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path: root/drivers/pinctrl/pinctrl-mcp23s08_spi.c
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Diffstat (limited to 'drivers/pinctrl/pinctrl-mcp23s08_spi.c')
-rw-r--r--drivers/pinctrl/pinctrl-mcp23s08_spi.c271
1 files changed, 271 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-mcp23s08_spi.c b/drivers/pinctrl/pinctrl-mcp23s08_spi.c
new file mode 100644
index 000000000..ea059b9c5
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-mcp23s08_spi.c
@@ -0,0 +1,271 @@
+// 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);
+ if (!mcp->chip.label)
+ return -ENOMEM;
+
+ config = &mcp23x08_regmap;
+ name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
+ if (!name)
+ return -ENOMEM;
+
+ break;
+
+ case MCP_TYPE_S17:
+ mcp->reg_shift = 1;
+ mcp->chip.ngpio = 16;
+ mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr);
+ if (!mcp->chip.label)
+ return -ENOMEM;
+
+ config = &mcp23x17_regmap;
+ name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
+ if (!name)
+ return -ENOMEM;
+
+ 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))
+ dev_err(dev, "regmap init failed for %s\n", mcp->chip.label);
+ return PTR_ERR_OR_ZERO(mcp->regmap);
+}
+
+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");