[PATCH 2/2] mfd/stmpe: Add support for SPI interface
From: Viresh Kumar
Date: Tue Nov 08 2011 - 02:06:27 EST
Few STMPE controller can have register interface over SPI or I2C. Current
implementation only supports I2C.
This patch adds support for SPI interface for accessing STMPE's address space.
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxx>
---
drivers/mfd/Kconfig | 8 ++-
drivers/mfd/Makefile | 1 +
drivers/mfd/stmpe-spi.c | 147 +++++++++++++++++++++++++++++++++++++++++++++++
drivers/mfd/stmpe.h | 1 +
4 files changed, 156 insertions(+), 1 deletions(-)
create mode 100644 drivers/mfd/stmpe-spi.c
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 2f8561a..ebfb296 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -272,7 +272,7 @@ config TWL6040_CORE
config MFD_STMPE
bool "Support STMicroelectronics STMPE"
- depends on I2C=y && GENERIC_HARDIRQS
+ depends on (I2C=y || SPI_MASTER=y) && GENERIC_HARDIRQS
select MFD_CORE
help
Support for the STMPE family of I/O Expanders from
@@ -302,6 +302,12 @@ config STMPE_I2C
default y
help
This is used to enable I2C interface of STMPE
+
+config STMPE_SPI
+ bool "STMPE SPI Inteface"
+ depends on SPI_MASTER
+ help
+ This is used to enable SPI interface of STMPE
endmenu
config MFD_TC3589X
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 24ee9bb..eac1e9f 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_MFD_TI_SSP) += ti-ssp.o
obj-$(CONFIG_MFD_STMPE) += stmpe.o
obj-$(CONFIG_STMPE_I2C) += stmpe-i2c.o
+obj-$(CONFIG_STMPE_SPI) += stmpe-spi.o
obj-$(CONFIG_MFD_TC3589X) += tc3589x.o
obj-$(CONFIG_MFD_T7L66XB) += t7l66xb.o tmio_core.o
obj-$(CONFIG_MFD_TC6387XB) += tc6387xb.o tmio_core.o
diff --git a/drivers/mfd/stmpe-spi.c b/drivers/mfd/stmpe-spi.c
new file mode 100644
index 0000000..6f1c0ad3
--- /dev/null
+++ b/drivers/mfd/stmpe-spi.c
@@ -0,0 +1,147 @@
+/*
+ * ST Microelectronics MFD: stmpe's spi client specific driver
+ *
+ * Copyright (C) ST Microelectronics SA 2011
+ *
+ * License Terms: GNU General Public License, version 2
+ * Author: Viresh Kumar <viresh.kumar@xxxxxx> for ST Microelectronics
+ */
+
+#include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.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;
+
+ dev_set_drvdata(stmpe->dev, stmpe);
+ 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 __devinit
+stmpe_spi_probe(struct spi_device *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);
+}
+
+static int __devexit stmpe_spi_remove(struct spi_device *spi)
+{
+ struct stmpe *stmpe = dev_get_drvdata(&spi->dev);
+
+ return stmpe_remove(stmpe);
+}
+
+static const struct spi_device_id stmpe_spi_id[] = {
+ { "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",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+#ifdef CONFIG_PM
+ .pm = &stmpe_dev_pm_ops,
+#endif
+ },
+ .probe = stmpe_spi_probe,
+ .remove = __devexit_p(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 core driver");
+MODULE_AUTHOR("Rabin Vincent <rabin.vincent@xxxxxxxxxxxxxx>");
diff --git a/drivers/mfd/stmpe.h b/drivers/mfd/stmpe.h
index c716044..908f482 100644
--- a/drivers/mfd/stmpe.h
+++ b/drivers/mfd/stmpe.h
@@ -120,6 +120,7 @@ int stmpe_remove(struct stmpe *stmpe);
#define STMPE811_REG_CHIP_ID 0x00
#define STMPE811_REG_SYS_CTRL2 0x04
+#define STMPE811_REG_SPI_CFG 0x08
#define STMPE811_REG_INT_CTRL 0x09
#define STMPE811_REG_INT_EN 0x0A
#define STMPE811_REG_INT_STA 0x0B
--
1.7.2.2
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