Initial import

1 files changed, 201 insertions, 0 deletions

diff --git a/drivers/mfd/mc13xxx-spi.c b/drivers/mfd/mc13xxx-spi.c
new file mode 100644
index 000000000..58a170e45
--- /dev/null
+++ b/drivers/mfd/mc13xxx-spi.c
@@ -0,0 +1,201 @@
+/*
+ * Copyright 2009-2010 Pengutronix
+ * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
+ *
+ * loosely based on an earlier driver that has
+ * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/mc13xxx.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/err.h>
+#include <linux/spi/spi.h>
+
+#include "mc13xxx.h"
+
+static const struct spi_device_id mc13xxx_device_id[] = {
+	{
+		.name = "mc13783",
+		.driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783,
+	}, {
+		.name = "mc13892",
+		.driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892,
+	}, {
+		.name = "mc34708",
+		.driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
+
+static const struct of_device_id mc13xxx_dt_ids[] = {
+	{ .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, },
+	{ .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, },
+	{ .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
+
+static const struct regmap_config mc13xxx_regmap_spi_config = {
+	.reg_bits = 7,
+	.pad_bits = 1,
+	.val_bits = 24,
+	.write_flag_mask = 0x80,
+
+	.max_register = MC13XXX_NUMREGS,
+
+	.cache_type = REGCACHE_NONE,
+	.use_single_rw = 1,
+};
+
+static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size,
+				void *val, size_t val_size)
+{
+	unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0};
+	unsigned char r[4];
+	unsigned char *p = val;
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+	struct spi_transfer t = {
+		.tx_buf = w,
+		.rx_buf = r,
+		.len = 4,
+	};
+
+	struct spi_message m;
+	int ret;
+
+	if (val_size != 3 || reg_size != 1)
+		return -ENOTSUPP;
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t, &m);
+	ret = spi_sync(spi, &m);
+
+	memcpy(p, &r[1], 3);
+
+	return ret;
+}
+
+static int mc13xxx_spi_write(void *context, const void *data, size_t count)
+{
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+	const char *reg = data;
+
+	if (count != 4)
+		return -ENOTSUPP;
+
+	/* include errata fix for spi audio problems */
+	if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC)
+		spi_write(spi, data, count);
+
+	return spi_write(spi, data, count);
+}
+
+/*
+ * We cannot use regmap-spi generic bus implementation here.
+ * The MC13783 chip will get corrupted if CS signal is deasserted
+ * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller
+ * has the following errata (DSPhl22960):
+ * "The CSPI negates SS when the FIFO becomes empty with
+ * SSCTL= 0. Software cannot guarantee that the FIFO will not
+ * drain because of higher priority interrupts and the
+ * non-realtime characteristics of the operating system. As a
+ * result, the SS will negate before all of the data has been
+ * transferred to/from the peripheral."
+ * We workaround this by accessing the SPI controller with a
+ * single transfert.
+ */
+
+static struct regmap_bus regmap_mc13xxx_bus = {
+	.write = mc13xxx_spi_write,
+	.read = mc13xxx_spi_read,
+};
+
+static int mc13xxx_spi_probe(struct spi_device *spi)
+{
+	struct mc13xxx *mc13xxx;
+	int ret;
+
+	mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL);
+	if (!mc13xxx)
+		return -ENOMEM;
+
+	dev_set_drvdata(&spi->dev, mc13xxx);
+
+	spi->mode = SPI_MODE_0 | SPI_CS_HIGH;
+
+	mc13xxx->irq = spi->irq;
+
+	spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
+	ret = spi_setup(spi);
+	if (ret)
+		return ret;
+
+	mc13xxx->regmap = devm_regmap_init(&spi->dev, &regmap_mc13xxx_bus,
+					   &spi->dev,
+					   &mc13xxx_regmap_spi_config);
+	if (IS_ERR(mc13xxx->regmap)) {
+		ret = PTR_ERR(mc13xxx->regmap);
+		dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret);
+		return ret;
+	}
+
+	if (spi->dev.of_node) {
+		const struct of_device_id *of_id =
+			of_match_device(mc13xxx_dt_ids, &spi->dev);
+
+		mc13xxx->variant = of_id->data;
+	} else {
+		const struct spi_device_id *id_entry = spi_get_device_id(spi);
+
+		mc13xxx->variant = (void *)id_entry->driver_data;
+	}
+
+	return mc13xxx_common_init(&spi->dev);
+}
+
+static int mc13xxx_spi_remove(struct spi_device *spi)
+{
+	return mc13xxx_common_exit(&spi->dev);
+}
+
+static struct spi_driver mc13xxx_spi_driver = {
+	.id_table = mc13xxx_device_id,
+	.driver = {
+		.name = "mc13xxx",
+		.owner = THIS_MODULE,
+		.of_match_table = mc13xxx_dt_ids,
+	},
+	.probe = mc13xxx_spi_probe,
+	.remove = mc13xxx_spi_remove,
+};
+
+static int __init mc13xxx_init(void)
+{
+	return spi_register_driver(&mc13xxx_spi_driver);
+}
+subsys_initcall(mc13xxx_init);
+
+static void __exit mc13xxx_exit(void)
+{
+	spi_unregister_driver(&mc13xxx_spi_driver);
+}
+module_exit(mc13xxx_exit);
+
+MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");
+MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
+MODULE_LICENSE("GPL v2");