mfd/stmpe: Add SPI interface support

Few STMPE controller can have register interface over SPI or I2C. Current implementation only supports I2C and all code is present in a single file stmpe.c.

This patchset separates out code into three files
- stmpe: specific to controller only
- stmpe-i2c: specific to i2c interface
- stmpe-spi: specific to spi interface

In order to rebase it cleanly, please apply earlier floated patch
"mfd/stmpe: Add support for irq over gpio pin"

Viresh Kumar (2):
mfd/stmpe: separate out controller and interface specific code mfd/stmpe: Add support for SPI interface

 drivers/mfd/Kconfig       |   19 ++++++-
 drivers/mfd/Makefile      |    2 +
 drivers/mfd/stmpe-i2c.c   |  116 +++++++++++++++++++++++++++++++++++
 drivers/mfd/stmpe-spi.c   |  147 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/mfd/stmpe.c       |  128 ++++++++++++---------------------------
 drivers/mfd/stmpe.h       |   34 ++++++++++
 include/linux/mfd/stmpe.h |    7 ++-
 7 files changed, 361 insertions(+), 92 deletions(-)
 create mode 100644 drivers/mfd/stmpe-i2c.c
 create mode 100644 drivers/mfd/stmpe-spi.c

1.7.2.2

Few STMPE controller can have register interface over SPI or I2C. Current implementation only supports I2C and all code is present in a single file stmpe.c. It would be better to separate out I2C interface specific code from controller specific code. Later SPI specific code can be added in a separate file.

This patch separates out I2C and controller specific code into separate files, making stmpe.c independent of I2C.

---
 drivers/mfd/Kconfig       |   11 ++++
 drivers/mfd/Makefile      |    1 +
 drivers/mfd/stmpe-i2c.c   |  116 ++++++++++++++++++++++++++++++++++++++++
 drivers/mfd/stmpe.c       |  128 ++++++++++++++-------------------------------
 drivers/mfd/stmpe.h       |   33 ++++++++++++
 include/linux/mfd/stmpe.h |    7 ++-
 6 files changed, 205 insertions(+), 91 deletions(-)
 create mode 100644 drivers/mfd/stmpe-i2c.c

index a67adcb..2f8561a 100644
@@ -293,6 +293,17 @@ config MFD_STMPE
 		Keypad: stmpe-keypad
 		Touchscreen: stmpe-ts
 
+menu "STMPE Interface Drivers"
+depends on MFD_STMPE
+
+config STMPE_I2C
+	bool "STMPE I2C Inteface"
+	depends on I2C
+	default y
+	help
+	  This is used to enable I2C interface of STMPE
+endmenu
+
 config MFD_TC3589X
 	bool "Support Toshiba TC35892 and variants"
 	depends on I2C=y && GENERIC_HARDIRQS

index c580203..24ee9bb 100644
@@ -16,6 +16,7 @@ obj-$(CONFIG_MFD_DM355EVM_MSP)	+= dm355evm_msp.o
 obj-$(CONFIG_MFD_TI_SSP)	+= ti-ssp.o
 
 obj-$(CONFIG_MFD_STMPE)		+= stmpe.o
+obj-$(CONFIG_STMPE_I2C)		+= stmpe-i2c.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

index e4ee3895..c716044 100644
@@ -8,6 +8,14 @@
 #ifndef __STMPE_H
 #define __STMPE_H
 
+#include <linux/device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/stmpe.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+
+extern const struct dev_pm_ops stmpe_dev_pm_ops;
+
 #ifdef STMPE_DUMP_BYTES
 static inline void stmpe_dump_bytes(const char *str, const void *buf,
 				    size_t len)

@@ -67,6 +75,31 @@ struct stmpe_variant_info {
 	int (*enable_autosleep)(struct stmpe *stmpe, int autosleep_timeout);
 };
 
+/**
+ * struct stmpe_client_info - i2c or spi specific routines/info
+ * @data: client specific data
+ * @read_byte: read single byte
+ * @write_byte: write single byte
+ * @read_block: read block or multiple bytes
+ * @write_block: write block or multiple bytes
+ * @init: client init routine, called during probe
+ */
+struct stmpe_client_info {
+	void *data;
+	int irq;
+	void *client;
+	struct device *dev;
+	int (*read_byte)(struct stmpe *stmpe, u8 reg);
+	int (*write_byte)(struct stmpe *stmpe, u8 reg, u8 val);
+	int (*read_block)(struct stmpe *stmpe, u8 reg, u8 len, u8 *values);
+	int (*write_block)(struct stmpe *stmpe, u8 reg, u8 len,
+			const u8 *values);
+	void (*init)(struct stmpe *stmpe);
+};
+
+int stmpe_probe(struct stmpe_client_info *ci);
+int stmpe_remove(struct stmpe *stmpe);
+
 #define STMPE_ICR_LSB_HIGH	(1 << 2)
 #define STMPE_ICR_LSB_EDGE	(1 << 1)
 #define STMPE_ICR_LSB_GIM	(1 << 0)

index 270d661..babc6b2 100644
@@ -50,13 +50,15 @@ enum {
 
 
 struct stmpe_variant_info;
+struct stmpe_client_info;
 
 /**
  * struct stmpe - STMPE MFD structure
  * @lock: lock protecting I/O operations
  * @irq_lock: IRQ bus lock
  * @dev: device, mostly for dev_dbg()
- * @i2c: i2c client
+ * @client: client - i2c or spi
+ * @ci: client specific information
  * @partnum: part number
  * @variant: the detected STMPE model number
  * @regs: list of addresses of registers which are at different addresses on

@@ -72,7 +74,8 @@ struct stmpe {
 	struct mutex lock;
 	struct mutex irq_lock;
 	struct device *dev;
-	struct i2c_client *i2c;
+	void *client;
+	struct stmpe_client_info *ci;
 	enum stmpe_partnum partnum;
 	struct stmpe_variant_info *variant;
 	const u8 *regs;

1.7.2.2

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.

---
 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

index 2f8561a..ebfb296 100644
@@ -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

index 24ee9bb..eac1e9f 100644
@@ -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

index c716044..908f482 100644
@@ -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

Patches look clean and nice to me.

Yours,
Linus Walleij

Could you instead convert stmpe to use the register map API, and then add the SPI interface? Converting to regmap should both simplify the existing code as well as make it possible to add the second interface with fewer lines of code.

Sorry Rabin, but i couldn't get your comment completely. :( Can you please spend few lines on "what do you mean by register map API"?

viresh

drivers/base/regmap, added in b83a313bf25 ("regmap: Add generic non-memory mapped register access API").

Several MFDs are already using it (git grep regmap drivers/mfd/), and patches to convert more are making the rounds on the lists.

Ok. Got it now. :)

Can we get this patchset pushed as it is and i will do this regmap stuff later in a separate patchset? Actually i am a bit busy currently with some other activities and can come back to it after some time.

viresh

Hi Viresh,

Ok, but I really hope you will be able to get back at it. I applied your patchset to my for-next branch for now.

Cheers,
Samuel.

Intel Open Source Technology Centre
http://oss.intel.com/

I will surely like to do it as soon as i get some time.

viresh