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mcp23s08: isolate spi specific parts
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Change spi member of struct mcp23s08 to be a ops-specific opaque data
pointer, and move spi specific knowledge out of mcp23s08_probe_one().

No functional change, but is needed to add i2c support.

Signed-off-by: Peter Korsgaard <[email protected]>
Signed-off-by: Grant Likely <[email protected]>
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@jacmet @glikely
jacmet authored and glikely committed Jul 15, 2011
1 parent 1bb6f9b commit d62b98f
Showing 1 changed file with 57 additions and 24 deletions.
81 changes: 57 additions & 24 deletions drivers/gpio/gpio-mcp23s08.c
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Original file line number Diff line number Diff line change
Expand Up @@ -50,7 +50,6 @@ struct mcp23s08_ops {
};

struct mcp23s08 {
struct spi_device *spi;
u8 addr;

u16 cache[11];
Expand All @@ -60,6 +59,7 @@ struct mcp23s08 {
struct gpio_chip chip;

const struct mcp23s08_ops *ops;
void *data; /* ops specific data */
};

/* A given spi_device can represent up to eight mcp23sxx chips
Expand All @@ -73,14 +73,16 @@ struct mcp23s08_driver_data {
struct mcp23s08 chip[];
};

#ifdef CONFIG_SPI_MASTER

static int mcp23s08_read(struct mcp23s08 *mcp, unsigned reg)
{
u8 tx[2], rx[1];
int status;

tx[0] = mcp->addr | 0x01;
tx[1] = reg;
status = spi_write_then_read(mcp->spi, tx, sizeof tx, rx, sizeof rx);
status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
return (status < 0) ? status : rx[0];
}

Expand All @@ -91,7 +93,7 @@ static int mcp23s08_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
tx[0] = mcp->addr;
tx[1] = reg;
tx[2] = val;
return spi_write_then_read(mcp->spi, tx, sizeof tx, NULL, 0);
return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
}

static int
Expand All @@ -106,7 +108,7 @@ mcp23s08_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
tx[1] = reg;

tmp = (u8 *)vals;
status = spi_write_then_read(mcp->spi, tx, sizeof tx, tmp, n);
status = spi_write_then_read(mcp->data, tx, sizeof tx, tmp, n);
if (status >= 0) {
while (n--)
vals[n] = tmp[n]; /* expand to 16bit */
Expand All @@ -121,7 +123,7 @@ static int mcp23s17_read(struct mcp23s08 *mcp, unsigned reg)

tx[0] = mcp->addr | 0x01;
tx[1] = reg << 1;
status = spi_write_then_read(mcp->spi, tx, sizeof tx, rx, sizeof rx);
status = spi_write_then_read(mcp->data, tx, sizeof tx, rx, sizeof rx);
return (status < 0) ? status : (rx[0] | (rx[1] << 8));
}

Expand All @@ -133,7 +135,7 @@ static int mcp23s17_write(struct mcp23s08 *mcp, unsigned reg, unsigned val)
tx[1] = reg << 1;
tx[2] = val;
tx[3] = val >> 8;
return spi_write_then_read(mcp->spi, tx, sizeof tx, NULL, 0);
return spi_write_then_read(mcp->data, tx, sizeof tx, NULL, 0);
}

static int
Expand All @@ -147,7 +149,7 @@ mcp23s17_read_regs(struct mcp23s08 *mcp, unsigned reg, u16 *vals, unsigned n)
tx[0] = mcp->addr | 0x01;
tx[1] = reg << 1;

status = spi_write_then_read(mcp->spi, tx, sizeof tx,
status = spi_write_then_read(mcp->data, tx, sizeof tx,
(u8 *)vals, n * 2);
if (status >= 0) {
while (n--)
Expand All @@ -169,6 +171,7 @@ static const struct mcp23s08_ops mcp23s17_ops = {
.read_regs = mcp23s17_read_regs,
};

#endif /* CONFIG_SPI_MASTER */

/*----------------------------------------------------------------------*/

Expand Down Expand Up @@ -296,36 +299,46 @@ static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)

/*----------------------------------------------------------------------*/

static int mcp23s08_probe_one(struct spi_device *spi, unsigned addr,
static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
void *data, unsigned addr,
unsigned type, unsigned base, unsigned pullups)
{
struct mcp23s08_driver_data *data = spi_get_drvdata(spi);
struct mcp23s08 *mcp = data->mcp[addr];
int status;
int status;

mutex_init(&mcp->lock);

mcp->spi = spi;
mcp->addr = 0x40 | (addr << 1);
mcp->data = data;
mcp->addr = addr;

mcp->chip.direction_input = mcp23s08_direction_input;
mcp->chip.get = mcp23s08_get;
mcp->chip.direction_output = mcp23s08_direction_output;
mcp->chip.set = mcp23s08_set;
mcp->chip.dbg_show = mcp23s08_dbg_show;

if (type == MCP_TYPE_S17) {
mcp->ops = &mcp23s17_ops;
mcp->chip.ngpio = 16;
mcp->chip.label = "mcp23s17";
} else {
switch (type) {
#ifdef CONFIG_SPI_MASTER
case MCP_TYPE_S08:
mcp->ops = &mcp23s08_ops;
mcp->chip.ngpio = 8;
mcp->chip.label = "mcp23s08";
break;

case MCP_TYPE_S17:
mcp->ops = &mcp23s17_ops;
mcp->chip.ngpio = 16;
mcp->chip.label = "mcp23s17";
break;
#endif /* CONFIG_SPI_MASTER */

default:
dev_err(dev, "invalid device type (%d)\n", type);
return -EINVAL;
}

mcp->chip.base = base;
mcp->chip.can_sleep = 1;
mcp->chip.dev = &spi->dev;
mcp->chip.dev = dev;
mcp->chip.owner = THIS_MODULE;

/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
Expand Down Expand Up @@ -371,11 +384,13 @@ static int mcp23s08_probe_one(struct spi_device *spi, unsigned addr,
status = gpiochip_add(&mcp->chip);
fail:
if (status < 0)
dev_dbg(&spi->dev, "can't setup chip %d, --> %d\n",
addr, status);
dev_dbg(dev, "can't setup chip %d, --> %d\n",
addr, status);
return status;
}

#ifdef CONFIG_SPI_MASTER

static int mcp23s08_probe(struct spi_device *spi)
{
struct mcp23s08_platform_data *pdata;
Expand Down Expand Up @@ -418,7 +433,8 @@ static int mcp23s08_probe(struct spi_device *spi)
continue;
chips--;
data->mcp[addr] = &data->chip[chips];
status = mcp23s08_probe_one(spi, addr, type, base,
status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
0x40 | (addr << 1), type, base,
pdata->chip[addr].pullups);
if (status < 0)
goto fail;
Expand Down Expand Up @@ -488,11 +504,28 @@ static struct spi_driver mcp23s08_driver = {
},
};

static int __init mcp23s08_spi_init(void)
{
return spi_register_driver(&mcp23s08_driver);
}

static void mcp23s08_spi_exit(void)
{
spi_unregister_driver(&mcp23s08_driver);
}

#else

static int __init mcp23s08_spi_init(void) { return 0; }
static void mcp23s08_spi_exit(void) { }

#endif /* CONFIG_SPI_MASTER */

/*----------------------------------------------------------------------*/

static int __init mcp23s08_init(void)
{
return spi_register_driver(&mcp23s08_driver);
return mcp23s08_spi_init();
}
/* register after spi postcore initcall and before
* subsys initcalls that may rely on these GPIOs
Expand All @@ -501,7 +534,7 @@ subsys_initcall(mcp23s08_init);

static void __exit mcp23s08_exit(void)
{
spi_unregister_driver(&mcp23s08_driver);
mcp23s08_spi_exit();
}
module_exit(mcp23s08_exit);

Expand Down

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