[U-Boot] [PATCH v2 5/7] cros: adds cros_ec keyboard driver

[Simon Glass <sjg@chromium.org>]

Hi Hung-ying,

On Mon, Mar 18, 2013 at 9:22 AM, Hung-ying Tyan <tyanh@chromium.org> wrote:
> This patch adds the driver for keyboard that's controlled by ChromeOS EC.
>
> Signed-off-by: Randall Spangler <rspangler@chromium.org>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
> Signed-off-by: Hung-ying Tyan <tyanh@chromium.org>
>
> ---
> Changes in v2:
> - Wrapped lines to comply with the 80-char rule.
>
>  README                       |   5 +
>  drivers/input/Makefile       |   1 +
>  drivers/input/cros_ec_keyb.c | 264 +++++++++++++++++++++++++++++++++++++++++++
>  include/fdtdec.h             |   1 +
>  lib/fdtdec.c                 |   1 +
>  5 files changed, 272 insertions(+)
>  create mode 100644 drivers/input/cros_ec_keyb.c
>
> diff --git a/README b/README
> index 42544ce..769d1bf 100644
> --- a/README
> +++ b/README
> @@ -1371,6 +1371,11 @@ CBFS (Coreboot Filesystem) support
>                 Export function i8042_kbd_init, i8042_tstc and i8042_getc
>                 for cfb_console. Supports cursor blinking.
>
> +               CONFIG_CROS_EC_KEYB
> +               Enables a Chrome OS keyboard using the CROS_EC interface.
> +               This uses CROS_EC to communicate with a second microcontroller
> +               which provides key scans on request.
> +
>  - Video support:
>                 CONFIG_VIDEO
>
> diff --git a/drivers/input/Makefile b/drivers/input/Makefile
> index 0805e86..4331190 100644
> --- a/drivers/input/Makefile
> +++ b/drivers/input/Makefile
> @@ -27,6 +27,7 @@ LIB   := $(obj)libinput.o
>
>  COBJS-$(CONFIG_I8042_KBD) += i8042.o
>  COBJS-$(CONFIG_TEGRA_KEYBOARD) += tegra-kbc.o
> +COBJS-$(CONFIG_CROS_EC_KEYB) += cros_ec_keyb.o
>  ifdef CONFIG_PS2KBD
>  COBJS-y += keyboard.o pc_keyb.o
>  COBJS-$(CONFIG_PS2MULT) += ps2mult.o ps2ser.o
> diff --git a/drivers/input/cros_ec_keyb.c b/drivers/input/cros_ec_keyb.c
> new file mode 100644
> index 0000000..21fab15
> --- /dev/null
> +++ b/drivers/input/cros_ec_keyb.c
> @@ -0,0 +1,264 @@
> +/*
> + * Chromium OS Matrix Keyboard
> + *
> + * Copyright (c) 2012 The Chromium OS Authors.
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +#include <fdtdec.h>
> +#include <input.h>
> +#include <key_matrix.h>
> +#include <cros_ec.h>

Please put this after common.h so it is in alphabetical order.

> +#include <stdio_dev.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +enum {
> +       KBC_MAX_KEYS            = 8,    /* Maximum keys held down at once */
> +};
> +
> +static struct keyb {
> +       struct cros_ec_dev *dev;                /* The CROS_EC device */
> +       struct input_config input;      /* The input layer */
> +       struct key_matrix matrix;       /* The key matrix layer */
> +       int key_rows;                   /* Number of keyboard rows */
> +       int key_cols;                   /* Number of keyboard columns */
> +       unsigned int repeat_delay_ms;   /* Time before autorepeat starts */
> +       unsigned int repeat_rate_ms;    /* Autorepeat rate in ms */
> +       int ghost_filter;               /* 1 to enable ghost filter, else 0 */
> +       int inited;                     /* 1 if keyboard is ready */
> +} config;
> +
> +
> +/**
> + * Check the keyboard controller and return a list of key matrix positions
> + * for which a key is pressed
> + *
> + * @param config       Keyboard config
> + * @param keys         List of keys that we have detected
> + * @param max_count    Maximum number of keys to return
> + * @return number of pressed keys, 0 for none
> + */
> +static int check_for_keys(struct keyb *config,
> +                          struct key_matrix_key *keys, int max_count)
> +{
> +       struct key_matrix_key *key;
> +       struct mbkp_keyscan scan;
> +       unsigned int row, col, bit, data;
> +       int num_keys;
> +
> +       if (cros_ec_scan_keyboard(config->dev, &scan)) {
> +               debug("%s: keyboard scan failed\n", __func__);
> +               return -1;
> +       }
> +
> +       /* TODO(sjg at chromium,org): Should perhaps optimize this algorithm */

I think we can remove this TODO now.

> +       for (col = num_keys = bit = 0; col < config->matrix.num_cols;
> +                       col++) {
> +               for (row = 0; row < config->matrix.num_rows; row++) {
> +                       unsigned int mask = 1 << (bit & 7);
> +
> +                       data = scan.data[bit / 8];
> +                       if ((data & mask) && num_keys < max_count) {
> +                               key = keys + num_keys++;
> +                               key->row = row;
> +                               key->col = col;
> +                               key->valid = 1;
> +                       }
> +                       bit++;
> +               }
> +       }
> +
> +       return num_keys;
> +}
> +
> +/**
> + * Test if keys are available to be read
> + *
> + * @return 0 if no keys available, 1 if keys are available
> + */
> +static int kbd_tstc(void)
> +{
> +       /* Just get input to do this for us */
> +       return config.inited ? input_tstc(&config.input) : 0;
> +}
> +
> +/**
> + * Read a key
> + *
> + * @return ASCII key code, or 0 if no key, or -1 if error
> + */
> +static int kbd_getc(void)
> +{
> +       /* Just get input to do this for us */
> +       return config.inited ? input_getc(&config.input) : 0;
> +}
> +
> +/**
> + * Check the keyboard, and send any keys that are pressed.
> + *
> + * This is called by input_tstc() and input_getc() when they need more
> + * characters
> + *
> + * @param input                Input configuration
> + * @return 1, to indicate that we have something to look at
> + */
> +int cros_ec_kbc_check(struct input_config *input)
> +{
> +       static struct key_matrix_key last_keys[KBC_MAX_KEYS];
> +       static int last_num_keys;
> +       struct key_matrix_key keys[KBC_MAX_KEYS];
> +       int keycodes[KBC_MAX_KEYS];
> +       int num_keys, num_keycodes;
> +       int irq_pending, sent;
> +
> +       /*
> +        * crosbug.com/p/13864

You can remove this bug reference as it is not relevant.

> +        *
> +        * Loop until the EC has no more keyscan records, or we have
> +        * received at least one character. This means we know that tstc()
> +        * will always return non-zero if keys have been pressed.
> +        *
> +        * Without this loop, a key release (which generates no new ascii
> +        * characters) will cause us to exit this function, and just tstc()
> +        * may return 0 before all keys have been read from the EC.
> +        */
> +       do {
> +               irq_pending = cros_ec_interrupt_pending(config.dev);
> +               if (irq_pending) {
> +                       num_keys = check_for_keys(&config, keys, KBC_MAX_KEYS);
> +                       last_num_keys = num_keys;
> +                       memcpy(last_keys, keys, sizeof(keys));
> +               } else {
> +                       /*
> +                        * EC doesn't want to be asked, so use keys from last
> +                        * time.
> +                        */
> +                       num_keys = last_num_keys;
> +                       memcpy(keys, last_keys, sizeof(keys));
> +               }
> +
> +               if (num_keys < 0)
> +                       return -1;
> +               num_keycodes = key_matrix_decode(&config.matrix, keys,
> +                               num_keys, keycodes, KBC_MAX_KEYS);
> +               sent = input_send_keycodes(input, keycodes, num_keycodes);
> +       } while (irq_pending && !sent);
> +
> +       return 1;
> +}
> +
> +/**
> + * Decode MBKP keyboard details from the device tree
> + *
> + * @param blob         Device tree blob
> + * @param node         Node to decode from
> + * @param config       Configuration data read from fdt
> + * @return 0 if ok, -1 on error
> + */
> +static int cros_ec_keyb_decode_fdt(const void *blob, int node,
> +                               struct keyb *config)
> +{
> +       /*
> +        * Get keyboard rows and columns - at present we are limited to
> +        * 8 columns by the protocol (one byte per row scan)
> +        */
> +       config->key_rows = fdtdec_get_int(blob, node, "google,key-rows", 0);
> +       config->key_cols = fdtdec_get_int(blob, node, "google,key-columns", 0);
> +       if (!config->key_rows || !config->key_cols ||
> +                       config->key_rows * config->key_cols / 8
> +                               > CROS_EC_KEYSCAN_COLS) {
> +               debug("%s: Invalid key matrix size %d x %d\n", __func__,
> +                     config->key_rows, config->key_cols);
> +               return -1;
> +       }
> +       config->repeat_delay_ms = fdtdec_get_int(blob, node,
> +                                                "google,repeat-delay-ms", 0);
> +       config->repeat_rate_ms = fdtdec_get_int(blob, node,
> +                                               "google,repeat-rate-ms", 0);
> +       config->ghost_filter = fdtdec_get_bool(blob, node,
> +                                              "google,ghost-filter");
> +       return 0;
> +}
> +
> +/**
> + * Set up the keyboard. This is called by the stdio device handler.
> + *
> + * We want to do this init when the keyboard is actually used rather than
> + * at start-up, since keyboard input may not currently be selected.
> + *
> + * @return 0 if ok, -1 on error
> + */
> +static int cros_ec_init_keyboard(void)
> +{
> +       const void *blob = gd->fdt_blob;
> +       int node;
> +
> +       config.dev = board_get_cros_ec_dev();
> +       if (!config.dev) {
> +               debug("%s: no cros_ec device: cannot init keyboard\n",
> +                     __func__);
> +               return -1;
> +       }
> +       node = fdtdec_next_compatible(blob, 0, COMPAT_GOOGLE_CROS_EC_KEYB);
> +       if (node < 0) {
> +               debug("%s: Node not found\n", __func__);
> +               return -1;
> +       }
> +       if (cros_ec_keyb_decode_fdt(blob, node, &config))
> +               return -1;
> +       input_set_delays(&config.input, config.repeat_delay_ms,
> +                        config.repeat_rate_ms);
> +       if (key_matrix_init(&config.matrix, config.key_rows,
> +                       config.key_cols, config.ghost_filter)) {
> +               debug("%s: cannot init key matrix\n", __func__);
> +               return -1;
> +       }
> +       if (key_matrix_decode_fdt(&config.matrix, gd->fdt_blob, node)) {
> +               debug("%s: Could not decode key matrix from fdt\n", __func__);
> +               return -1;
> +       }
> +       config.inited = 1;
> +       debug("%s: Matrix keyboard %dx%d ready\n", __func__, config.key_rows,
> +             config.key_cols);
> +
> +       return 0;
> +}
> +
> +int drv_keyboard_init(void)
> +{
> +       struct stdio_dev dev;
> +
> +       if (input_init(&config.input, 0)) {
> +               debug("%s: Cannot set up input\n", __func__);
> +               return -1;
> +       }
> +       config.input.read_keys = cros_ec_kbc_check;
> +
> +       memset(&dev, '\0', sizeof(dev));
> +       strcpy(dev.name, "cros-ec-keyb");
> +       dev.flags = DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM;
> +       dev.getc = kbd_getc;
> +       dev.tstc = kbd_tstc;
> +       dev.start = cros_ec_init_keyboard;
> +
> +       /* Register the device. cros_ec_init_keyboard() will be called soon */
> +       return input_stdio_register(&dev);
> +}
> diff --git a/include/fdtdec.h b/include/fdtdec.h
> index 0f4bbaa..0eaabe1 100644
> --- a/include/fdtdec.h
> +++ b/include/fdtdec.h
> @@ -79,6 +79,7 @@ enum fdt_compat_id {
>         COMPAT_WOLFSON_WM8994_CODEC,    /* Wolfson WM8994 Sound Codec */
>         COMPAT_SAMSUNG_EXYNOS_SPI,      /* Exynos SPI */
>         COMPAT_GOOGLE_CROS_EC,          /* Google CROS_EC Protocol */
> +       COMPAT_GOOGLE_CROS_EC_KEYB,     /* Google CROS_EC Keyboard */
>         COMPAT_SAMSUNG_EXYNOS_EHCI,     /* Exynos EHCI controller */
>         COMPAT_SAMSUNG_EXYNOS_USB_PHY,  /* Exynos phy controller for usb2.0 */
>         COMPAT_MAXIM_MAX77686_PMIC,     /* MAX77686 PMIC */
> diff --git a/lib/fdtdec.c b/lib/fdtdec.c
> index 24cd6f9..df60bee 100644
> --- a/lib/fdtdec.c
> +++ b/lib/fdtdec.c
> @@ -54,6 +54,7 @@ static const char * const compat_names[COMPAT_COUNT] = {
>         COMPAT(WOLFSON_WM8994_CODEC, "wolfson,wm8994-codec"),
>         COMPAT(SAMSUNG_EXYNOS_SPI, "samsung,exynos-spi"),
>         COMPAT(GOOGLE_CROS_EC, "google,cros-ec"),
> +       COMPAT(GOOGLE_CROS_EC_KEYB, "google,cros-ec-keyb"),
>         COMPAT(SAMSUNG_EXYNOS_EHCI, "samsung,exynos-ehci"),
>         COMPAT(SAMSUNG_EXYNOS_USB_PHY, "samsung,exynos-usb-phy"),
>         COMPAT(MAXIM_MAX77686_PMIC, "maxim,max77686_pmic"),
> --
> 1.8.1.3
>

Otherwise looks good to me.

Regards,
Simon