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Commit baa8055d authored by Johannes Poehlmann's avatar Johannes Poehlmann Committed by Greg Kroah-Hartman
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w1: ds1wm: make endian clean and use standard io memory accessors 



o Make endian clean, make HW-endianness configurable.

o Use ioread*, iowrite* instead of __raw_readb,__raw_writeb
  to also use memory-barriers when accessing HW-registers.
  We do not want reordering to happen here.

Both changes are tightly coupled, so I do them in one patch

Signed-off-by: default avatarJohannes Poehlmann <johannes.poehlmann@izt-labs.de>
Acked-by: default avatarEvgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 242b476f

drivers/w1/masters/ds1wm.c

+58 −2
Original line number Diff line number Diff line
@@ -96,6 +96,7 @@ static struct { 
struct ds1wm_data {

	void     __iomem *map;

	unsigned int      bus_shift; /* # of shifts to calc register offsets */

	bool      is_hw_big_endian;

	struct platform_device *pdev;

	const struct mfd_cell   *cell;

	int      irq;
@@ -115,12 +116,65 @@ struct ds1wm_data { 
static inline void ds1wm_write_register(struct ds1wm_data *ds1wm_data, u32 reg,

					u8 val)

{

	__raw_writeb(val, ds1wm_data->map + (reg << ds1wm_data->bus_shift));

	if (ds1wm_data->is_hw_big_endian) {

		switch (ds1wm_data->bus_shift) {

		case 0:

			iowrite8(val, ds1wm_data->map + (reg << 0));

			break;

		case 1:

			iowrite16be((u16)val, ds1wm_data->map + (reg << 1));

			break;

		case 2:

			iowrite32be((u32)val, ds1wm_data->map + (reg << 2));

			break;

		}

	} else {

		switch (ds1wm_data->bus_shift) {

		case 0:

			iowrite8(val, ds1wm_data->map + (reg << 0));

			break;

		case 1:

			iowrite16((u16)val, ds1wm_data->map + (reg << 1));

			break;

		case 2:

			iowrite32((u32)val, ds1wm_data->map + (reg << 2));

			break;

		}

	}

}



static inline u8 ds1wm_read_register(struct ds1wm_data *ds1wm_data, u32 reg)

{

	return __raw_readb(ds1wm_data->map + (reg << ds1wm_data->bus_shift));

	u32 val = 0;



	if (ds1wm_data->is_hw_big_endian) {

		switch (ds1wm_data->bus_shift) {

		case 0:

			val = ioread8(ds1wm_data->map + (reg << 0));

			break;

		case 1:

			val = ioread16be(ds1wm_data->map + (reg << 1));

			break;

		case 2:

			val = ioread32be(ds1wm_data->map + (reg << 2));

			break;

		}

	} else {

		switch (ds1wm_data->bus_shift) {

		case 0:

			val = ioread8(ds1wm_data->map + (reg << 0));

			break;

		case 1:

			val = ioread16(ds1wm_data->map + (reg << 1));

			break;

		case 2:

			val = ioread32(ds1wm_data->map + (reg << 2));

			break;

		}

	}

	dev_dbg(&ds1wm_data->pdev->dev,

		"ds1wm_read_register reg: %d, 32 bit val:%x\n", reg, val);

	return (u8)val;

}
@@ -499,6 +553,8 @@ static int ds1wm_probe(struct platform_device *pdev) 
		return -EINVAL;

	}



	ds1wm_data->is_hw_big_endian = plat->is_hw_big_endian;



	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);

	if (!res)

		return -ENXIO;

include/linux/mfd/ds1wm.h

+5 −0
Original line number Diff line number Diff line
@@ -16,6 +16,11 @@ struct ds1wm_driver_data { 
	 */

	unsigned int reset_recover_delay;



	/* Say 1 here for big endian Hardware

	 * (only relevant with bus-shift > 0

	 */

	bool is_hw_big_endian;



	/* left shift of register number to get register address offsett.

	 * Only 0,1,2 allowed for 8,16 or 32 bit bus width respectively

	 */