kernel/git/stable/linux.git/sound/soc/codecs/cs42l42.h, branch master

ASoC: cs42l42: Drop legacy include

2023-12-01T16:59:23+00:00

This driver includes the legacy GPIO API but does not use any symbols from it. Drop the include. Acked-by: Charles Keepax Signed-off-by: Linus Walleij Link: https://lore.kernel.org/r/20231201-descriptors-sound-cirrus-v2-8-ee9f9d4655eb@linaro.org Signed-off-by: Mark Brown

ASoC: cs42l42: Avoid stale SoundWire ATTACH after hard reset

2023-09-13T15:03:21+00:00

In SoundWire mode leave hard RESET asserted when exiting probe, and wait for an UNATTACHED notification before deasserting RESET. If the boot state of the reset GPIO was deasserted it is possible that the SoundWire core had already enumerated the CS42L42 before cs42l42_sdw_probe() is called. When cs42l42_common_probe() hard resets the CS42L42 it triggers a race condition: 1) After cs42l42_sdw_probe() returns the thread that called it will call cs42l42_sdw_update_status() to report the last status recorded by the SoundWire core. 2) The SoundWire bus master will see a PING with the CS42L42 now reporting as unenumerated and will trigger the core SoundWire code to start enumerating CS42L42. These two threads are racing against each other. If (1) happens before (2) a stale ATTACHED notification will be reported to the cs42l42 driver when in fact the status of cs42l42 is now unattached. To avoid this race condition: - Leave RESET asserted on exit from cs42l42_sdw_probe(). This ensures that an UNATTACHED notification must be sent to the cs42l42 driver. If cs42l42 was already enumerated it will be seen to drop off the bus, causing an UNATTACH notification. If it was never enumerated the status is already UNATTACHED and this will be reported by thread (1). - When the UNATTACH notification is received, release RESET. This will cause CS42L42 to be enumerated and eventually report an ATTACHED notification. - The ATTACHED notification is now valid. Signed-off-by: Richard Fitzgerald Signed-off-by: Stefan Binding Link: https://lore.kernel.org/r/20230913150012.604775-4-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown

ASoC: cs42l42: Add SoundWire support

2023-01-31T12:10:50+00:00

This adds support for using CS42L42 as a SoundWire device. SoundWire-specifics are kept separate from the I2S implementation as much as possible, aiming to limit the risk of breaking the I2C+I2S support. There are some important differences in the silicon behaviour between I2S and SoundWire mode that are reflected in the implementation: - ASP (I2S) most not be used in SoundWire mode because the two interfaces share pins. - The SoundWire capture (record) port only supports 1 channel. It does not have left-to-right duplication like the ASP. - DP2 can only be prepared if the HP has powered-up. DP1 can only be prepared if the ADC has powered-up. (This ordering restriction does not exist for ASPs.) The SoundWire core port-prepare step is triggered by the DAI-link prepare(). This happens before the codec DAI prepare() or the DAPM sequence so these cannot be used to enable HP/ADC. Instead the HP/ADC enable/disable are done during the port_prep callback. - The SRCs are an integral part of the audio chain but in silicon their power control is linked to the ASP. There is no equivalent power link to SoundWire DPs so the driver must take "manual" control of SRC power. - The SoundWire control registers occupy the lower part of the SoundWire address space so cs42l42 registers are offset by 0x8000 (non-paged) in SoundWire mode. - Register addresses are 8-bit paged in I2C mode but 16-bit unpaged in SoundWire. - Special procedures are needed on register read/writes to (a) ensure that the previous internal bus transaction has completed, and (b) handle delayed read results, when the read value could not be returned within the SoundWire read command. There are also some differences in driver implementation between I2S and SoundWire operation: - CS42L42 I2S does not runtime_suspend, but runtime_suspend/resume support has been added into the driver in SoundWire mode as the most convenient way to power-up the bus manager and to handle the unattach_request condition, though the CS42L42 chip does not itself suspend or resume. - Intel SoundWire host controllers have a low-power clock-stop mode that requires resetting all peripherals when resuming. This means that the interrupt registers will be reset in between the interrupt being generated and the interrupt being handled, and since the interrupt status is debounced, these values may not be accurate immediately, and may cause spurious unplug events before settling. - As in I2S mode, the PLL is only used while audio is active because of clocking quirks in the silicon. For SoundWire the cs42l42_pll_config() is deferred until the DAI prepare(), to allow the cs42l42_bus_config() callback to set the SCLK. Signed-off-by: Richard Fitzgerald Signed-off-by: Stefan Binding Reviewed-by: Pierre-Louis Bossart Link: https://lore.kernel.org/r/20230127165111.3010960-7-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown

ASoC: cs42l42: Export some functions for SoundWire

2023-01-31T12:10:49+00:00

Export functions that will be needed by a SoundWire module. Signed-off-by: Richard Fitzgerald Signed-off-by: Stefan Binding Reviewed-by: Pierre-Louis Bossart Link: https://lore.kernel.org/r/20230127165111.3010960-6-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown

ASoC: cs42l42: Separate ASP config from PLL config

2023-01-31T12:10:48+00:00

Setup of the ASP (audio serial port) was being done as a side-effect of cs42l42_pll_config() and forces a restriction on the ratio of sample_rate to bit_clock that is invalid for Soundwire. Move the ASP setup into a dedicated function. Signed-off-by: Richard Fitzgerald Signed-off-by: Stefan Binding Reviewed-by: Pierre-Louis Bossart Link: https://lore.kernel.org/r/20230127165111.3010960-5-sbinding@opensource.cirrus.com Signed-off-by: Mark Brown

ASoC: cs42l42: Implement 'set_bclk_ratio'

2022-09-19T17:05:36+00:00

The driver wants to know the bit rate on the serial bus and takes that to be the value set by 'set_sysclk'. The 'set_bclk_ratio' op is a better fit for figuring out the clocking parameters of the serial bus, so implement that and give it precedence over the prior methods. Signed-off-by: Martin Povišer Link: https://lore.kernel.org/r/20220915094444.11434-11-povik+lin@cutebit.org Signed-off-by: Mark Brown

ASoC: cs42l83: Extend CS42L42 support to new part

2022-09-19T17:05:35+00:00

The CS42L83 part is a headphone jack codec found in recent Apple machines. It is a publicly undocumented part but as far as can be told it is identical to CS42L42 except for two points: * The chip ID is different. * Of those registers for which we have a default value in the existing CS42L42 kernel driver, one register (MCLK_CTL) differs in its reset value on CS42L83. To address those two points (and only those), add to the CS42L42 driver a separate CS42L83 front. Signed-off-by: Martin Povišer Link: https://lore.kernel.org/r/20220915094444.11434-10-povik+lin@cutebit.org Signed-off-by: Mark Brown

ASoC: cs42l42: Export regmap elements to core namespace

2022-09-19T17:05:34+00:00

Export the regmap callbacks for indicating readable/volatile registers, also the range structure, to the CS42L42 core namespace. This is in advance of reusing these bits in a CS42L83 driver frontend. Signed-off-by: Martin Povišer Link: https://lore.kernel.org/r/20220915094444.11434-9-povik+lin@cutebit.org Signed-off-by: Mark Brown

ASoC: cs42l42: Split I2C identity into separate module

2022-09-19T17:05:33+00:00

Split the I2C bus driver definition and probe()/remove() into a separate module so that a SoundWire build of CS42L42 support does not have a spurious dependency on I2C. Signed-off-by: Richard Fitzgerald Signed-off-by: Martin Povišer Link: https://lore.kernel.org/r/20220915094444.11434-8-povik+lin@cutebit.org Signed-off-by: Mark Brown

ASoC: cs42l42: Split probe() and remove() into stages

2022-09-19T17:05:30+00:00

To prepare for adding SoundWire the probe must be split into three parts: 1) The bus-specific probe 2) Common bus-agnostic probe steps 3) Initialization of the peripheral registers Step (3) must be separate because on SoundWire devices the probe must enable power supplies and release reset so that the peripheral can be enumerated by the bus, but it isn't possible to access registers until enumeration has completed. The call to devm_snd_soc_register_component() must be done at stage (2) so that it can EPROBE_DEFER if necessary. In SoundWire systems stage (3) is not a probe event so a deferral at this stage would not result in re-probing dependencies. A new init_done flag indicates that the chip has been identified and initialized. This is used to prevent cs42l42_remove(), cs42l42_suspend(), cs42l42_restore() and cs42l42_irq_thread() from attempting register accesses if the chip was not successfully initialized. Although this cannot happen on I2C, because the entire probe would fail, it is possible on SoundWire if probe succeeds but the cs42l42 is never enumerated. Signed-off-by: Richard Fitzgerald Signed-off-by: Martin Povišer Link: https://lore.kernel.org/r/20220915094444.11434-5-povik+lin@cutebit.org Signed-off-by: Mark Brown