diff options
| author |   Maciej S. Szmigiero <mail@maciej.szmigiero.name> | 2017-11-20 23:16:07 +0100 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2017-11-27 16:43:43 +0000 |
| commit | b880b8056b31288323745a13930bc45cf4c86e9d (patch) | |
| tree | f249f5077bd7d905f0d837a7916a499d8fe38def /sound | |
| parent | ASoC: fsl_ssi: AC'97 ops need regmap, clock and cleaning up on failure (diff) | |
| download | linux-dev-b880b8056b31288323745a13930bc45cf4c86e9d.tar.xz linux-dev-b880b8056b31288323745a13930bc45cf4c86e9d.zip | |
ASoC: fsl_ssi: serialize AC'97 register access operations
AC'97 register access operations (both read and write) on SSI use a one,
shared set of SSI registers for AC'97 register address and data.
This means that only one such access is possible at a time and so all these
operations need to be serialized.
Since an AC'97 register access operation in this driver takes 100us+ let's
use a mutex for this.
Use this opportunity to also change a default value returned from AC'97
register read function from -1 to 0, since that's what AC'97 specs require
to be returned when unknown / undefined registers are read.
Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/soc/fsl/fsl_ssi.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c index c3a83ed0297e..424bafaf51ef 100644 --- a/sound/soc/fsl/fsl_ssi.c +++ b/sound/soc/fsl/fsl_ssi.c @@ -38,6 +38,7 @@ #include <linux/ctype.h> #include <linux/device.h> #include <linux/delay.h> +#include <linux/mutex.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/of.h> @@ -265,6 +266,8 @@ struct fsl_ssi_private { u32 fifo_watermark; u32 dma_maxburst; + + struct mutex ac97_reg_lock; }; /* @@ -1260,11 +1263,13 @@ static void fsl_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg, if (reg > 0x7f) return; + mutex_lock(&fsl_ac97_data->ac97_reg_lock); + ret = clk_prepare_enable(fsl_ac97_data->clk); if (ret) { pr_err("ac97 write clk_prepare_enable failed: %d\n", ret); - return; + goto ret_unlock; } lreg = reg << 12; @@ -1278,6 +1283,9 @@ static void fsl_ssi_ac97_write(struct snd_ac97 *ac97, unsigned short reg, udelay(100); clk_disable_unprepare(fsl_ac97_data->clk); + +ret_unlock: + mutex_unlock(&fsl_ac97_data->ac97_reg_lock); } static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97, @@ -1285,16 +1293,18 @@ static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97, { struct regmap *regs = fsl_ac97_data->regs; - unsigned short val = -1; + unsigned short val = 0; u32 reg_val; unsigned int lreg; int ret; + mutex_lock(&fsl_ac97_data->ac97_reg_lock); + ret = clk_prepare_enable(fsl_ac97_data->clk); if (ret) { pr_err("ac97 read clk_prepare_enable failed: %d\n", ret); - return -1; + goto ret_unlock; } lreg = (reg & 0x7f) << 12; @@ -1309,6 +1319,8 @@ static unsigned short fsl_ssi_ac97_read(struct snd_ac97 *ac97, clk_disable_unprepare(fsl_ac97_data->clk); +ret_unlock: + mutex_unlock(&fsl_ac97_data->ac97_reg_lock); return val; } @@ -1569,6 +1581,7 @@ static int fsl_ssi_probe(struct platform_device *pdev) } if (fsl_ssi_is_ac97(ssi_private)) { + mutex_init(&ssi_private->ac97_reg_lock); ret = snd_soc_set_ac97_ops_of_reset(&fsl_ssi_ac97_ops, pdev); if (ret) { dev_err(&pdev->dev, "could not set AC'97 ops\n"); @@ -1663,6 +1676,9 @@ error_asoc_register: snd_soc_set_ac97_ops(NULL); error_ac97_ops: + if (fsl_ssi_is_ac97(ssi_private)) + mutex_destroy(&ssi_private->ac97_reg_lock); + if (ssi_private->soc->imx) fsl_ssi_imx_clean(pdev, ssi_private); @@ -1681,8 +1697,10 @@ static int fsl_ssi_remove(struct platform_device *pdev) if (ssi_private->soc->imx) fsl_ssi_imx_clean(pdev, ssi_private); - if (fsl_ssi_is_ac97(ssi_private)) + if (fsl_ssi_is_ac97(ssi_private)) { snd_soc_set_ac97_ops(NULL); + mutex_destroy(&ssi_private->ac97_reg_lock); + } return 0; } |