pinctrl: mcp23s08: Split to three parts: core, I²C, SPI

Split the driver to three parts: core, I²C, SPI.
No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200407173849.43628-9-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 262 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinctrl-mcp23s08_spi.c b/drivers/pinctrl/pinctrl-mcp23s08_spi.c
new file mode 100644
index 000000000000..e06fb885fd2b
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-mcp23s08_spi.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* MCP23S08 SPI GPIO driver */
+
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include "pinctrl-mcp23s08.h"
+
+#define MCP_MAX_DEV_PER_CS	8
+
+/*
+ * A given spi_device can represent up to eight mcp23sxx chips
+ * sharing the same chipselect but using different addresses
+ * (e.g. chips #0 and #3 might be populated, but not #1 or #2).
+ * Driver data holds all the per-chip data.
+ */
+struct mcp23s08_driver_data {
+	unsigned		ngpio;
+	struct mcp23s08		*mcp[8];
+	struct mcp23s08		chip[];
+};
+
+static int mcp23sxx_spi_write(void *context, const void *data, size_t count)
+{
+	struct mcp23s08 *mcp = context;
+	struct spi_device *spi = to_spi_device(mcp->dev);
+	struct spi_message m;
+	struct spi_transfer t[2] = { { .tx_buf = &mcp->addr, .len = 1, },
+				     { .tx_buf = data, .len = count, }, };
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t[0], &m);
+	spi_message_add_tail(&t[1], &m);
+
+	return spi_sync(spi, &m);
+}
+
+static int mcp23sxx_spi_gather_write(void *context,
+				const void *reg, size_t reg_size,
+				const void *val, size_t val_size)
+{
+	struct mcp23s08 *mcp = context;
+	struct spi_device *spi = to_spi_device(mcp->dev);
+	struct spi_message m;
+	struct spi_transfer t[3] = { { .tx_buf = &mcp->addr, .len = 1, },
+				     { .tx_buf = reg, .len = reg_size, },
+				     { .tx_buf = val, .len = val_size, }, };
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t[0], &m);
+	spi_message_add_tail(&t[1], &m);
+	spi_message_add_tail(&t[2], &m);
+
+	return spi_sync(spi, &m);
+}
+
+static int mcp23sxx_spi_read(void *context, const void *reg, size_t reg_size,
+				void *val, size_t val_size)
+{
+	struct mcp23s08 *mcp = context;
+	struct spi_device *spi = to_spi_device(mcp->dev);
+	u8 tx[2];
+
+	if (reg_size != 1)
+		return -EINVAL;
+
+	tx[0] = mcp->addr | 0x01;
+	tx[1] = *((u8 *) reg);
+
+	return spi_write_then_read(spi, tx, sizeof(tx), val, val_size);
+}
+
+static const struct regmap_bus mcp23sxx_spi_regmap = {
+	.write = mcp23sxx_spi_write,
+	.gather_write = mcp23sxx_spi_gather_write,
+	.read = mcp23sxx_spi_read,
+};
+
+static int mcp23s08_spi_regmap_init(struct mcp23s08 *mcp, struct device *dev,
+				    unsigned int addr, unsigned int type)
+{
+	const struct regmap_config *config;
+	struct regmap_config *copy;
+	const char *name;
+
+	switch (type) {
+	case MCP_TYPE_S08:
+		mcp->reg_shift = 0;
+		mcp->chip.ngpio = 8;
+		mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s08.%d", addr);
+
+		config = &mcp23x08_regmap;
+		name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
+		break;
+
+	case MCP_TYPE_S17:
+		mcp->reg_shift = 1;
+		mcp->chip.ngpio = 16;
+		mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr);
+
+		config = &mcp23x17_regmap;
+		name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
+		break;
+
+	case MCP_TYPE_S18:
+		mcp->reg_shift = 1;
+		mcp->chip.ngpio = 16;
+		mcp->chip.label = "mcp23s18";
+
+		config = &mcp23x17_regmap;
+		name = config->name;
+		break;
+
+	default:
+		dev_err(dev, "invalid device type (%d)\n", type);
+		return -EINVAL;
+	}
+
+	copy = devm_kmemdup(dev, &config, sizeof(config), GFP_KERNEL);
+	if (!copy)
+		return -ENOMEM;
+
+	copy->name = name;
+
+	mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp, copy);
+	if (IS_ERR(mcp->regmap))
+		return PTR_ERR(mcp->regmap);
+
+	return 0;
+}
+
+static int mcp23s08_probe(struct spi_device *spi)
+{
+	struct device *dev = &spi->dev;
+	struct mcp23s08_driver_data *data;
+	unsigned long spi_present_mask;
+	const void *match;
+	unsigned int addr;
+	unsigned int ngpio = 0;
+	int chips;
+	int type;
+	int ret;
+	u32 v;
+
+	match = device_get_match_data(dev);
+	if (match)
+		type = (int)(uintptr_t)match;
+	else
+		type = spi_get_device_id(spi)->driver_data;
+
+	ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v);
+	if (ret) {
+		ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v);
+		if (ret) {
+			dev_err(dev, "missing spi-present-mask");
+			return ret;
+		}
+	}
+	spi_present_mask = v;
+
+	if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) {
+		dev_err(dev, "invalid spi-present-mask");
+		return -ENODEV;
+	}
+
+	chips = hweight_long(spi_present_mask);
+
+	data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, data);
+
+	for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) {
+		data->mcp[addr] = &data->chip[--chips];
+		data->mcp[addr]->irq = spi->irq;
+
+		ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, type);
+		if (ret)
+			return ret;
+
+		data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL,
+								    "mcp23xxx-pinctrl.%d",
+								    addr);
+		if (!data->mcp[addr]->pinctrl_desc.name)
+			return -ENOMEM;
+
+		ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1), type, -1);
+		if (ret < 0)
+			return ret;
+
+		ngpio += data->mcp[addr]->chip.ngpio;
+	}
+	data->ngpio = ngpio;
+
+	return 0;
+}
+
+static const struct spi_device_id mcp23s08_ids[] = {
+	{ "mcp23s08", MCP_TYPE_S08 },
+	{ "mcp23s17", MCP_TYPE_S17 },
+	{ "mcp23s18", MCP_TYPE_S18 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
+
+static const struct of_device_id mcp23s08_spi_of_match[] = {
+	{
+		.compatible = "microchip,mcp23s08",
+		.data = (void *) MCP_TYPE_S08,
+	},
+	{
+		.compatible = "microchip,mcp23s17",
+		.data = (void *) MCP_TYPE_S17,
+	},
+	{
+		.compatible = "microchip,mcp23s18",
+		.data = (void *) MCP_TYPE_S18,
+	},
+/* NOTE: The use of the mcp prefix is deprecated and will be removed. */
+	{
+		.compatible = "mcp,mcp23s08",
+		.data = (void *) MCP_TYPE_S08,
+	},
+	{
+		.compatible = "mcp,mcp23s17",
+		.data = (void *) MCP_TYPE_S17,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
+
+static struct spi_driver mcp23s08_driver = {
+	.probe		= mcp23s08_probe,
+	.id_table	= mcp23s08_ids,
+	.driver = {
+		.name	= "mcp23s08",
+		.of_match_table = mcp23s08_spi_of_match,
+	},
+};
+
+static int __init mcp23s08_spi_init(void)
+{
+	return spi_register_driver(&mcp23s08_driver);
+}
+
+/*
+ * Register after SPI postcore initcall and before
+ * subsys initcalls that may rely on these GPIOs.
+ */
+subsys_initcall(mcp23s08_spi_init);
+
+static void mcp23s08_spi_exit(void)
+{
+	spi_unregister_driver(&mcp23s08_driver);
+}
+module_exit(mcp23s08_spi_exit);
+
+MODULE_LICENSE("GPL");