mirror of
https://github.com/brain-hackers/linux-brain.git
synced 2024-06-09 23:36:23 +09:00
013572a236
The KSZ driver uses one regmap per register width (8/16/32), each with it's own lock, but accessing the same set of registers. In theory, it is possible to create a race condition between these regmaps, although the underlying bus (SPI or I2C) locking should assure nothing bad will really happen and the accesses would be correct. To make the driver do the right thing, add one single shared mutex for all the regmaps used by the driver instead. This assures that even if some future hardware is on a bus which does not serialize the accesses the same way SPI or I2C does, nothing bad will happen. Note that the status_mutex was unused and only initied, hence it was renamed and repurposed as the regmap mutex. Signed-off-by: Marek Vasut <marex@denx.de> Cc: Andrew Lunn <andrew@lunn.ch> Cc: David S. Miller <davem@davemloft.net> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: George McCollister <george.mccollister@gmail.com> Cc: Tristram Ha <Tristram.Ha@microchip.com> Cc: Woojung Huh <woojung.huh@microchip.com> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
104 lines
2.3 KiB
C
104 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Microchip KSZ9477 series register access through I2C
|
|
*
|
|
* Copyright (C) 2018-2019 Microchip Technology Inc.
|
|
*/
|
|
|
|
#include <linux/i2c.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/regmap.h>
|
|
|
|
#include "ksz_common.h"
|
|
|
|
KSZ_REGMAP_TABLE(ksz9477, not_used, 16, 0, 0);
|
|
|
|
static int ksz9477_i2c_probe(struct i2c_client *i2c,
|
|
const struct i2c_device_id *i2c_id)
|
|
{
|
|
struct regmap_config rc;
|
|
struct ksz_device *dev;
|
|
int i, ret;
|
|
|
|
dev = ksz_switch_alloc(&i2c->dev, i2c);
|
|
if (!dev)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(ksz9477_regmap_config); i++) {
|
|
rc = ksz9477_regmap_config[i];
|
|
rc.lock_arg = &dev->regmap_mutex;
|
|
dev->regmap[i] = devm_regmap_init_i2c(i2c, &rc);
|
|
if (IS_ERR(dev->regmap[i])) {
|
|
ret = PTR_ERR(dev->regmap[i]);
|
|
dev_err(&i2c->dev,
|
|
"Failed to initialize regmap%i: %d\n",
|
|
ksz9477_regmap_config[i].val_bits, ret);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (i2c->dev.platform_data)
|
|
dev->pdata = i2c->dev.platform_data;
|
|
|
|
ret = ksz9477_switch_register(dev);
|
|
|
|
/* Main DSA driver may not be started yet. */
|
|
if (ret)
|
|
return ret;
|
|
|
|
i2c_set_clientdata(i2c, dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ksz9477_i2c_remove(struct i2c_client *i2c)
|
|
{
|
|
struct ksz_device *dev = i2c_get_clientdata(i2c);
|
|
|
|
ksz_switch_remove(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ksz9477_i2c_shutdown(struct i2c_client *i2c)
|
|
{
|
|
struct ksz_device *dev = i2c_get_clientdata(i2c);
|
|
|
|
if (dev && dev->dev_ops->shutdown)
|
|
dev->dev_ops->shutdown(dev);
|
|
}
|
|
|
|
static const struct i2c_device_id ksz9477_i2c_id[] = {
|
|
{ "ksz9477-switch", 0 },
|
|
{},
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(i2c, ksz9477_i2c_id);
|
|
|
|
static const struct of_device_id ksz9477_dt_ids[] = {
|
|
{ .compatible = "microchip,ksz9477" },
|
|
{ .compatible = "microchip,ksz9897" },
|
|
{ .compatible = "microchip,ksz9567" },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ksz9477_dt_ids);
|
|
|
|
static struct i2c_driver ksz9477_i2c_driver = {
|
|
.driver = {
|
|
.name = "ksz9477-switch",
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = of_match_ptr(ksz9477_dt_ids),
|
|
},
|
|
.probe = ksz9477_i2c_probe,
|
|
.remove = ksz9477_i2c_remove,
|
|
.shutdown = ksz9477_i2c_shutdown,
|
|
.id_table = ksz9477_i2c_id,
|
|
};
|
|
|
|
module_i2c_driver(ksz9477_i2c_driver);
|
|
|
|
MODULE_AUTHOR("Tristram Ha <Tristram.Ha@microchip.com>");
|
|
MODULE_DESCRIPTION("Microchip KSZ9477 Series Switch I2C access Driver");
|
|
MODULE_LICENSE("GPL v2");
|