From: Russell King Date: Tue, 9 Jul 2013 09:27:12 +0000 (+0100) Subject: ARM: sa11x0: assabet: better reset handling X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7dde0c032869ea92206398ad5c538d01931e3947;p=linux-beck.git ARM: sa11x0: assabet: better reset handling The codec reset pin is connected to several peripherals. When the reset is released, unfortunately the ADV7171 powers itself up rather than remaining in power-down mode. As we don't have a driver for this device, we end up needlessly consuming an additional 330mW. Not only that but we should have a way to arbitrate the reset signal. This patch provides that facility: we program the ADV7171 to sleep mode whenever the reset is released, and we release the reset when any one of the three peripherals requests the reset to be released. Signed-off-by: Russell King --- diff --git a/arch/arm/mach-sa1100/assabet.c b/arch/arm/mach-sa1100/assabet.c index c9808c684152..6a15354d43b8 100644 --- a/arch/arm/mach-sa1100/assabet.c +++ b/arch/arm/mach-sa1100/assabet.c @@ -75,11 +75,142 @@ void ASSABET_BCR_frob(unsigned int mask, unsigned int val) EXPORT_SYMBOL(ASSABET_BCR_frob); +/* + * The codec reset goes to three devices, so we need to release + * the rest when any one of these requests it. However, that + * causes the ADV7171 to consume around 100mA - more than half + * the LCD-blanked power. + * + * With the ADV7171, LCD and backlight enabled, we go over + * budget on the MAX846 Li-Ion charger, and if no Li-Ion battery + * is connected, the Assabet crashes. + */ +#define RST_UCB1X00 (1 << 0) +#define RST_UDA1341 (1 << 1) +#define RST_ADV7171 (1 << 2) + +#define SDA GPIO_GPIO(15) +#define SCK GPIO_GPIO(18) +#define MOD GPIO_GPIO(17) + +static void adv7171_start(void) +{ + GPSR = SCK; + udelay(1); + GPSR = SDA; + udelay(2); + GPCR = SDA; +} + +static void adv7171_stop(void) +{ + GPSR = SCK; + udelay(2); + GPSR = SDA; + udelay(1); +} + +static void adv7171_send(unsigned byte) +{ + unsigned i; + + for (i = 0; i < 8; i++, byte <<= 1) { + GPCR = SCK; + udelay(1); + if (byte & 0x80) + GPSR = SDA; + else + GPCR = SDA; + udelay(1); + GPSR = SCK; + udelay(1); + } + GPCR = SCK; + udelay(1); + GPSR = SDA; + udelay(1); + GPDR &= ~SDA; + GPSR = SCK; + udelay(1); + if (GPLR & SDA) + printk(KERN_WARNING "No ACK from ADV7171\n"); + udelay(1); + GPCR = SCK | SDA; + udelay(1); + GPDR |= SDA; + udelay(1); +} + +static void adv7171_write(unsigned reg, unsigned val) +{ + unsigned gpdr = GPDR; + unsigned gplr = GPLR; + + ASSABET_BCR = BCR_value | ASSABET_BCR_AUDIO_ON; + udelay(100); + + GPCR = SDA | SCK | MOD; /* clear L3 mode to ensure UDA1341 doesn't respond */ + GPDR = (GPDR | SCK | MOD) & ~SDA; + udelay(10); + if (!(GPLR & SDA)) + printk(KERN_WARNING "Something dragging SDA down?\n"); + GPDR |= SDA; + + adv7171_start(); + adv7171_send(0x54); + adv7171_send(reg); + adv7171_send(val); + adv7171_stop(); + + /* Restore GPIO state for L3 bus */ + GPSR = gplr & (SDA | SCK | MOD); + GPCR = (~gplr) & (SDA | SCK | MOD); + GPDR = gpdr; +} + +static void adv7171_sleep(void) +{ + /* Put the ADV7171 into sleep mode */ + adv7171_write(0x04, 0x40); +} + +static unsigned codec_nreset; + +static void assabet_codec_reset(unsigned mask, int set) +{ + unsigned long flags; + bool old; + + local_irq_save(flags); + old = !codec_nreset; + if (set) + codec_nreset &= ~mask; + else + codec_nreset |= mask; + + if (old != !codec_nreset) { + if (codec_nreset) { + ASSABET_BCR_set(ASSABET_BCR_NCODEC_RST); + adv7171_sleep(); + } else { + ASSABET_BCR_clear(ASSABET_BCR_NCODEC_RST); + } + } + local_irq_restore(flags); +} + static void assabet_ucb1x00_reset(enum ucb1x00_reset state) { - if (state == UCB_RST_PROBE) - ASSABET_BCR_set(ASSABET_BCR_CODEC_RST); + int set = state == UCB_RST_REMOVE || state == UCB_RST_SUSPEND || + state == UCB_RST_PROBE_FAIL; + assabet_codec_reset(RST_UCB1X00, set); +} + +void assabet_uda1341_reset(int set) +{ + assabet_codec_reset(RST_UDA1341, set); } +EXPORT_SYMBOL(assabet_uda1341_reset); /* diff --git a/arch/arm/mach-sa1100/include/mach/assabet.h b/arch/arm/mach-sa1100/include/mach/assabet.h index 307391488c22..c23fcdb047a5 100644 --- a/arch/arm/mach-sa1100/include/mach/assabet.h +++ b/arch/arm/mach-sa1100/include/mach/assabet.h @@ -39,8 +39,8 @@ extern unsigned long SCR_value; #define ASSABET_BCR_CF_PWR (1<<0) /* Compact Flash Power (1 = 3.3v, 0 = off) */ #define ASSABET_BCR_CF_RST (1<<1) /* Compact Flash Reset (1 = power up reset) */ -#define ASSABET_BCR_GFX_RST (1<<1) /* Graphics Accelerator Reset (0 = hold reset) */ -#define ASSABET_BCR_CODEC_RST (1<<2) /* 0 = Holds UCB1300, ADI7171, and UDA1341 in reset */ +#define ASSABET_BCR_NGFX_RST (1<<1) /* Graphics Accelerator Reset (0 = hold reset) */ +#define ASSABET_BCR_NCODEC_RST (1<<2) /* 0 = Holds UCB1300, ADI7171, and UDA1341 in reset */ #define ASSABET_BCR_IRDA_FSEL (1<<3) /* IRDA Frequency select (0 = SIR, 1 = MIR/ FIR) */ #define ASSABET_BCR_IRDA_MD0 (1<<4) /* Range/Power select */ #define ASSABET_BCR_IRDA_MD1 (1<<5) /* Range/Power select */ @@ -69,6 +69,8 @@ extern void ASSABET_BCR_frob(unsigned int mask, unsigned int set); #define ASSABET_BCR_frob(x,y) do { } while (0) #endif +extern void assabet_uda1341_reset(int set); + #define ASSABET_BCR_set(x) ASSABET_BCR_frob((x), (x)) #define ASSABET_BCR_clear(x) ASSABET_BCR_frob((x), 0)