mfd: madera: Add common support for Cirrus Logic Madera codecs

This adds the generic core support for Cirrus Logic "Madera" class codecs.
These are complex audio codec SoCs with a variety of digital and analogue
I/O, onboard audio processing and DSPs, and other features.

These codecs are all based off a common set of hardware IP so can be
supported by a core of common code (with a few minor device-to-device
variations).

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Nikesh Oswal <Nikesh.Oswal@cirrus.com>
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

1 files changed, 609 insertions, 0 deletions

diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c
new file mode 100644
index 000000000000..8cfea969b060
--- /dev/null
+++ b/drivers/mfd/madera-core.c
@@ -0,0 +1,609 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Core MFD support for Cirrus Logic Madera codecs
+ *
+ * Copyright (C) 2015-2018 Cirrus Logic
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; version 2.
+ */
+
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+
+#include <linux/mfd/madera/core.h>
+#include <linux/mfd/madera/registers.h>
+
+#include "madera.h"
+
+#define CS47L35_SILICON_ID	0x6360
+#define CS47L85_SILICON_ID	0x6338
+#define CS47L90_SILICON_ID	0x6364
+
+#define MADERA_32KZ_MCLK2	1
+
+static const char * const madera_core_supplies[] = {
+	"AVDD",
+	"DBVDD1",
+};
+
+static const struct mfd_cell madera_ldo1_devs[] = {
+	{ .name = "madera-ldo1" },
+};
+
+static const char * const cs47l35_supplies[] = {
+	"MICVDD",
+	"DBVDD2",
+	"CPVDD1",
+	"CPVDD2",
+	"SPKVDD",
+};
+
+static const struct mfd_cell cs47l35_devs[] = {
+	{ .name = "madera-pinctrl", },
+	{ .name = "madera-irq", },
+	{ .name = "madera-micsupp", },
+	{ .name = "madera-gpio", },
+	{ .name = "madera-extcon", },
+	{
+		.name = "cs47l35-codec",
+		.parent_supplies = cs47l35_supplies,
+		.num_parent_supplies = ARRAY_SIZE(cs47l35_supplies),
+	},
+};
+
+static const char * const cs47l85_supplies[] = {
+	"MICVDD",
+	"DBVDD2",
+	"DBVDD3",
+	"DBVDD4",
+	"CPVDD1",
+	"CPVDD2",
+	"SPKVDDL",
+	"SPKVDDR",
+};
+
+static const struct mfd_cell cs47l85_devs[] = {
+	{ .name = "madera-pinctrl", },
+	{ .name = "madera-irq", },
+	{ .name = "madera-micsupp" },
+	{ .name = "madera-gpio", },
+	{ .name = "madera-extcon", },
+	{
+		.name = "cs47l85-codec",
+		.parent_supplies = cs47l85_supplies,
+		.num_parent_supplies = ARRAY_SIZE(cs47l85_supplies),
+	},
+};
+
+static const char * const cs47l90_supplies[] = {
+	"MICVDD",
+	"DBVDD2",
+	"DBVDD3",
+	"DBVDD4",
+	"CPVDD1",
+	"CPVDD2",
+};
+
+static const struct mfd_cell cs47l90_devs[] = {
+	{ .name = "madera-pinctrl", },
+	{ .name = "madera-irq", },
+	{ .name = "madera-micsupp", },
+	{ .name = "madera-gpio", },
+	{ .name = "madera-extcon", },
+	{
+		.name = "cs47l90-codec",
+		.parent_supplies = cs47l90_supplies,
+		.num_parent_supplies = ARRAY_SIZE(cs47l90_supplies),
+	},
+};
+
+/* Used by madera-i2c and madera-spi drivers */
+const char *madera_name_from_type(enum madera_type type)
+{
+	switch (type) {
+	case CS47L35:
+		return "CS47L35";
+	case CS47L85:
+		return "CS47L85";
+	case CS47L90:
+		return "CS47L90";
+	case CS47L91:
+		return "CS47L91";
+	case WM1840:
+		return "WM1840";
+	default:
+		return "Unknown";
+	}
+}
+EXPORT_SYMBOL_GPL(madera_name_from_type);
+
+#define MADERA_BOOT_POLL_MAX_INTERVAL_US  5000
+#define MADERA_BOOT_POLL_TIMEOUT_US	 25000
+
+static int madera_wait_for_boot(struct madera *madera)
+{
+	unsigned int val;
+	int ret;
+
+	/*
+	 * We can't use an interrupt as we need to runtime resume to do so,
+	 * so we poll the status bit. This won't race with the interrupt
+	 * handler because it will be blocked on runtime resume.
+	 */
+	ret = regmap_read_poll_timeout(madera->regmap,
+				       MADERA_IRQ1_RAW_STATUS_1,
+				       val,
+				       (val & MADERA_BOOT_DONE_STS1),
+				       MADERA_BOOT_POLL_MAX_INTERVAL_US,
+				       MADERA_BOOT_POLL_TIMEOUT_US);
+
+	if (ret)
+		dev_err(madera->dev, "Polling BOOT_DONE_STS failed: %d\n", ret);
+
+	/*
+	 * BOOT_DONE defaults to unmasked on boot so we must ack it.
+	 * Do this unconditionally to avoid interrupt storms.
+	 */
+	regmap_write(madera->regmap, MADERA_IRQ1_STATUS_1,
+		     MADERA_BOOT_DONE_EINT1);
+
+	pm_runtime_mark_last_busy(madera->dev);
+
+	return ret;
+}
+
+static int madera_soft_reset(struct madera *madera)
+{
+	int ret;
+
+	ret = regmap_write(madera->regmap, MADERA_SOFTWARE_RESET, 0);
+	if (ret != 0) {
+		dev_err(madera->dev, "Failed to soft reset device: %d\n", ret);
+		return ret;
+	}
+
+	/* Allow time for internal clocks to startup after reset */
+	usleep_range(1000, 2000);
+
+	return 0;
+}
+
+static void madera_enable_hard_reset(struct madera *madera)
+{
+	if (!madera->pdata.reset)
+		return;
+
+	/*
+	 * There are many existing out-of-tree users of these codecs that we
+	 * can't break so preserve the expected behaviour of setting the line
+	 * low to assert reset.
+	 */
+	gpiod_set_raw_value_cansleep(madera->pdata.reset, 0);
+}
+
+static void madera_disable_hard_reset(struct madera *madera)
+{
+	if (!madera->pdata.reset)
+		return;
+
+	gpiod_set_raw_value_cansleep(madera->pdata.reset, 1);
+	usleep_range(1000, 2000);
+}
+
+static int __maybe_unused madera_runtime_resume(struct device *dev)
+{
+	struct madera *madera = dev_get_drvdata(dev);
+	int ret;
+
+	dev_dbg(dev, "Leaving sleep mode\n");
+
+	ret = regulator_enable(madera->dcvdd);
+	if (ret) {
+		dev_err(dev, "Failed to enable DCVDD: %d\n", ret);
+		return ret;
+	}
+
+	regcache_cache_only(madera->regmap, false);
+	regcache_cache_only(madera->regmap_32bit, false);
+
+	ret = madera_wait_for_boot(madera);
+	if (ret)
+		goto err;
+
+	ret = regcache_sync(madera->regmap);
+	if (ret) {
+		dev_err(dev, "Failed to restore 16-bit register cache\n");
+		goto err;
+	}
+
+	ret = regcache_sync(madera->regmap_32bit);
+	if (ret) {
+		dev_err(dev, "Failed to restore 32-bit register cache\n");
+		goto err;
+	}
+
+	return 0;
+
+err:
+	regcache_cache_only(madera->regmap_32bit, true);
+	regcache_cache_only(madera->regmap, true);
+	regulator_disable(madera->dcvdd);
+
+	return ret;
+}
+
+static int __maybe_unused madera_runtime_suspend(struct device *dev)
+{
+	struct madera *madera = dev_get_drvdata(dev);
+
+	dev_dbg(madera->dev, "Entering sleep mode\n");
+
+	regcache_cache_only(madera->regmap, true);
+	regcache_mark_dirty(madera->regmap);
+	regcache_cache_only(madera->regmap_32bit, true);
+	regcache_mark_dirty(madera->regmap_32bit);
+
+	regulator_disable(madera->dcvdd);
+
+	return 0;
+}
+
+const struct dev_pm_ops madera_pm_ops = {
+	SET_RUNTIME_PM_OPS(madera_runtime_suspend,
+			   madera_runtime_resume,
+			   NULL)
+};
+EXPORT_SYMBOL_GPL(madera_pm_ops);
+
+const struct of_device_id madera_of_match[] = {
+	{ .compatible = "cirrus,cs47l35", .data = (void *)CS47L35 },
+	{ .compatible = "cirrus,cs47l85", .data = (void *)CS47L85 },
+	{ .compatible = "cirrus,cs47l90", .data = (void *)CS47L90 },
+	{ .compatible = "cirrus,cs47l91", .data = (void *)CS47L91 },
+	{ .compatible = "cirrus,wm1840", .data = (void *)WM1840 },
+	{}
+};
+EXPORT_SYMBOL_GPL(madera_of_match);
+
+static int madera_get_reset_gpio(struct madera *madera)
+{
+	struct gpio_desc *reset;
+	int ret;
+
+	if (madera->pdata.reset)
+		return 0;
+
+	reset = devm_gpiod_get_optional(madera->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(reset)) {
+		ret = PTR_ERR(reset);
+		if (ret != -EPROBE_DEFER)
+			dev_err(madera->dev, "Failed to request /RESET: %d\n",
+				ret);
+		return ret;
+	}
+
+	/*
+	 * A hard reset is needed for full reset of the chip. We allow running
+	 * without hard reset only because it can be useful for early
+	 * prototyping and some debugging, but we need to warn it's not ideal.
+	 */
+	if (!reset)
+		dev_warn(madera->dev,
+			 "Running without reset GPIO is not recommended\n");
+
+	madera->pdata.reset = reset;
+
+	return 0;
+}
+
+static void madera_set_micbias_info(struct madera *madera)
+{
+	/*
+	 * num_childbias is an array because future codecs can have different
+	 * childbiases for each micbias. Unspecified values default to 0.
+	 */
+	switch (madera->type) {
+	case CS47L35:
+		madera->num_micbias = 2;
+		madera->num_childbias[0] = 2;
+		madera->num_childbias[1] = 2;
+		return;
+	case CS47L85:
+	case WM1840:
+		madera->num_micbias = 4;
+		/* no child biases */
+		return;
+	case CS47L90:
+	case CS47L91:
+		madera->num_micbias = 2;
+		madera->num_childbias[0] = 4;
+		madera->num_childbias[1] = 4;
+		return;
+	default:
+		return;
+	}
+}
+
+int madera_dev_init(struct madera *madera)
+{
+	struct device *dev = madera->dev;
+	unsigned int hwid;
+	int (*patch_fn)(struct madera *) = NULL;
+	const struct mfd_cell *mfd_devs;
+	int n_devs = 0;
+	int i, ret;
+
+	dev_set_drvdata(madera->dev, madera);
+	BLOCKING_INIT_NOTIFIER_HEAD(&madera->notifier);
+	madera_set_micbias_info(madera);
+
+	/*
+	 * We need writable hw config info that all children can share.
+	 * Simplest to take one shared copy of pdata struct.
+	 */
+	if (dev_get_platdata(madera->dev)) {
+		memcpy(&madera->pdata, dev_get_platdata(madera->dev),
+		       sizeof(madera->pdata));
+	}
+
+	ret = madera_get_reset_gpio(madera);
+	if (ret)
+		return ret;
+
+	regcache_cache_only(madera->regmap, true);
+	regcache_cache_only(madera->regmap_32bit, true);
+
+	for (i = 0; i < ARRAY_SIZE(madera_core_supplies); i++)
+		madera->core_supplies[i].supply = madera_core_supplies[i];
+
+	madera->num_core_supplies = ARRAY_SIZE(madera_core_supplies);
+
+	/*
+	 * On some codecs DCVDD could be supplied by the internal LDO1.
+	 * For those we must add the LDO1 driver before requesting DCVDD
+	 * No devm_ because we need to control shutdown order of children.
+	 */
+	switch (madera->type) {
+	case CS47L35:
+	case CS47L90:
+	case CS47L91:
+		break;
+	case CS47L85:
+	case WM1840:
+		ret = mfd_add_devices(madera->dev, PLATFORM_DEVID_NONE,
+				      madera_ldo1_devs,
+				      ARRAY_SIZE(madera_ldo1_devs),
+				      NULL, 0, NULL);
+		if (ret) {
+			dev_err(dev, "Failed to add LDO1 child: %d\n", ret);
+			return ret;
+		}
+		break;
+	default:
+		/* No point continuing if the type is unknown */
+		dev_err(madera->dev, "Unknown device type %d\n", madera->type);
+		return -ENODEV;
+	}
+
+	ret = devm_regulator_bulk_get(dev, madera->num_core_supplies,
+				      madera->core_supplies);
+	if (ret) {
+		dev_err(dev, "Failed to request core supplies: %d\n", ret);
+		goto err_devs;
+	}
+
+	/*
+	 * Don't use devres here. If the regulator is one of our children it
+	 * will already have been removed before devres cleanup on this mfd
+	 * driver tries to call put() on it. We need control of shutdown order.
+	 */
+	madera->dcvdd = regulator_get(madera->dev, "DCVDD");
+	if (IS_ERR(madera->dcvdd)) {
+		ret = PTR_ERR(madera->dcvdd);
+		dev_err(dev, "Failed to request DCVDD: %d\n", ret);
+		goto err_devs;
+	}
+
+	ret = regulator_bulk_enable(madera->num_core_supplies,
+				    madera->core_supplies);
+	if (ret) {
+		dev_err(dev, "Failed to enable core supplies: %d\n", ret);
+		goto err_dcvdd;
+	}
+
+	ret = regulator_enable(madera->dcvdd);
+	if (ret) {
+		dev_err(dev, "Failed to enable DCVDD: %d\n", ret);
+		goto err_enable;
+	}
+
+	madera_disable_hard_reset(madera);
+
+	regcache_cache_only(madera->regmap, false);
+	regcache_cache_only(madera->regmap_32bit, false);
+
+	/*
+	 * Now we can power up and verify that this is a chip we know about
+	 * before we start doing any writes to its registers.
+	 */
+	ret = regmap_read(madera->regmap, MADERA_SOFTWARE_RESET, &hwid);
+	if (ret) {
+		dev_err(dev, "Failed to read ID register: %d\n", ret);
+		goto err_reset;
+	}
+
+	switch (hwid) {
+	case CS47L35_SILICON_ID:
+		if (IS_ENABLED(CONFIG_MFD_CS47L35)) {
+			switch (madera->type) {
+			case CS47L35:
+				patch_fn = cs47l35_patch;
+				mfd_devs = cs47l35_devs;
+				n_devs = ARRAY_SIZE(cs47l35_devs);
+				break;
+			default:
+				break;
+			}
+		}
+		break;
+	case CS47L85_SILICON_ID:
+		if (IS_ENABLED(CONFIG_MFD_CS47L85)) {
+			switch (madera->type) {
+			case CS47L85:
+			case WM1840:
+				patch_fn = cs47l85_patch;
+				mfd_devs = cs47l85_devs;
+				n_devs = ARRAY_SIZE(cs47l85_devs);
+				break;
+			default:
+				break;
+			}
+		}
+		break;
+	case CS47L90_SILICON_ID:
+		if (IS_ENABLED(CONFIG_MFD_CS47L90)) {
+			switch (madera->type) {
+			case CS47L90:
+			case CS47L91:
+				patch_fn = cs47l90_patch;
+				mfd_devs = cs47l90_devs;
+				n_devs = ARRAY_SIZE(cs47l90_devs);
+				break;
+			default:
+				break;
+			}
+		}
+		break;
+	default:
+		dev_err(madera->dev, "Unknown device ID: %x\n", hwid);
+		ret = -EINVAL;
+		goto err_reset;
+	}
+
+	if (!n_devs) {
+		dev_err(madera->dev, "Device ID 0x%x not a %s\n", hwid,
+			madera->type_name);
+		ret = -ENODEV;
+		goto err_reset;
+	}
+
+	/*
+	 * It looks like a device we support. If we don't have a hard reset
+	 * we can now attempt a soft reset.
+	 */
+	if (!madera->pdata.reset) {
+		ret = madera_soft_reset(madera);
+		if (ret)
+			goto err_reset;
+	}
+
+	ret = madera_wait_for_boot(madera);
+	if (ret) {
+		dev_err(madera->dev, "Device failed initial boot: %d\n", ret);
+		goto err_reset;
+	}
+
+	ret = regmap_read(madera->regmap, MADERA_HARDWARE_REVISION,
+			  &madera->rev);
+	if (ret) {
+		dev_err(dev, "Failed to read revision register: %d\n", ret);
+		goto err_reset;
+	}
+	madera->rev &= MADERA_HW_REVISION_MASK;
+
+	dev_info(dev, "%s silicon revision %d\n", madera->type_name,
+		 madera->rev);
+
+	/* Apply hardware patch */
+	if (patch_fn) {
+		ret = patch_fn(madera);
+		if (ret) {
+			dev_err(madera->dev, "Failed to apply patch %d\n", ret);
+			goto err_reset;
+		}
+	}
+
+	/* Init 32k clock sourced from MCLK2 */
+	ret = regmap_update_bits(madera->regmap,
+			MADERA_CLOCK_32K_1,
+			MADERA_CLK_32K_ENA_MASK | MADERA_CLK_32K_SRC_MASK,
+			MADERA_CLK_32K_ENA | MADERA_32KZ_MCLK2);
+	if (ret) {
+		dev_err(madera->dev, "Failed to init 32k clock: %d\n", ret);
+		goto err_reset;
+	}
+
+	pm_runtime_set_active(madera->dev);
+	pm_runtime_enable(madera->dev);
+	pm_runtime_set_autosuspend_delay(madera->dev, 100);
+	pm_runtime_use_autosuspend(madera->dev);
+
+	/* No devm_ because we need to control shutdown order of children */
+	ret = mfd_add_devices(madera->dev, PLATFORM_DEVID_NONE,
+			      mfd_devs, n_devs,
+			      NULL, 0, NULL);
+	if (ret) {
+		dev_err(madera->dev, "Failed to add subdevices: %d\n", ret);
+		goto err_pm_runtime;
+	}
+
+	return 0;
+
+err_pm_runtime:
+	pm_runtime_disable(madera->dev);
+err_reset:
+	madera_enable_hard_reset(madera);
+	regulator_disable(madera->dcvdd);
+err_enable:
+	regulator_bulk_disable(madera->num_core_supplies,
+			       madera->core_supplies);
+err_dcvdd:
+	regulator_put(madera->dcvdd);
+err_devs:
+	mfd_remove_devices(dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(madera_dev_init);
+
+int madera_dev_exit(struct madera *madera)
+{
+	/* Prevent any IRQs being serviced while we clean up */
+	disable_irq(madera->irq);
+
+	/*
+	 * DCVDD could be supplied by a child node, we must disable it before
+	 * removing the children, and prevent PM runtime from turning it back on
+	 */
+	pm_runtime_disable(madera->dev);
+
+	regulator_disable(madera->dcvdd);
+	regulator_put(madera->dcvdd);
+
+	mfd_remove_devices(madera->dev);
+	madera_enable_hard_reset(madera);
+
+	regulator_bulk_disable(madera->num_core_supplies,
+			       madera->core_supplies);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(madera_dev_exit);
+
+MODULE_DESCRIPTION("Madera core MFD driver");
+MODULE_AUTHOR("Richard Fitzgerald <rf@opensource.cirrus.com>");
+MODULE_LICENSE("GPL v2");