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Date: Fri, 12 May 2023 09:52:21 -0500
From: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
To: Charles Keepax <ckeepax@...nsource.cirrus.com>, broonie@...nel.org,
lee@...nel.org, robh+dt@...nel.org,
krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
tglx@...utronix.de, maz@...nel.org, linus.walleij@...aro.org,
vkoul@...nel.org
Cc: lgirdwood@...il.com, yung-chuan.liao@...ux.intel.com,
sanyog.r.kale@...el.com, alsa-devel@...a-project.org,
patches@...nsource.cirrus.com, devicetree@...r.kernel.org,
linux-gpio@...r.kernel.org, linux-spi@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH 06/10] mfd: cs42l43: Add support for cs42l43 core driver
> +static int cs42l43_sdw_update_status(struct sdw_slave *sdw, enum sdw_slave_status status)
> +{
> + struct cs42l43 *cs42l43 = dev_get_drvdata(&sdw->dev);
> +
> + switch (status) {
> + case SDW_SLAVE_ATTACHED:
> + dev_dbg(cs42l43->dev, "Device attach\n");
> +
> + sdw_write_no_pm(sdw, CS42L43_GEN_INT_MASK_1,
> + CS42L43_INT_STAT_GEN1_MASK);
> +
> + cs42l43->attached = true;
> +
> + complete(&cs42l43->device_attach);
> + break;
> + case SDW_SLAVE_UNATTACHED:
> + dev_dbg(cs42l43->dev, "Device detach\n");
> +
> + cs42l43->attached = false;
> +
> + reinit_completion(&cs42l43->device_attach);
> + complete(&cs42l43->device_detach);
> + break;
> + default:
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static int cs42l43_sdw_interrupt(struct sdw_slave *sdw,
> + struct sdw_slave_intr_status *status)
> +{
> + /*
> + * There is only a single bit in GEN_INT_STAT_1 and it doesn't clear if
> + * IRQs are still pending so doing a read/write here after handling the
> + * IRQ is fine.
> + */
> + sdw_read_no_pm(sdw, CS42L43_GEN_INT_STAT_1);
> + sdw_write_no_pm(sdw, CS42L43_GEN_INT_STAT_1, 1);
> +
> + return 0;
> +}
not really getting the comment and code above. Where is the IRQ handled?
In the 'other non-SoundWire part"?
> +static void cs42l43_boot_work(struct work_struct *work)
> +{
> + struct cs42l43 *cs42l43 = container_of(work, struct cs42l43, boot_work);
> + unsigned int devid, revid, otp;
> + int ret;
> +
> + dev_dbg(cs42l43->dev, "Boot work running\n");
> +
> + ret = cs42l43_wait_for_attach(cs42l43);
> + if (ret)
> + goto err;
> +
> + if (cs42l43->sdw)
> + cs42l43->irq = cs42l43->sdw->irq;
> +
> + ret = regmap_read(cs42l43->regmap, CS42L43_DEVID, &devid);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to read devid: %d\n", ret);
> + goto err;
> + }
> +
> + switch (devid) {
> + case 0x42a43:
> + break;
> + default:
> + dev_err(cs42l43->dev, "Unrecognised devid: 0x%06x\n", devid);
> + goto err;
> + }
> +
> + ret = regmap_read(cs42l43->regmap, CS42L43_REVID, &revid);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to read rev: %d\n", ret);
> + goto err;
> + }
> +
> + ret = regmap_read(cs42l43->regmap, CS42L43_OTP_REVISION_ID, &otp);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to read otp rev: %d\n", ret);
> + goto err;
> + }
> +
> + dev_info(cs42l43->dev,
> + "devid: 0x%06x, rev: 0x%02x, otp: 0x%02x\n", devid, revid, otp);
> +
> + ret = cs42l43_mcu_update(cs42l43);
> + if (ret)
> + goto err;
> +
> + ret = regmap_register_patch(cs42l43->regmap, cs42l43_reva_patch,
> + ARRAY_SIZE(cs42l43_reva_patch));
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to apply register patch: %d\n", ret);
> + goto err;
> + }
> +
> + pm_runtime_mark_last_busy(cs42l43->dev);
> + pm_runtime_put_autosuspend(cs42l43->dev);
any reason why the two pm_runtime routines are not placed last, just
before the return?
> + ret = devm_mfd_add_devices(cs42l43->dev, PLATFORM_DEVID_NONE,
> + cs42l43_devs, ARRAY_SIZE(cs42l43_devs),
> + NULL, 0, NULL);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to add subdevices: %d\n", ret);
> + goto err;
> + }
> +
> + dev_dbg(cs42l43->dev, "Successfully initialised\n");
> +
> + return;
> +
> +err:
> + pm_runtime_put_sync(cs42l43->dev);
> + cs42l43_dev_remove(cs42l43);
> +}
> +int cs42l43_dev_probe(struct cs42l43 *cs42l43)
> +{
> + int i, ret;
> +
> + dev_set_drvdata(cs42l43->dev, cs42l43);
> +
> + mutex_init(&cs42l43->pll_lock);
> + init_completion(&cs42l43->device_attach);
> + init_completion(&cs42l43->device_detach);
> + init_completion(&cs42l43->firmware_download);
> + INIT_WORK(&cs42l43->boot_work, cs42l43_boot_work);
> +
> + regcache_cache_only(cs42l43->regmap, true);
> +
> + cs42l43->reset = devm_gpiod_get_optional(cs42l43->dev, "reset", GPIOD_OUT_LOW);
> + if (IS_ERR(cs42l43->reset)) {
> + ret = PTR_ERR(cs42l43->reset);
> + dev_err(cs42l43->dev, "Failed to get reset: %d\n", ret);
> + return ret;
> + }
> +
> + cs42l43->vdd_p = devm_regulator_get(cs42l43->dev, "VDD_P");
> + if (IS_ERR(cs42l43->vdd_p)) {
> + ret = PTR_ERR(cs42l43->vdd_p);
> + dev_err(cs42l43->dev, "Failed to get VDD_P: %d\n", ret);
> + return ret;
> + }
> +
> + cs42l43->vdd_d = devm_regulator_get(cs42l43->dev, "VDD_D");
> + if (IS_ERR(cs42l43->vdd_d)) {
> + ret = PTR_ERR(cs42l43->vdd_d);
> + dev_err(cs42l43->dev, "Failed to get VDD_D: %d\n", ret);
> + return ret;
> + }
> +
> + BUILD_BUG_ON(ARRAY_SIZE(cs42l43_core_supplies) != CS42L43_N_SUPPLIES);
> +
> + for (i = 0; i < CS42L43_N_SUPPLIES; i++)
> + cs42l43->core_supplies[i].supply = cs42l43_core_supplies[i];
> +
> + ret = devm_regulator_bulk_get(cs42l43->dev, CS42L43_N_SUPPLIES,
> + cs42l43->core_supplies);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to get core supplies: %d\n", ret);
> + return ret;
> + }
> +
> + ret = cs42l43_power_up(cs42l43);
> + if (ret)
> + return ret;
> +
> + pm_runtime_set_autosuspend_delay(cs42l43->dev, 250);
> + pm_runtime_use_autosuspend(cs42l43->dev);
> + pm_runtime_set_active(cs42l43->dev);> + pm_runtime_get_noresume(cs42l43->dev);
you probably want a comment to explain that the get_noresume() is
intentional to prevent the device from suspending before the workqueue
is handled.
> + pm_runtime_enable(cs42l43->dev);
> +
> + queue_work(system_long_wq, &cs42l43->boot_work);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_NS_GPL(cs42l43_dev_probe, MFD_CS42L43);
> +static int __maybe_unused cs42l43_suspend(struct device *dev)
> +{
> + struct cs42l43 *cs42l43 = dev_get_drvdata(dev);
> + int ret;
> +
> + dev_dbg(cs42l43->dev, "System suspend\n");
> +
> + /*
> + * Don't care about being resumed here, but we do want force_resume to
> + * always trigger an actual resume, so that register state for the
> + * MCU/GPIOs is returned as soon as possible after system resume
> + */
> + pm_runtime_get_noresume(dev);
> +
> + ret = pm_runtime_force_suspend(dev);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to force suspend: %d\n", ret);
> + return ret;
> + }
> +
> + pm_runtime_put_noidle(dev);
Is the get_noresume/put_noidle useful here? What does it do?
And it seems wrong anyways, if pm_runtime_force_suspend() fails then the
usage-count is not decreased.
Surprising sequence...
> +
> + ret = cs42l43_power_down(cs42l43);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int __maybe_unused cs42l43_resume(struct device *dev)
> +{
> + struct cs42l43 *cs42l43 = dev_get_drvdata(dev);
> + int ret;
> +
> + dev_dbg(cs42l43->dev, "System resume\n");
> +
> + ret = cs42l43_power_up(cs42l43);
> + if (ret)
> + return ret;
> +
> + ret = pm_runtime_force_resume(dev);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to force resume: %d\n", ret);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int __maybe_unused cs42l43_runtime_suspend(struct device *dev)
> +{
> + struct cs42l43 *cs42l43 = dev_get_drvdata(dev);
> +
> + dev_dbg(cs42l43->dev, "Runtime suspend\n");
> +
> + /*
> + * Whilst we don't power the chip down here, going into runtime
> + * suspend lets the SoundWire bus power down, which means we can't
> + * communicate with the device any more.
> + */
> + regcache_cache_only(cs42l43->regmap, true);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused cs42l43_runtime_resume(struct device *dev)
> +{
> + struct cs42l43 *cs42l43 = dev_get_drvdata(dev);
> + unsigned int reset_canary;
> + int ret;
> +
> + dev_dbg(cs42l43->dev, "Runtime resume\n");
> +
> + ret = cs42l43_wait_for_attach(cs42l43);
is there a specific reason why the existing initialization_complete is
not used?
> + if (ret)
> + return ret;
> +
> + ret = regmap_read(cs42l43->regmap, CS42L43_RELID, &reset_canary);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to check reset canary: %d\n", ret);
> + goto err;
> + }
> +
> + if (!reset_canary) {
> + /*
> + * If the canary has cleared the chip has reset, re-handle the
> + * MCU and mark the cache as dirty to indicate the chip reset.
> + */
> + ret = cs42l43_mcu_update(cs42l43);
> + if (ret)
> + goto err;
> +
> + regcache_mark_dirty(cs42l43->regmap);
> + }
> +
> + ret = regcache_sync(cs42l43->regmap);
> + if (ret) {
> + dev_err(cs42l43->dev, "Failed to restore register cache: %d\n", ret);
> + goto err;
> + }
> +
> + return 0;
> +
> +err:
> + regcache_cache_only(cs42l43->regmap, true);
> +
> + return ret;
> +}
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