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Commit 7326e38f authored by Ganesan Ramalingam's avatar Ganesan Ramalingam Committed by Wolfram Sang
Browse files

i2c: i2c-ocores: support for 16bit and 32bit IO 



Some architectures supports only 16-bit or 32-bit read/write access to
their IO space. Add a 'reg-io-width' platform and OF parameter which
specifies the IO width to support these platforms.

reg-io-width can be specified as 1, 2 or 4, and has a default value
of 1 if it is unspecified.

Signed-off-by: default avatarGanesan Ramalingam <ganesanr@broadcom.com>
Signed-off-by: default avatarJayachandran C <jayachandranc@netlogicmicro.com>
Signed-off-by: default avatarWolfram Sang <w.sang@pengutronix.de>
parent d739a464

Documentation/devicetree/bindings/i2c/i2c-ocores.txt

+2 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ Required properties: 


Optional properties:

- reg-shift       : device register offsets are shifted by this value

- reg-io-width    : io register width in bytes (1, 2 or 4)

- regstep         : deprecated, use reg-shift above



Example:
@@ -23,6 +24,7 @@ Example: 
		clock-frequency = <20000000>;



		reg-shift = <0>;	/* 8 bit registers */

		reg-io-width = <1>;	/* 8 bit read/write */



		dummy@60 {

			compatible = "dummy";

drivers/i2c/busses/i2c-ocores.c

+19 −2
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
struct ocores_i2c {

	void __iomem *base;

	u32 reg_shift;

	u32 reg_io_width;

	wait_queue_head_t wait;

	struct i2c_adapter adap;

	struct i2c_msg *msg;
@@ -72,11 +73,21 @@ struct ocores_i2c { 


static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)

{

	if (i2c->reg_io_width == 4)

		iowrite32(value, i2c->base + (reg << i2c->reg_shift));

	else if (i2c->reg_io_width == 2)

		iowrite16(value, i2c->base + (reg << i2c->reg_shift));

	else

		iowrite8(value, i2c->base + (reg << i2c->reg_shift));

}



static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)

{

	if (i2c->reg_io_width == 4)

		return ioread32(i2c->base + (reg << i2c->reg_shift));

	else if (i2c->reg_io_width == 2)

		return ioread16(i2c->base + (reg << i2c->reg_shift));

	else

		return ioread8(i2c->base + (reg << i2c->reg_shift));

}
@@ -244,6 +255,8 @@ static int ocores_i2c_of_probe(struct platform_device *pdev, 
	}

	i2c->clock_khz = val / 1000;



	of_property_read_u32(pdev->dev.of_node, "reg-io-width",

				&i2c->reg_io_width);

	return 0;

}

#else
@@ -286,6 +299,7 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev) 
	pdata = pdev->dev.platform_data;

	if (pdata) {

		i2c->reg_shift = pdata->reg_shift;

		i2c->reg_io_width = pdata->reg_io_width;

		i2c->clock_khz = pdata->clock_khz;

	} else {

		ret = ocores_i2c_of_probe(pdev, i2c);
@@ -293,6 +307,9 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev) 
			return ret;

	}



	if (i2c->reg_io_width == 0)

		i2c->reg_io_width = 1; /* Set to default value */



	ocores_init(i2c);



	init_waitqueue_head(&i2c->wait);

include/linux/i2c-ocores.h

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 


struct ocores_i2c_platform_data {

	u32 reg_shift; /* register offset shift value */

	u32 reg_io_width; /* register io read/write width */

	u32 clock_khz; /* input clock in kHz */

	u8 num_devices; /* number of devices in the devices list */

	struct i2c_board_info const *devices; /* devices connected to the bus */