Add bridged amplifiers to cs42l43

Merge series from Charles Keepax <ckeepax@opensource.cirrus.com>:

In some cs42l43 systems a couple of cs35l56 amplifiers are attached
to the cs42l43's SPI and I2S. On Windows the cs42l43 is controlled
by a SDCA class driver and these two amplifiers are controlled by
firmware running on the cs42l43. However, under Linux the decision
was made to interact with the cs42l43 directly, affording the user
greater control over the audio system. However, this has resulted
in an issue where these two bridged cs35l56 amplifiers are not
populated in ACPI and must be added manually. There is at least an
SDCA extension unit DT entry we can key off.

The process of adding this is handled using a software node, firstly the
ability to add native chip selects to software nodes must be added.
Secondly, an additional flag for naming the SPI devices is added this
allows the machine driver to key to the correct amplifier. Then finally,
the cs42l43 SPI driver adds the two amplifiers directly onto its SPI
bus.

An additional series will follow soon to add the audio machine driver
parts (in the sof-sdw driver), however that is fairly orthogonal to
this part of the process, getting the actual amplifiers registered.

6 files changed, 139 insertions, 18 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 554664efda86..17325e0b7bd5 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -284,6 +284,7 @@ config SPI_COLDFIRE_QSPI
 config SPI_CS42L43
 	tristate "Cirrus Logic CS42L43 SPI controller"
 	depends on MFD_CS42L43 && PINCTRL_CS42L43
+	select GPIO_SWNODE_UNDEFINED
 	help
 	  This enables support for the SPI controller inside the Cirrus Logic
 	  CS42L43 audio codec.
diff --git a/drivers/spi/spi-cs42l43.c b/drivers/spi/spi-cs42l43.c
index aabef9fc84bd..cffd9a177808 100644
--- a/drivers/spi/spi-cs42l43.c
+++ b/drivers/spi/spi-cs42l43.c
@@ -5,10 +5,14 @@
 // Copyright (C) 2022-2023 Cirrus Logic, Inc. and
 //                         Cirrus Logic International Semiconductor Ltd.
 
+#include <linux/acpi.h>
+#include <linux/array_size.h>
 #include <linux/bits.h>
 #include <linux/bitfield.h>
 #include <linux/device.h>
 #include <linux/errno.h>
+#include <linux/gpio/machine.h>
+#include <linux/gpio/property.h>
 #include <linux/mfd/cs42l43.h>
 #include <linux/mfd/cs42l43-regs.h>
 #include <linux/mod_devicetable.h>
@@ -16,6 +20,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/spi/spi.h>
 #include <linux/units.h>
@@ -39,6 +44,44 @@ static const unsigned int cs42l43_clock_divs[] = {
 	2, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30
 };
 
+static const struct software_node ampl = {
+	.name			= "cs35l56-left",
+};
+
+static const struct software_node ampr = {
+	.name			= "cs35l56-right",
+};
+
+static struct spi_board_info ampl_info = {
+	.modalias		= "cs35l56",
+	.max_speed_hz		= 20 * HZ_PER_MHZ,
+	.chip_select		= 0,
+	.mode			= SPI_MODE_0,
+	.swnode			= &ampl,
+};
+
+static struct spi_board_info ampr_info = {
+	.modalias		= "cs35l56",
+	.max_speed_hz		= 20 * HZ_PER_MHZ,
+	.chip_select		= 1,
+	.mode			= SPI_MODE_0,
+	.swnode			= &ampr,
+};
+
+static const struct software_node cs42l43_gpiochip_swnode = {
+	.name			= "cs42l43-pinctrl",
+};
+
+static const struct software_node_ref_args cs42l43_cs_refs[] = {
+	SOFTWARE_NODE_REFERENCE(&cs42l43_gpiochip_swnode, 0, GPIO_ACTIVE_LOW),
+	SOFTWARE_NODE_REFERENCE(&swnode_gpio_undefined),
+};
+
+static const struct property_entry cs42l43_cs_props[] = {
+	PROPERTY_ENTRY_REF_ARRAY("cs-gpios", cs42l43_cs_refs),
+	{}
+};
+
 static int cs42l43_spi_tx(struct regmap *regmap, const u8 *buf, unsigned int len)
 {
 	const u8 *end = buf + len;
@@ -203,16 +246,59 @@ static size_t cs42l43_spi_max_length(struct spi_device *spi)
 	return CS42L43_SPI_MAX_LENGTH;
 }
 
+static bool cs42l43_has_sidecar(struct fwnode_handle *fwnode)
+{
+	static const u32 func_smart_amp = 0x1;
+	struct fwnode_handle *child_fwnode, *ext_fwnode;
+	unsigned int val;
+	u32 function;
+	int ret;
+
+	fwnode_for_each_child_node(fwnode, child_fwnode) {
+		acpi_handle handle = ACPI_HANDLE_FWNODE(child_fwnode);
+
+		ret = acpi_get_local_address(handle, &function);
+		if (ret || function != func_smart_amp)
+			continue;
+
+		ext_fwnode = fwnode_get_named_child_node(child_fwnode,
+				"mipi-sdca-function-expansion-subproperties");
+		if (!ext_fwnode)
+			continue;
+
+		ret = fwnode_property_read_u32(ext_fwnode,
+					       "01fa-cirrus-sidecar-instances",
+					       &val);
+
+		fwnode_handle_put(ext_fwnode);
+
+		if (ret)
+			continue;
+
+		fwnode_handle_put(child_fwnode);
+
+		return !!val;
+	}
+
+	return false;
+}
+
 static void cs42l43_release_of_node(void *data)
 {
 	fwnode_handle_put(data);
 }
 
+static void cs42l43_release_sw_node(void *data)
+{
+	software_node_unregister(&cs42l43_gpiochip_swnode);
+}
+
 static int cs42l43_spi_probe(struct platform_device *pdev)
 {
 	struct cs42l43 *cs42l43 = dev_get_drvdata(pdev->dev.parent);
 	struct cs42l43_spi *priv;
 	struct fwnode_handle *fwnode = dev_fwnode(cs42l43->dev);
+	bool has_sidecar = cs42l43_has_sidecar(fwnode);
 	int ret;
 
 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
@@ -266,14 +352,42 @@ static int cs42l43_spi_probe(struct platform_device *pdev)
 		}
 	}
 
-	device_set_node(&priv->ctlr->dev, fwnode);
+	if (has_sidecar) {
+		ret = software_node_register(&cs42l43_gpiochip_swnode);
+		if (ret)
+			return dev_err_probe(priv->dev, ret,
+					     "Failed to register gpio swnode\n");
+
+		ret = devm_add_action(priv->dev, cs42l43_release_sw_node, NULL);
+		if (ret) {
+			software_node_unregister(&cs42l43_gpiochip_swnode);
+			return ret;
+		}
+
+		ret = device_create_managed_software_node(&priv->ctlr->dev,
+							  cs42l43_cs_props, NULL);
+		if (ret)
+			return dev_err_probe(priv->dev, ret, "Failed to add swnode\n");
+	} else {
+		device_set_node(&priv->ctlr->dev, fwnode);
+	}
 
 	ret = devm_spi_register_controller(priv->dev, priv->ctlr);
-	if (ret) {
-		dev_err(priv->dev, "Failed to register SPI controller: %d\n", ret);
+	if (ret)
+		return dev_err_probe(priv->dev, ret,
+				     "Failed to register SPI controller\n");
+
+	if (has_sidecar) {
+		if (!spi_new_device(priv->ctlr, &ampl_info))
+			return dev_err_probe(priv->dev, -ENODEV,
+					     "Failed to create left amp slave\n");
+
+		if (!spi_new_device(priv->ctlr, &ampr_info))
+			return dev_err_probe(priv->dev, -ENODEV,
+					     "Failed to create right amp slave\n");
 	}
 
-	return ret;
+	return 0;
 }
 
 static const struct platform_device_id cs42l43_spi_id_table[] = {
@@ -291,6 +405,7 @@ static struct platform_driver cs42l43_spi_driver = {
 };
 module_platform_driver(cs42l43_spi_driver);
 
+MODULE_IMPORT_NS(GPIO_SWNODE);
 MODULE_DESCRIPTION("CS42L43 SPI Driver");
 MODULE_AUTHOR("Lucas Tanure <tanureal@opensource.cirrus.com>");
 MODULE_AUTHOR("Maciej Strozek <mstrozek@opensource.cirrus.com>");
diff --git a/drivers/spi/spi-fsl-lpspi.c b/drivers/spi/spi-fsl-lpspi.c
index 079035db7dd8..92a662d1b55c 100644
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -852,39 +852,39 @@ static int fsl_lpspi_probe(struct platform_device *pdev)
 	fsl_lpspi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 	if (IS_ERR(fsl_lpspi->base)) {
 		ret = PTR_ERR(fsl_lpspi->base);
-		goto out_controller_put;
+		return ret;
 	}
 	fsl_lpspi->base_phys = res->start;
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		ret = irq;
-		goto out_controller_put;
+		return ret;
 	}
 
 	ret = devm_request_irq(&pdev->dev, irq, fsl_lpspi_isr, 0,
 			       dev_name(&pdev->dev), fsl_lpspi);
 	if (ret) {
 		dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret);
-		goto out_controller_put;
+		return ret;
 	}
 
 	fsl_lpspi->clk_per = devm_clk_get(&pdev->dev, "per");
 	if (IS_ERR(fsl_lpspi->clk_per)) {
 		ret = PTR_ERR(fsl_lpspi->clk_per);
-		goto out_controller_put;
+		return ret;
 	}
 
 	fsl_lpspi->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
 	if (IS_ERR(fsl_lpspi->clk_ipg)) {
 		ret = PTR_ERR(fsl_lpspi->clk_ipg);
-		goto out_controller_put;
+		return ret;
 	}
 
 	/* enable the clock */
 	ret = fsl_lpspi_init_rpm(fsl_lpspi);
 	if (ret)
-		goto out_controller_put;
+		return ret;
 
 	ret = pm_runtime_get_sync(fsl_lpspi->dev);
 	if (ret < 0) {
@@ -945,8 +945,6 @@ out_pm_get:
 	pm_runtime_dont_use_autosuspend(fsl_lpspi->dev);
 	pm_runtime_put_sync(fsl_lpspi->dev);
 	pm_runtime_disable(fsl_lpspi->dev);
-out_controller_put:
-	spi_controller_put(controller);
 
 	return ret;
 }
diff --git a/drivers/spi/spi-pci1xxxx.c b/drivers/spi/spi-pci1xxxx.c
index 969965d7bc98..cc18d320370f 100644
--- a/drivers/spi/spi-pci1xxxx.c
+++ b/drivers/spi/spi-pci1xxxx.c
@@ -725,6 +725,8 @@ static int pci1xxxx_spi_probe(struct pci_dev *pdev, const struct pci_device_id *
 		spi_bus->spi_int[iter] = devm_kzalloc(&pdev->dev,
 						      sizeof(struct pci1xxxx_spi_internal),
 						      GFP_KERNEL);
+		if (!spi_bus->spi_int[iter])
+			return -ENOMEM;
 		spi_sub_ptr = spi_bus->spi_int[iter];
 		spi_sub_ptr->spi_host = devm_spi_alloc_host(dev, sizeof(struct spi_controller));
 		if (!spi_sub_ptr->spi_host)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 9fcbe040cb2f..f726d8670428 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -430,7 +430,7 @@ static bool s3c64xx_spi_can_dma(struct spi_controller *host,
 	struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host);
 
 	if (sdd->rx_dma.ch && sdd->tx_dma.ch)
-		return xfer->len > sdd->fifo_depth;
+		return xfer->len >= sdd->fifo_depth;
 
 	return false;
 }
@@ -826,10 +826,9 @@ static int s3c64xx_spi_transfer_one(struct spi_controller *host,
 			return status;
 	}
 
-	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
+	if (!is_polling(sdd) && xfer->len >= fifo_len &&
 	    sdd->rx_dma.ch && sdd->tx_dma.ch) {
 		use_dma = 1;
-
 	} else if (xfer->len >= fifo_len) {
 		tx_buf = xfer->tx_buf;
 		rx_buf = xfer->rx_buf;
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 6c620df6a14f..34fca94b2b5b 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -597,10 +597,16 @@ EXPORT_SYMBOL_GPL(spi_alloc_device);
 
 static void spi_dev_set_name(struct spi_device *spi)
 {
-	struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
+	struct device *dev = &spi->dev;
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
 
-	if (adev) {
-		dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
+	if (is_acpi_device_node(fwnode)) {
+		dev_set_name(dev, "spi-%s", acpi_dev_name(to_acpi_device_node(fwnode)));
+		return;
+	}
+
+	if (is_software_node(fwnode)) {
+		dev_set_name(dev, "spi-%pfwP", fwnode);
 		return;
 	}