[U-Boot] [PATCH V3] i.MX6Q: mx6qsabrelite: Add keypress support to alter boot flow

[Marek Vasut <marex@denx.de>]

Dear Eric Nelson,

> Uses the 'magic_keys' idiom as described in doc/README.kbd:
> 	http://lists.denx.de/pipermail/u-boot/2012-April/122502.html
> 
> Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>

Acked-by: Marek Vasut <marex@denx.de>
> ---
> V2 based on suggestion by Wolfgang to follow prior implementations.
> V3 fixes style issues highlighted by Marek Vasut.
> 
>  board/freescale/mx6qsabrelite/mx6qsabrelite.c |  121
> ++++++++++++++++++++++++- include/configs/mx6qsabrelite.h               | 
>   3 +
>  2 files changed, 122 insertions(+), 2 deletions(-)
> 
> diff --git a/board/freescale/mx6qsabrelite/mx6qsabrelite.c
> b/board/freescale/mx6qsabrelite/mx6qsabrelite.c index 1d09a72..3684216
> 100644
> --- a/board/freescale/mx6qsabrelite/mx6qsabrelite.c
> +++ b/board/freescale/mx6qsabrelite/mx6qsabrelite.c
> @@ -50,6 +50,10 @@ DECLARE_GLOBAL_DATA_PTR;
>  	PAD_CTL_PUS_100K_DOWN | PAD_CTL_SPEED_MED |		\
>  	PAD_CTL_DSE_40ohm     | PAD_CTL_SRE_FAST)
> 
> +#define BUTTON_PAD_CTRL (PAD_CTL_PKE | PAD_CTL_PUE |		\
> +	PAD_CTL_PUS_100K_UP | PAD_CTL_SPEED_MED   |		\
> +	PAD_CTL_DSE_40ohm   | PAD_CTL_HYS)
> +
>  int dram_init(void)
>  {
>         gd->ram_size = get_ram_size((void *)PHYS_SDRAM, PHYS_SDRAM_SIZE);
> @@ -122,6 +126,22 @@ iomux_v3_cfg_t enet_pads2[] = {
>  	MX6Q_PAD_RGMII_RX_CTL__RGMII_RX_CTL	| MUX_PAD_CTRL(ENET_PAD_CTRL),
>  };
> 
> +/* Button assignments for J14 */
> +static iomux_v3_cfg_t button_pads[] = {
> +	/* Menu */
> +	MX6Q_PAD_NANDF_D1__GPIO_2_1	| MUX_PAD_CTRL(BUTTON_PAD_CTRL),
> +	/* Back */
> +	MX6Q_PAD_NANDF_D2__GPIO_2_2	| MUX_PAD_CTRL(BUTTON_PAD_CTRL),
> +	/* Labelled Search (mapped to Power under Android) */
> +	MX6Q_PAD_NANDF_D3__GPIO_2_3	| MUX_PAD_CTRL(BUTTON_PAD_CTRL),
> +	/* Home */
> +	MX6Q_PAD_NANDF_D4__GPIO_2_4	| MUX_PAD_CTRL(BUTTON_PAD_CTRL),
> +	/* Volume Down */
> +	MX6Q_PAD_GPIO_19__GPIO_4_5	| MUX_PAD_CTRL(BUTTON_PAD_CTRL),
> +	/* Volume Up */
> +	MX6Q_PAD_GPIO_18__GPIO_7_13	| MUX_PAD_CTRL(BUTTON_PAD_CTRL),
> +};
> +
>  static void setup_iomux_enet(void)
>  {
>  	gpio_direction_output(87, 0);  /* GPIO 3-23 */
> @@ -267,11 +287,18 @@ int board_eth_init(bd_t *bis)
>  	return 0;
>  }
> 
> +static void setup_buttons(void)
> +{
> +	imx_iomux_v3_setup_multiple_pads(button_pads,
> +					 ARRAY_SIZE(button_pads));
> +}
> +
>  int board_early_init_f(void)
>  {
> -       setup_iomux_uart();
> +	setup_iomux_uart();
> +	setup_buttons();
> 
> -       return 0;
> +	return 0;
>  }
> 
>  int board_init(void)
> @@ -292,3 +319,93 @@ int checkboard(void)
> 
>         return 0;
>  }
> +
> +struct button_key {
> +	char const	*name;
> +	unsigned	gpnum;
> +	char		ident;
> +};
> +
> +static struct button_key const buttons[] = {
> +	{"back",	GPIO_NUMBER(2, 2),	'B'},
> +	{"home",	GPIO_NUMBER(2, 4),	'H'},
> +	{"menu",	GPIO_NUMBER(2, 1),	'M'},
> +	{"search",	GPIO_NUMBER(2, 3),	'S'},
> +	{"volup",	GPIO_NUMBER(7, 13),	'V'},
> +	{"voldown",	GPIO_NUMBER(4, 5),	'v'},
> +};
> +
> +/*
> + * generate a null-terminated string containing the buttons pressed
> + * returns number of keys pressed
> + */
> +static int read_keys(char *buf)
> +{
> +	int i, numpressed = 0;
> +	for (i = 0; i < ARRAY_SIZE(buttons); i++) {
> +		if (!gpio_get_value(buttons[i].gpnum))
> +			buf[numpressed++] = buttons[i].ident;
> +	}
> +	buf[numpressed] = '\0';
> +	return numpressed;
> +}
> +
> +static int do_kbd(cmd_tbl_t *cmdtp, int flag, int argc, char * const
> argv[]) +{
> +	char envvalue[ARRAY_SIZE(buttons)+1];
> +	int numpressed = read_keys(envvalue);
> +	setenv("keybd", envvalue);
> +	return numpressed == 0;
> +}
> +
> +U_BOOT_CMD(
> +	kbd, 1, 1, do_kbd,
> +	"Tests for keypresses, sets 'keybd' environment variable",
> +	"Returns 0 (true) to shell if key is pressed."
> +);
> +
> +#ifdef CONFIG_PREBOOT
> +static char const kbd_magic_prefix[] = "key_magic";
> +static char const kbd_command_prefix[] = "key_cmd";
> +
> +static void preboot_keys(void)
> +{
> +	int i, numpressed;
> +	char keypress[ARRAY_SIZE(buttons)+1];
> +	numpressed = read_keys(keypress);
> +	if (numpressed) {
> +		char *kbd_magic_keys = getenv("magic_keys");
> +		char *suffix;
> +		/*
> +		 * loop over all magic keys
> +		 */
> +		for (suffix = kbd_magic_keys; *suffix; ++suffix) {
> +			char *keys;
> +			char magic[sizeof(kbd_magic_prefix) + 1];
> +			sprintf(magic, "%s%c", kbd_magic_prefix, *suffix);
> +			keys = getenv(magic);
> +			if (keys) {
> +				if (!strcmp(keys, keypress))
> +					break;
> +			}
> +		}
> +		if (*suffix) {
> +			char cmd_name[sizeof(kbd_command_prefix) + 1];
> +			char *cmd;
> +			sprintf(cmd_name, "%s%c", kbd_command_prefix, *suffix);
> +			cmd = getenv(cmd_name);
> +			if (cmd) {
> +				setenv("preboot", cmd);
> +				return;
> +			}
> +		}
> +	}
> +}
> +#endif
> +
> +int misc_init_r(void)
> +{
> +#ifdef CONFIG_PREBOOT
> +	preboot_keys();
> +#endif
> +}
> diff --git a/include/configs/mx6qsabrelite.h
> b/include/configs/mx6qsabrelite.h index 8bc8a83..7bf8479 100644
> --- a/include/configs/mx6qsabrelite.h
> +++ b/include/configs/mx6qsabrelite.h
> @@ -42,6 +42,7 @@
> 
>  #define CONFIG_ARCH_CPU_INIT
>  #define CONFIG_BOARD_EARLY_INIT_F
> +#define CONFIG_MISC_INIT_R
>  #define CONFIG_MXC_GPIO
> 
>  #define CONFIG_MXC_UART
> @@ -110,6 +111,8 @@
> 
>  #define CONFIG_BOOTDELAY               3
> 
> +#define CONFIG_PREBOOT                 ""
> +
>  #define CONFIG_LOADADDR                        0x10800000
>  #define CONFIG_SYS_TEXT_BASE           0x17800000