diff options
| -rw-r--r-- | docs/zephyr_poc_device_bringup.md | 5 | ||||
| -rw-r--r-- | util/gpios_to_zephyr_dts.c | 115 |
2 files changed, 120 insertions, 0 deletions
diff --git a/docs/zephyr_poc_device_bringup.md b/docs/zephyr_poc_device_bringup.md index e61ca57e2c..394aa4a05b 100644 --- a/docs/zephyr_poc_device_bringup.md +++ b/docs/zephyr_poc_device_bringup.md @@ -20,6 +20,11 @@ An example CL to do this for Lazor can be found After you have UART functioning, GPIOs can be an easy target to start unblocking further features. +We have a very ugly program to auto-generate the GPIO DTS based on +gpio.inc for the existing board. You can find it at +`util/gpios_to_zephyr_dts.c`, and instructions are in the file on how +to compile and use it. You may have to hand-modify the output. + The resultant CL for Lazor can be found [here](https://crrev.com/c/2749768). ## Bring up Host Commands diff --git a/util/gpios_to_zephyr_dts.c b/util/gpios_to_zephyr_dts.c new file mode 100644 index 0000000000..38fbaca7ad --- /dev/null +++ b/util/gpios_to_zephyr_dts.c @@ -0,0 +1,115 @@ +/* Copyright 2021 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +/* + * This code is intended for developer use to convert a CrOS EC OS + * "gpio.inc" file into the expected device-tree format for Zephyr. + * The only use of it is to do a proof-of-concept build of a CrOS EC + * device using Zephyr OS, as Zephyr-only devices won't have a + * equivalent CrOS EC build. + * + * It does not handle all cases (i.e., low voltage selection), and + * some manual modifications to the output may be required. + * + ********************************************************************** + * DO NOT CREATE TESTS, SYSTEMS, OR INFRASTRUCTURE WHICH RELIES ON * + * THIS CODE. It's seriously ugly code that's probably prone to * + * breakage. It leaks memory. In other words, consider it * + * "contrib-quality" code that should be deleted one day (once we are * + * no longer doing proof-of-concept Zephyr builds). * + ********************************************************************** + * + * To compile: + * gcc -Iboard/${BOARD} -std=gnu11 util/gpios_to_zephyr_dts.c \ + * -o /tmp/print_gpios + * + * Then run /tmp/print_gpios and paste the result into your gpio DTS + * overlay. + */ + +#define _POSIX_C_SOURCE 200809L + +#include <ctype.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +/* + * Implement the macros used in the gpio.inc files, but print DTS + * format equivalents. + */ +#define GPIO_INT_RISING GPIO_INPUT +#define GPIO_INT_FALLING GPIO_INPUT +#define GPIO_INT_BOTH GPIO_INPUT +#define GPIO_HIB_WAKE_HIGH 0 +#define GPIO_HIB_WAKE_LOW 0 +#define GPIO_LOCKED 0 +#define GPIO_SEL_1P8V 0 +#define GPIO_INT(name, pin, opts, int) GPIO(name, pin, opts) +#define GPIO(name, pin, opts) _gpio(#name, pin, opts) +#define UNUSED(pin) +#define UNIMPLEMENTED(name) +#define _gpio(name, pin, opts) \ + printf("%s {\n\tgpios = <&%s %s>;\n\tlabel = %s;\n};\n", \ + strlower(name), strlower(pin), \ + maybe_parens(strip_zero_ors(#opts)), #name); +#define PIN(A, B) "gpio" #A " " #B +#define ALTERNATE(...) + +/* Strip out " | 0" and "0 | " from a string */ +static char *strip_zero_ors(const char *s) +{ + char *out = malloc(strlen(s) + 2); + const char *rd_ptr = s; + char *wr_ptr = out; + + while (*rd_ptr) { + if (!strncmp(rd_ptr, " | 0", 4) || + !strncmp(rd_ptr, "0 | ", 4)) { + rd_ptr += 4; + } else { + *wr_ptr = *rd_ptr; + rd_ptr++; + wr_ptr++; + } + } + + *wr_ptr = '\0'; + return out; +} + +/* + * Add parenthesis around the outside of a string if it contains the + * '|' character. + */ +static char *maybe_parens(const char *s) +{ + size_t out_sz = strlen(s) + 3; + char *out = malloc(out_sz); + + if (strchr(s, '|')) + snprintf(out, out_sz, "(%s)", s); + else + snprintf(out, out_sz, "%s", s); + + return out; +} + +/* Convert a string to lowercase */ +static char *strlower(const char *s) +{ + char *out = strdup(s); + + for (int i = 0; out[i]; i++) + out[i] = tolower(out[i]); + + return out; +} + +int main(int argc, char *argv[]) +{ +#include "gpio.inc" + return 0; +} |