diff options
| author | Richard Fitzgerald <rf@opensource.cirrus.com> | 2025-02-25 13:18:43 +0000 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2025-02-25 15:06:58 +0000 |
| commit | 769c1b79295c38d60fde4c0a8f5f31e01360c54f (patch) | |
| tree | 005af6992f9517058621037c96f369a6bfd1b5da /include/sound | |
| parent | fe08b7d5085a9774abc30c26d5aebc5b9cdd6091 (diff) | |
| download | linux-769c1b79295c38d60fde4c0a8f5f31e01360c54f.tar.gz | |
ASoC: cs35l56: Prevent races when soft-resetting using SPI control
When SPI is used for control, the driver must hold the SPI bus lock
while issuing the sequence of writes to perform a soft reset.
>From the time the driver writes the SYSTEM_RESET command until the
driver does a write to terminate the reset, there must not be any
activity on the SPI bus lines. If there is any SPI activity during the
soft-reset, another soft-reset will be triggered. The state of the SPI
chip select is irrelevant.
A repeated soft-reset does not in itself cause any problems, and it is
not an infinite loop. The problem is a race between these resets and
the driver polling for boot completion. There is a time window between
soft resets where the driver could read HALO_STATE as 2 (fully booted)
while the chip is actually soft-resetting. Although this window is
small, it is long enough that it is possible to hit it in normal
operation.
To prevent this race and ensure the chip really is fully booted, the
driver calls spi_bus_lock() to prevent other activity while resetting.
It then issues the SYSTEM_RESET mailbox command. After allowing
sufficient time for reset to take effect, the driver issues a PING
mailbox command, which will force completion of the full soft-reset
sequence. The SPI bus lock can then be released. The mailbox is
checked for any boot or wakeup response from the firmware, before the
value in HALO_STATE will be trusted.
This does not affect SoundWire or I2C control.
Fixes: 8a731fd37f8b ("ASoC: cs35l56: Move utility functions to shared file")
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20250225131843.113752-3-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'include/sound')
| -rw-r--r-- | include/sound/cs35l56.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/include/sound/cs35l56.h b/include/sound/cs35l56.h index 3dc7a1551ac350..5d653a3491d073 100644 --- a/include/sound/cs35l56.h +++ b/include/sound/cs35l56.h @@ -12,6 +12,7 @@ #include <linux/firmware/cirrus/cs_dsp.h> #include <linux/regulator/consumer.h> #include <linux/regmap.h> +#include <linux/spi/spi.h> #include <sound/cs-amp-lib.h> #define CS35L56_DEVID 0x0000000 @@ -61,6 +62,7 @@ #define CS35L56_IRQ1_MASK_8 0x000E0AC #define CS35L56_IRQ1_MASK_18 0x000E0D4 #define CS35L56_IRQ1_MASK_20 0x000E0DC +#define CS35L56_DSP_MBOX_1_RAW 0x0011000 #define CS35L56_DSP_VIRTUAL1_MBOX_1 0x0011020 #define CS35L56_DSP_VIRTUAL1_MBOX_2 0x0011024 #define CS35L56_DSP_VIRTUAL1_MBOX_3 0x0011028 @@ -224,6 +226,7 @@ #define CS35L56_HALO_STATE_SHUTDOWN 1 #define CS35L56_HALO_STATE_BOOT_DONE 2 +#define CS35L56_MBOX_CMD_PING 0x0A000000 #define CS35L56_MBOX_CMD_AUDIO_PLAY 0x0B000001 #define CS35L56_MBOX_CMD_AUDIO_PAUSE 0x0B000002 #define CS35L56_MBOX_CMD_AUDIO_REINIT 0x0B000003 @@ -254,6 +257,16 @@ #define CS35L56_NUM_BULK_SUPPLIES 3 #define CS35L56_NUM_DSP_REGIONS 5 +/* Additional margin for SYSTEM_RESET to control port ready on SPI */ +#define CS35L56_SPI_RESET_TO_PORT_READY_US (CS35L56_CONTROL_PORT_READY_US + 2500) + +struct cs35l56_spi_payload { + __be32 addr; + __be16 pad; + __be32 value; +} __packed; +static_assert(sizeof(struct cs35l56_spi_payload) == 10); + struct cs35l56_base { struct device *dev; struct regmap *regmap; @@ -269,6 +282,7 @@ struct cs35l56_base { s8 cal_index; struct cirrus_amp_cal_data cal_data; struct gpio_desc *reset_gpio; + struct cs35l56_spi_payload *spi_payload_buf; }; static inline bool cs35l56_is_otp_register(unsigned int reg) @@ -276,6 +290,23 @@ static inline bool cs35l56_is_otp_register(unsigned int reg) return (reg >> 16) == 3; } +static inline int cs35l56_init_config_for_spi(struct cs35l56_base *cs35l56, + struct spi_device *spi) +{ + cs35l56->spi_payload_buf = devm_kzalloc(&spi->dev, + sizeof(*cs35l56->spi_payload_buf), + GFP_KERNEL | GFP_DMA); + if (!cs35l56->spi_payload_buf) + return -ENOMEM; + + return 0; +} + +static inline bool cs35l56_is_spi(struct cs35l56_base *cs35l56) +{ + return IS_ENABLED(CONFIG_SPI_MASTER) && !!cs35l56->spi_payload_buf; +} + extern const struct regmap_config cs35l56_regmap_i2c; extern const struct regmap_config cs35l56_regmap_spi; extern const struct regmap_config cs35l56_regmap_sdw; |