From 41b645c8624df6ace020a8863ad1449d69140f7d Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Mon, 7 Jan 2013 13:55:12 -0800 Subject: ALSA: pxa27x: fix ac97 cold reset Cold reset on the pxa27x currently fails and pxa2xx_ac97_try_cold_reset: cold reset timeout (GSR=0x44) appears in the kernel log. Through trial-and-error (the pxa270 developer's manual is mostly incoherent on the topic of ac97 reset), I got cold reset to complete by setting the WARM_RST bit in the GCR register (and later noticed that pxa3xx does this for cold reset as well). Also, a timeout loop is needed to wait for the reset to complete. Tested on a palm treo 680 machine. Signed-off-by: Mike Dunn Acked-by: Igor Grinberg Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- sound/arm/pxa2xx-ac97-lib.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'sound') diff --git a/sound/arm/pxa2xx-ac97-lib.c b/sound/arm/pxa2xx-ac97-lib.c index 6fc0ae90e5b1..1ecd0a66ecd3 100644 --- a/sound/arm/pxa2xx-ac97-lib.c +++ b/sound/arm/pxa2xx-ac97-lib.c @@ -148,6 +148,8 @@ static inline void pxa_ac97_warm_pxa27x(void) static inline void pxa_ac97_cold_pxa27x(void) { + unsigned int timeout; + GCR &= GCR_COLD_RST; /* clear everything but nCRST */ GCR &= ~GCR_COLD_RST; /* then assert nCRST */ @@ -157,8 +159,10 @@ static inline void pxa_ac97_cold_pxa27x(void) clk_enable(ac97conf_clk); udelay(5); clk_disable(ac97conf_clk); - GCR = GCR_COLD_RST; - udelay(50); + GCR = GCR_COLD_RST | GCR_WARM_RST; + timeout = 100; /* wait for the codec-ready bit to be set */ + while (!((GSR | gsr_bits) & (GSR_PCR | GSR_SCR)) && timeout--) + mdelay(1); } #endif -- cgit v1.2.3-59-g8ed1b From 3b4bc7bccc7857274705b05cf81a0c72cfd0b0dd Mon Sep 17 00:00:00 2001 From: Mike Dunn Date: Mon, 7 Jan 2013 13:55:13 -0800 Subject: ALSA: pxa27x: fix ac97 warm reset This patch fixes some code that implements a work-around to a hardware bug in the ac97 controller on the pxa27x. A bug in the controller's warm reset functionality requires that the mfp used by the controller as the AC97_nRESET line be temporarily reconfigured as a generic output gpio (AF0) and manually held high for the duration of the warm reset cycle. This is what was done in the original code, but it was broken long ago by commit fb1bf8cd ([ARM] pxa: introduce processor specific pxa27x_assert_ac97reset()) which changed the mfp to a GPIO input instead of a high output. The fix requires the ac97 controller to obtain the gpio via gpio_request_one(), with arguments that configure the gpio as an output initially driven high. Tested on a palm treo 680 machine. Reportedly, this broken code only prevents a warm reset on hardware that lacks a pull-up on the line, which appears to be the case for me. Signed-off-by: Mike Dunn Signed-off-by: Igor Grinberg Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- arch/arm/mach-pxa/include/mach/mfp-pxa27x.h | 3 +++ arch/arm/mach-pxa/pxa27x.c | 4 ++-- sound/arm/pxa2xx-ac97-lib.c | 18 +++++++++++++++++- 3 files changed, 22 insertions(+), 3 deletions(-) (limited to 'sound') diff --git a/arch/arm/mach-pxa/include/mach/mfp-pxa27x.h b/arch/arm/mach-pxa/include/mach/mfp-pxa27x.h index a611ad3153c7..b6132aa95dc0 100644 --- a/arch/arm/mach-pxa/include/mach/mfp-pxa27x.h +++ b/arch/arm/mach-pxa/include/mach/mfp-pxa27x.h @@ -463,6 +463,9 @@ GPIO76_LCD_PCLK, \ GPIO77_LCD_BIAS +/* these enable a work-around for a hw bug in pxa27x during ac97 warm reset */ +#define GPIO113_AC97_nRESET_GPIO_HIGH MFP_CFG_OUT(GPIO113, AF0, DEFAULT) +#define GPIO95_AC97_nRESET_GPIO_HIGH MFP_CFG_OUT(GPIO95, AF0, DEFAULT) extern int keypad_set_wake(unsigned int on); #endif /* __ASM_ARCH_MFP_PXA27X_H */ diff --git a/arch/arm/mach-pxa/pxa27x.c b/arch/arm/mach-pxa/pxa27x.c index 8047ee0effc5..616cb87b6179 100644 --- a/arch/arm/mach-pxa/pxa27x.c +++ b/arch/arm/mach-pxa/pxa27x.c @@ -47,9 +47,9 @@ void pxa27x_clear_otgph(void) EXPORT_SYMBOL(pxa27x_clear_otgph); static unsigned long ac97_reset_config[] = { - GPIO113_GPIO, + GPIO113_AC97_nRESET_GPIO_HIGH, GPIO113_AC97_nRESET, - GPIO95_GPIO, + GPIO95_AC97_nRESET_GPIO_HIGH, GPIO95_AC97_nRESET, }; diff --git a/sound/arm/pxa2xx-ac97-lib.c b/sound/arm/pxa2xx-ac97-lib.c index 1ecd0a66ecd3..fff7753e35c1 100644 --- a/sound/arm/pxa2xx-ac97-lib.c +++ b/sound/arm/pxa2xx-ac97-lib.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -344,8 +345,21 @@ int pxa2xx_ac97_hw_probe(struct platform_device *dev) } if (cpu_is_pxa27x()) { - /* Use GPIO 113 as AC97 Reset on Bulverde */ + /* + * This gpio is needed for a work-around to a bug in the ac97 + * controller during warm reset. The direction and level is set + * here so that it is an output driven high when switching from + * AC97_nRESET alt function to generic gpio. + */ + ret = gpio_request_one(reset_gpio, GPIOF_OUT_INIT_HIGH, + "pxa27x ac97 reset"); + if (ret < 0) { + pr_err("%s: gpio_request_one() failed: %d\n", + __func__, ret); + goto err_conf; + } pxa27x_assert_ac97reset(reset_gpio, 0); + ac97conf_clk = clk_get(&dev->dev, "AC97CONFCLK"); if (IS_ERR(ac97conf_clk)) { ret = PTR_ERR(ac97conf_clk); @@ -388,6 +402,8 @@ EXPORT_SYMBOL_GPL(pxa2xx_ac97_hw_probe); void pxa2xx_ac97_hw_remove(struct platform_device *dev) { + if (cpu_is_pxa27x()) + gpio_free(reset_gpio); GCR |= GCR_ACLINK_OFF; free_irq(IRQ_AC97, NULL); if (ac97conf_clk) { -- cgit v1.2.3-59-g8ed1b