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w1: ds1wm: fix register offset (bus shift) calculation

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Replace incorrect register offsett calculation by
direct configuration of bus_shift in mfd-cell.

Indirect definition of address-shift by resource size
was unobvious and was wrong (should have used a binary log).

Signed-off-by: Johannes Poehlmann <johannes.poehlmann@izt-labs.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johannes Poehlmann
2017-07-25 13:27:11 +02:00
committed by Greg Kroah-Hartman
parent d7b3cf892a
commit 242b476f82
2 changed files with 36 additions and 11 deletions
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23
drivers/w1/masters/ds1wm.c
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@@ -95,7 +95,7 @@ static struct {
struct ds1wm_data {
void __iomem *map;
int bus_shift; /* # of shifts to calc register offsets */
unsigned int bus_shift; /* # of shifts to calc register offsets */
struct platform_device *pdev;
const struct mfd_cell *cell;
int irq;
@@ -473,9 +473,6 @@ static int ds1wm_probe(struct platform_device *pdev)
if (!ds1wm_data->map)
return -ENOMEM;
/* calculate bus shift from mem resource */
ds1wm_data->bus_shift = resource_size(res) >> 3;
ds1wm_data->pdev = pdev;
ds1wm_data->cell = mfd_get_cell(pdev);
if (!ds1wm_data->cell)
@@ -484,6 +481,24 @@ static int ds1wm_probe(struct platform_device *pdev)
if (!plat)
return -ENODEV;
/* how many bits to shift register number to get register offset */
if (plat->bus_shift > 2) {
dev_err(&ds1wm_data->pdev->dev,
"illegal bus shift %d, not written",
ds1wm_data->bus_shift);
return -EINVAL;
}
ds1wm_data->bus_shift = plat->bus_shift;
/* make sure resource has space for 8 registers */
if ((8 << ds1wm_data->bus_shift) > resource_size(res)) {
dev_err(&ds1wm_data->pdev->dev,
"memory resource size %d to small, should be %d\n",
(int)resource_size(res),
8 << ds1wm_data->bus_shift);
return -EINVAL;
}
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res)
return -ENXIO;