1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/mfd/stmpe-spi.c b/drivers/mfd/stmpe-spi.c
new file mode 100644
index 000000000..7351734f7
--- /dev/null
+++ b/drivers/mfd/stmpe-spi.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ST Microelectronics MFD: stmpe's spi client specific driver
+ *
+ * Copyright (C) ST Microelectronics SA 2011
+ *
+ * Author: Viresh Kumar <vireshk@kernel.org> for ST Microelectronics
+ */
+
+#include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/types.h>
+#include "stmpe.h"
+
+#define READ_CMD	(1 << 7)
+
+static int spi_reg_read(struct stmpe *stmpe, u8 reg)
+{
+	struct spi_device *spi = stmpe->client;
+	int status = spi_w8r16(spi, reg | READ_CMD);
+
+	return (status < 0) ? status : status >> 8;
+}
+
+static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
+{
+	struct spi_device *spi = stmpe->client;
+	u16 cmd = (val << 8) | reg;
+
+	return spi_write(spi, (const u8 *)&cmd, 2);
+}
+
+static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
+{
+	int ret, i;
+
+	for (i = 0; i < length; i++) {
+		ret = spi_reg_read(stmpe, reg + i);
+		if (ret < 0)
+			return ret;
+		*(values + i) = ret;
+	}
+
+	return 0;
+}
+
+static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,
+		const u8 *values)
+{
+	int ret = 0, i;
+
+	for (i = length; i > 0; i--, reg++) {
+		ret = spi_reg_write(stmpe, reg, *(values + i - 1));
+		if (ret < 0)
+			return ret;
+	}
+
+	return ret;
+}
+
+static void spi_init(struct stmpe *stmpe)
+{
+	struct spi_device *spi = stmpe->client;
+
+	spi->bits_per_word = 8;
+
+	/* This register is only present for stmpe811 */
+	if (stmpe->variant->id_val == 0x0811)
+		spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);
+
+	if (spi_setup(spi) < 0)
+		dev_dbg(&spi->dev, "spi_setup failed\n");
+}
+
+static struct stmpe_client_info spi_ci = {
+	.read_byte = spi_reg_read,
+	.write_byte = spi_reg_write,
+	.read_block = spi_block_read,
+	.write_block = spi_block_write,
+	.init = spi_init,
+};
+
+static int
+stmpe_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *id = spi_get_device_id(spi);
+
+	/* don't exceed max specified rate - 1MHz - Limitation of STMPE */
+	if (spi->max_speed_hz > 1000000) {
+		dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
+				(spi->max_speed_hz/1000));
+		return -EINVAL;
+	}
+
+	spi_ci.irq = spi->irq;
+	spi_ci.client = spi;
+	spi_ci.dev = &spi->dev;
+
+	return stmpe_probe(&spi_ci, id->driver_data);
+}
+
+static int stmpe_spi_remove(struct spi_device *spi)
+{
+	struct stmpe *stmpe = spi_get_drvdata(spi);
+
+	return stmpe_remove(stmpe);
+}
+
+static const struct of_device_id stmpe_spi_of_match[] = {
+	{ .compatible = "st,stmpe610", },
+	{ .compatible = "st,stmpe801", },
+	{ .compatible = "st,stmpe811", },
+	{ .compatible = "st,stmpe1601", },
+	{ .compatible = "st,stmpe2401", },
+	{ .compatible = "st,stmpe2403", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, stmpe_spi_of_match);
+
+static const struct spi_device_id stmpe_spi_id[] = {
+	{ "stmpe610", STMPE610 },
+	{ "stmpe801", STMPE801 },
+	{ "stmpe811", STMPE811 },
+	{ "stmpe1601", STMPE1601 },
+	{ "stmpe2401", STMPE2401 },
+	{ "stmpe2403", STMPE2403 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, stmpe_id);
+
+static struct spi_driver stmpe_spi_driver = {
+	.driver = {
+		.name	= "stmpe-spi",
+		.of_match_table = of_match_ptr(stmpe_spi_of_match),
+#ifdef CONFIG_PM
+		.pm	= &stmpe_dev_pm_ops,
+#endif
+	},
+	.probe		= stmpe_spi_probe,
+	.remove		= stmpe_spi_remove,
+	.id_table	= stmpe_spi_id,
+};
+
+static int __init stmpe_init(void)
+{
+	return spi_register_driver(&stmpe_spi_driver);
+}
+subsys_initcall(stmpe_init);
+
+static void __exit stmpe_exit(void)
+{
+	spi_unregister_driver(&stmpe_spi_driver);
+}
+module_exit(stmpe_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
+MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");