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gpio: mcp23s08 to support both device tree and platform data
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Device tree is not enabled in some architecture where gpio
driver mcp23s08 is still required.

v2-changes:
- Parse device tree properties into platform data other than
  individual variables.
v3-changes:
- Use of_node in gpio_chip device structure, because the
  struct device * always has an of_node which is NULL when
  OF is not used.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Sonic Zhang authored and Linus Walleij committed Sep 4, 2014
1 parent 59e2211 commit 3af0dbd
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Showing 3 changed files with 52 additions and 31 deletions.
1 change: 0 additions & 1 deletion drivers/gpio/Kconfig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -806,7 +806,6 @@ config GPIO_MAX7301

config GPIO_MCP23S08
tristate "Microchip MCP23xxx I/O expander"
depends on OF_GPIO
depends on (SPI_MASTER && !I2C) || I2C
help
SPI/I2C driver for Microchip MCP23S08/MCP23S17/MCP23008/MCP23017
Expand Down
64 changes: 34 additions & 30 deletions drivers/gpio/gpio-mcp23s08.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -479,7 +479,7 @@ static int mcp23s08_irq_setup(struct mcp23s08 *mcp)

mutex_init(&mcp->irq_lock);

mcp->irq_domain = irq_domain_add_linear(chip->of_node, chip->ngpio,
mcp->irq_domain = irq_domain_add_linear(chip->dev->of_node, chip->ngpio,
&irq_domain_simple_ops, mcp);
if (!mcp->irq_domain)
return -ENODEV;
Expand Down Expand Up @@ -581,7 +581,7 @@ static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)

static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
void *data, unsigned addr, unsigned type,
unsigned base, unsigned pullups)
struct mcp23s08_platform_data *pdata, int cs)
{
int status;
bool mirror = false;
Expand Down Expand Up @@ -635,7 +635,7 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
return -EINVAL;
}

mcp->chip.base = base;
mcp->chip.base = pdata->base;
mcp->chip.can_sleep = true;
mcp->chip.dev = dev;
mcp->chip.owner = THIS_MODULE;
Expand All @@ -648,11 +648,9 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
if (status < 0)
goto fail;

mcp->irq_controller = of_property_read_bool(mcp->chip.of_node,
"interrupt-controller");
mcp->irq_controller = pdata->irq_controller;
if (mcp->irq && mcp->irq_controller && (type == MCP_TYPE_017))
mirror = of_property_read_bool(mcp->chip.of_node,
"microchip,irq-mirror");
mirror = pdata->mirror;

if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror) {
/* mcp23s17 has IOCON twice, make sure they are in sync */
Expand All @@ -668,7 +666,7 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
}

/* configure ~100K pullups */
status = mcp->ops->write(mcp, MCP_GPPU, pullups);
status = mcp->ops->write(mcp, MCP_GPPU, pdata->chip[cs].pullups);
if (status < 0)
goto fail;

Expand Down Expand Up @@ -768,25 +766,29 @@ MODULE_DEVICE_TABLE(of, mcp23s08_i2c_of_match);
static int mcp230xx_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct mcp23s08_platform_data *pdata;
struct mcp23s08_platform_data *pdata, local_pdata;
struct mcp23s08 *mcp;
int status, base, pullups;
int status;
const struct of_device_id *match;

match = of_match_device(of_match_ptr(mcp23s08_i2c_of_match),
&client->dev);
pdata = dev_get_platdata(&client->dev);
if (match || !pdata) {
base = -1;
pullups = 0;
if (match) {
pdata = &local_pdata;
pdata->base = -1;
pdata->chip[0].pullups = 0;
pdata->irq_controller = of_property_read_bool(
client->dev.of_node,
"interrupt-controller");
pdata->mirror = of_property_read_bool(client->dev.of_node,
"microchip,irq-mirror");
client->irq = irq_of_parse_and_map(client->dev.of_node, 0);
} else {
if (!gpio_is_valid(pdata->base)) {
pdata = dev_get_platdata(&client->dev);
if (!pdata || !gpio_is_valid(pdata->base)) {
dev_dbg(&client->dev, "invalid platform data\n");
return -EINVAL;
}
base = pdata->base;
pullups = pdata->chip[0].pullups;
}

mcp = kzalloc(sizeof(*mcp), GFP_KERNEL);
Expand All @@ -795,7 +797,7 @@ static int mcp230xx_probe(struct i2c_client *client,

mcp->irq = client->irq;
status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
id->driver_data, base, pullups);
id->driver_data, pdata, 0);
if (status)
goto fail;

Expand Down Expand Up @@ -863,14 +865,12 @@ static void mcp23s08_i2c_exit(void) { }

static int mcp23s08_probe(struct spi_device *spi)
{
struct mcp23s08_platform_data *pdata;
struct mcp23s08_platform_data *pdata, local_pdata;
unsigned addr;
int chips = 0;
struct mcp23s08_driver_data *data;
int status, type;
unsigned base = -1,
ngpio = 0,
pullups[ARRAY_SIZE(pdata->chip)];
unsigned ngpio = 0;
const struct of_device_id *match;
u32 spi_present_mask = 0;

Expand All @@ -893,11 +893,18 @@ static int mcp23s08_probe(struct spi_device *spi)
return -ENODEV;
}

pdata = &local_pdata;
pdata->base = -1;
for (addr = 0; addr < ARRAY_SIZE(pdata->chip); addr++) {
pullups[addr] = 0;
pdata->chip[addr].pullups = 0;
if (spi_present_mask & (1 << addr))
chips++;
}
pdata->irq_controller = of_property_read_bool(
spi->dev.of_node,
"interrupt-controller");
pdata->mirror = of_property_read_bool(spi->dev.of_node,
"microchip,irq-mirror");
} else {
type = spi_get_device_id(spi)->driver_data;
pdata = dev_get_platdata(&spi->dev);
Expand All @@ -917,10 +924,7 @@ static int mcp23s08_probe(struct spi_device *spi)
return -EINVAL;
}
spi_present_mask |= 1 << addr;
pullups[addr] = pdata->chip[addr].pullups;
}

base = pdata->base;
}

if (!chips)
Expand All @@ -938,13 +942,13 @@ static int mcp23s08_probe(struct spi_device *spi)
chips--;
data->mcp[addr] = &data->chip[chips];
status = mcp23s08_probe_one(data->mcp[addr], &spi->dev, spi,
0x40 | (addr << 1), type, base,
pullups[addr]);
0x40 | (addr << 1), type, pdata,
addr);
if (status < 0)
goto fail;

if (base != -1)
base += (type == MCP_TYPE_S17) ? 16 : 8;
if (pdata->base != -1)
pdata->base += (type == MCP_TYPE_S17) ? 16 : 8;
ngpio += (type == MCP_TYPE_S17) ? 16 : 8;
}
data->ngpio = ngpio;
Expand Down
18 changes: 18 additions & 0 deletions include/linux/spi/mcp23s08.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,4 +22,22 @@ struct mcp23s08_platform_data {
* base to base+15 (or base+31 for s17 variant).
*/
unsigned base;
/* Marks the device as a interrupt controller.
* NOTE: The interrupt functionality is only supported for i2c
* versions of the chips. The spi chips can also do the interrupts,
* but this is not supported by the linux driver yet.
*/
bool irq_controller;

/* Sets the mirror flag in the IOCON register. Devices
* with two interrupt outputs (these are the devices ending with 17 and
* those that have 16 IOs) have two IO banks: IO 0-7 form bank 1 and
* IO 8-15 are bank 2. These chips have two different interrupt outputs:
* One for bank 1 and another for bank 2. If irq-mirror is set, both
* interrupts are generated regardless of the bank that an input change
* occurred on. If it is not set, the interrupt are only generated for
* the bank they belong to.
* On devices with only one interrupt output this property is useless.
*/
bool mirror;
};

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