mfd: cs42l43: Add support for cs42l43 core driver

The CS42L43 is an audio CODEC with integrated MIPI SoundWire interface
(Version 1.2.1 compliant), I2C, SPI, and I2S/TDM interfaces designed
for portable applications. It provides a high dynamic range, stereo
DAC for headphone output, two integrated Class D amplifiers for
loudspeakers, and two ADCs for wired headset microphone input or
stereo line input. PDM inputs are provided for digital microphones.

The MFD component registers and initialises the device and provides
PM/system power management.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230804104602.395892-4-ckeepax@opensource.cirrus.com
Signed-off-by: Lee Jones <lee@kernel.org>

1 files changed, 239 insertions, 0 deletions

diff --git a/drivers/mfd/cs42l43-sdw.c b/drivers/mfd/cs42l43-sdw.c
new file mode 100644
index 000000000000..7392b3d2e6b9
--- /dev/null
+++ b/drivers/mfd/cs42l43-sdw.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CS42L43 SoundWire driver
+ *
+ * Copyright (C) 2022-2023 Cirrus Logic, Inc. and
+ *                         Cirrus Logic International Semiconductor Ltd.
+ */
+
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/mfd/cs42l43-regs.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/soundwire/sdw.h>
+#include <linux/soundwire/sdw_registers.h>
+#include <linux/soundwire/sdw_type.h>
+
+#include "cs42l43.h"
+
+enum cs42l43_sdw_ports {
+	CS42L43_DMIC_DEC_ASP_PORT = 1,
+	CS42L43_SPK_TX_PORT,
+	CS42L43_SPDIF_HP_PORT,
+	CS42L43_SPK_RX_PORT,
+	CS42L43_ASP_PORT,
+};
+
+static const struct regmap_config cs42l43_sdw_regmap = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.reg_format_endian	= REGMAP_ENDIAN_LITTLE,
+	.val_format_endian	= REGMAP_ENDIAN_LITTLE,
+
+	.max_register		= CS42L43_MCU_RAM_MAX,
+	.readable_reg		= cs42l43_readable_register,
+	.volatile_reg		= cs42l43_volatile_register,
+	.precious_reg		= cs42l43_precious_register,
+
+	.cache_type		= REGCACHE_MAPLE,
+	.reg_defaults		= cs42l43_reg_default,
+	.num_reg_defaults	= ARRAY_SIZE(cs42l43_reg_default),
+};
+
+static int cs42l43_read_prop(struct sdw_slave *sdw)
+{
+	struct sdw_slave_prop *prop = &sdw->prop;
+	struct device *dev = &sdw->dev;
+	struct sdw_dpn_prop *dpn;
+	unsigned long addr;
+	int nval;
+	int i;
+	u32 bit;
+
+	prop->use_domain_irq = true;
+	prop->paging_support = true;
+	prop->wake_capable = true;
+	prop->source_ports = BIT(CS42L43_DMIC_DEC_ASP_PORT) | BIT(CS42L43_SPK_TX_PORT);
+	prop->sink_ports = BIT(CS42L43_SPDIF_HP_PORT) |
+			   BIT(CS42L43_SPK_RX_PORT) | BIT(CS42L43_ASP_PORT);
+	prop->quirks = SDW_SLAVE_QUIRKS_INVALID_INITIAL_PARITY;
+	prop->scp_int1_mask = SDW_SCP_INT1_BUS_CLASH | SDW_SCP_INT1_PARITY |
+			      SDW_SCP_INT1_IMPL_DEF;
+
+	nval = hweight32(prop->source_ports);
+	prop->src_dpn_prop = devm_kcalloc(dev, nval, sizeof(*prop->src_dpn_prop),
+					  GFP_KERNEL);
+	if (!prop->src_dpn_prop)
+		return -ENOMEM;
+
+	i = 0;
+	dpn = prop->src_dpn_prop;
+	addr = prop->source_ports;
+	for_each_set_bit(bit, &addr, 32) {
+		dpn[i].num = bit;
+		dpn[i].max_ch = 2;
+		dpn[i].type = SDW_DPN_FULL;
+		dpn[i].max_word = 24;
+		i++;
+	}
+	/*
+	 * All ports are 2 channels max, except the first one,
+	 * CS42L43_DMIC_DEC_ASP_PORT.
+	 */
+	dpn[CS42L43_DMIC_DEC_ASP_PORT].max_ch = 4;
+
+	nval = hweight32(prop->sink_ports);
+	prop->sink_dpn_prop = devm_kcalloc(dev, nval, sizeof(*prop->sink_dpn_prop),
+					   GFP_KERNEL);
+	if (!prop->sink_dpn_prop)
+		return -ENOMEM;
+
+	i = 0;
+	dpn = prop->sink_dpn_prop;
+	addr = prop->sink_ports;
+	for_each_set_bit(bit, &addr, 32) {
+		dpn[i].num = bit;
+		dpn[i].max_ch = 2;
+		dpn[i].type = SDW_DPN_FULL;
+		dpn[i].max_word = 24;
+		i++;
+	}
+
+	return 0;
+}
+
+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)
+{
+	/*
+	 * The IRQ itself was handled through the regmap_irq handler, this is
+	 * just clearing up the additional Cirrus SoundWire registers that are
+	 * not covered by the SoundWire framework or the IRQ handler itself.
+	 * 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, CS42L43_INT_STAT_GEN1_MASK);
+
+	return 0;
+}
+
+static int cs42l43_sdw_bus_config(struct sdw_slave *sdw,
+				  struct sdw_bus_params *params)
+{
+	struct cs42l43 *cs42l43 = dev_get_drvdata(&sdw->dev);
+	int ret = 0;
+
+	mutex_lock(&cs42l43->pll_lock);
+
+	if (cs42l43->sdw_freq != params->curr_dr_freq / 2) {
+		if (cs42l43->sdw_pll_active) {
+			dev_err(cs42l43->dev,
+				"PLL active can't change SoundWire bus clock\n");
+			ret = -EBUSY;
+		} else {
+			cs42l43->sdw_freq = params->curr_dr_freq / 2;
+		}
+	}
+
+	mutex_unlock(&cs42l43->pll_lock);
+
+	return ret;
+}
+
+static const struct sdw_slave_ops cs42l43_sdw_ops = {
+	.read_prop		= cs42l43_read_prop,
+	.update_status		= cs42l43_sdw_update_status,
+	.interrupt_callback	= cs42l43_sdw_interrupt,
+	.bus_config		= cs42l43_sdw_bus_config,
+};
+
+static int cs42l43_sdw_probe(struct sdw_slave *sdw, const struct sdw_device_id *id)
+{
+	struct cs42l43 *cs42l43;
+	struct device *dev = &sdw->dev;
+	int ret;
+
+	cs42l43 = devm_kzalloc(dev, sizeof(*cs42l43), GFP_KERNEL);
+	if (!cs42l43)
+		return -ENOMEM;
+
+	cs42l43->dev = dev;
+	cs42l43->sdw = sdw;
+
+	cs42l43->regmap = devm_regmap_init_sdw(sdw, &cs42l43_sdw_regmap);
+	if (IS_ERR(cs42l43->regmap)) {
+		ret = PTR_ERR(cs42l43->regmap);
+		dev_err(cs42l43->dev, "Failed to allocate regmap: %d\n", ret);
+		return ret;
+	}
+
+	return cs42l43_dev_probe(cs42l43);
+}
+
+static int cs42l43_sdw_remove(struct sdw_slave *sdw)
+{
+	struct cs42l43 *cs42l43 = dev_get_drvdata(&sdw->dev);
+
+	cs42l43_dev_remove(cs42l43);
+
+	return 0;
+}
+
+static const struct sdw_device_id cs42l43_sdw_id[] = {
+	SDW_SLAVE_ENTRY(0x01FA, 0x4243, 0),
+	{}
+};
+MODULE_DEVICE_TABLE(sdw, cs42l43_sdw_id);
+
+static struct sdw_driver cs42l43_sdw_driver = {
+	.driver = {
+		.name		= "cs42l43",
+		.pm		= pm_ptr(&cs42l43_pm_ops),
+	},
+
+	.probe		= cs42l43_sdw_probe,
+	.remove		= cs42l43_sdw_remove,
+	.id_table	= cs42l43_sdw_id,
+	.ops		= &cs42l43_sdw_ops,
+};
+module_sdw_driver(cs42l43_sdw_driver);
+
+MODULE_IMPORT_NS(MFD_CS42L43);
+
+MODULE_DESCRIPTION("CS42L43 SoundWire Driver");
+MODULE_AUTHOR("Lucas Tanure <tanureal@opensource.cirrus.com>");
+MODULE_LICENSE("GPL");