// SPDX-License-Identifier: GPL-2.0-only
/* MCP23S08 SPI GPIO driver */
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include "pinctrl-mcp23s08.h"
#define MCP_MAX_DEV_PER_CS 8
/*
* A given spi_device can represent up to eight mcp23sxx chips
* sharing the same chipselect but using different addresses
* (e.g. chips #0 and #3 might be populated, but not #1 or #2).
* Driver data holds all the per-chip data.
*/
struct mcp23s08_driver_data {
unsigned ngpio;
struct mcp23s08 *mcp[8];
struct mcp23s08 chip[];
};
static int mcp23sxx_spi_write(void *context, const void *data, size_t count)
{
struct mcp23s08 *mcp = context;
struct spi_device *spi = to_spi_device(mcp->dev);
struct spi_message m;
struct spi_transfer t[2] = { { .tx_buf = &mcp->addr, .len = 1, },
{ .tx_buf = data, .len = count, }, };
spi_message_init(&m);
spi_message_add_tail(&t[0], &m);
spi_message_add_tail(&t[1], &m);
return spi_sync(spi, &m);
}
static int mcp23sxx_spi_gather_write(void *context,
const void *reg, size_t reg_size,
const void *val, size_t val_size)
{
struct mcp23s08 *mcp = context;
struct spi_device *spi = to_spi_device(mcp->dev);
struct spi_message m;
struct spi_transfer t[3] = { { .tx_buf = &mcp->addr, .len = 1, },
{ .tx_buf = reg, .len = reg_size, },
{ .tx_buf = val, .len = val_size, }, };
spi_message_init(&m);
spi_message_add_tail(&t[0], &m);
spi_message_add_tail(&t[1], &m);
spi_message_add_tail(&t[2], &m);
return spi_sync(spi, &m);
}
static int mcp23sxx_spi_read(void *context, const void *reg, size_t reg_size,
void *val, size_t val_size)
{
struct mcp23s08 *mcp = context;
struct spi_device *spi = to_spi_device(mcp->dev);
u8 tx[2];
if (reg_size != 1)
return -EINVAL;
tx[0] = mcp->addr | 0x01;
tx[1] = *((u8 *) reg);
return spi_write_then_read(spi, tx, sizeof(tx), val, val_size);
}
static const struct regmap_bus mcp23sxx_spi_regmap = {
.write = mcp23sxx_spi_write,
.gather_write = mcp23sxx_spi_gather_write,
.read = mcp23sxx_spi_read,
};
static int mcp23s08_spi_regmap_init(struct mcp23s08 *mcp, struct device *dev,
unsigned int addr,
const struct mcp23s08_info *info)
{
struct regmap_config *copy;
const char *name;
switch (info->type) {
case MCP_TYPE_S08:
mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s08.%d", addr);
if (!mcp->chip.label)
return -ENOMEM;
name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
if (!name)
return -ENOMEM;
break;
case MCP_TYPE_S17:
mcp->chip.label = devm_kasprintf(dev, GFP_KERNEL, "mcp23s17.%d", addr);
if (!mcp->chip.label)
return -ENOMEM;
name = devm_kasprintf(dev, GFP_KERNEL, "%d", addr);
if (!name)
return -ENOMEM;
break;
case MCP_TYPE_S18:
mcp->chip.label = info->label;
name = info->regmap->name;
break;
default:
dev_err(dev, "invalid device type (%d)\n", info->type);
return -EINVAL;
}
mcp->reg_shift = info->reg_shift;
mcp->chip.ngpio = info->ngpio;
copy = devm_kmemdup(dev, info->regmap, sizeof(*info->regmap), GFP_KERNEL);
if (!copy)
return -ENOMEM;
copy->name = name;
mcp->regmap = devm_regmap_init(dev, &mcp23sxx_spi_regmap, mcp, copy);
if (IS_ERR(mcp->regmap))
dev_err(dev, "regmap init failed for %s\n", mcp->chip.label);
return PTR_ERR_OR_ZERO(mcp->regmap);
}
static int mcp23s08_probe(struct spi_device *spi)
{
struct mcp23s08_driver_data *data;
const struct mcp23s08_info *info;
struct device *dev = &spi->dev;
unsigned long spi_present_mask;
unsigned int ngpio = 0;
unsigned int addr;
int chips;
int ret;
u32 v;
info = spi_get_device_match_data(spi);
ret = device_property_read_u32(dev, "microchip,spi-present-mask", &v);
if (ret) {
ret = device_property_read_u32(dev, "mcp,spi-present-mask", &v);
if (ret) {
dev_err(dev, "missing spi-present-mask");
return ret;
}
}
spi_present_mask = v;
if (!spi_present_mask || spi_present_mask >= BIT(MCP_MAX_DEV_PER_CS)) {
dev_err(dev, "invalid spi-present-mask");
return -ENODEV;
}
chips = hweight_long(spi_present_mask);
data = devm_kzalloc(dev, struct_size(data, chip, chips), GFP_KERNEL);
if (!data)
return -ENOMEM;
spi_set_drvdata(spi, data);
for_each_set_bit(addr, &spi_present_mask, MCP_MAX_DEV_PER_CS) {
data->mcp[addr] = &data->chip[--chips];
data->mcp[addr]->irq = spi->irq;
ret = mcp23s08_spi_regmap_init(data->mcp[addr], dev, addr, info);
if (ret)
return ret;
data->mcp[addr]->pinctrl_desc.name = devm_kasprintf(dev, GFP_KERNEL,
"mcp23xxx-pinctrl.%d",
addr);
if (!data->mcp[addr]->pinctrl_desc.name)
return -ENOMEM;
ret = mcp23s08_probe_one(data->mcp[addr], dev, 0x40 | (addr << 1),
info->type, -1);
if (ret < 0)
return ret;
ngpio += data->mcp[addr]->chip.ngpio;
}
data->ngpio = ngpio;
return 0;
}
static const struct mcp23s08_info mcp23s08_spi = {
.regmap = &mcp23x08_regmap,
.type = MCP_TYPE_S08,
.ngpio = 8,
.reg_shift = 0,
};
static const struct mcp23s08_info mcp23s17_spi = {
.regmap = &mcp23x17_regmap,
.type = MCP_TYPE_S17,
.ngpio = 16,
.reg_shift = 1,
};
static const struct mcp23s08_info mcp23s18_spi = {
.regmap = &mcp23x17_regmap,
.label = "mcp23s18",
.type = MCP_TYPE_S18,
.ngpio = 16,
.reg_shift = 1,
};
static const struct spi_device_id mcp23s08_ids[] = {
{ "mcp23s08", (kernel_ulong_t)&mcp23s08_spi },
{ "mcp23s17", (kernel_ulong_t)&mcp23s17_spi },
{ "mcp23s18", (kernel_ulong_t)&mcp23s18_spi },
{ }
};
MODULE_DEVICE_TABLE(spi, mcp23s08_ids);
static const struct of_device_id mcp23s08_spi_of_match[] = {
{ .compatible = "microchip,mcp23s08", .data = &mcp23s08_spi },
{ .compatible = "microchip,mcp23s17", .data = &mcp23s17_spi },
{ .compatible = "microchip,mcp23s18", .data = &mcp23s18_spi },
/* NOTE: The use of the mcp prefix is deprecated and will be removed. */
{ .compatible = "mcp,mcp23s08", .data = &mcp23s08_spi },
{ .compatible = "mcp,mcp23s17", .data = &mcp23s17_spi },
{ }
};
MODULE_DEVICE_TABLE(of, mcp23s08_spi_of_match);
static struct spi_driver mcp23s08_driver = {
.probe = mcp23s08_probe,
.id_table = mcp23s08_ids,
.driver = {
.name = "mcp23s08",
.of_match_table = mcp23s08_spi_of_match,
},
};
static int __init mcp23s08_spi_init(void)
{
return spi_register_driver(&mcp23s08_driver);
}
/*
* Register after SPI postcore initcall and before
* subsys initcalls that may rely on these GPIOs.
*/
subsys_initcall(mcp23s08_spi_init);
static void mcp23s08_spi_exit(void)
{
spi_unregister_driver(&mcp23s08_driver);
}
module_exit(mcp23s08_spi_exit);
MODULE_DESCRIPTION("MCP23S08 SPI GPIO driver");
MODULE_LICENSE("GPL");
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