1.2.3