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>
105 lines
2.3 KiB
C
105 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Microchip KSZ8795 series register access through SPI
|
|
*
|
|
* Copyright (C) 2017 Microchip Technology Inc.
|
|
* Tristram Ha <Tristram.Ha@microchip.com>
|
|
*/
|
|
|
|
#include <asm/unaligned.h>
|
|
|
|
#include <linux/delay.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/regmap.h>
|
|
#include <linux/spi/spi.h>
|
|
|
|
#include "ksz_common.h"
|
|
|
|
#define SPI_ADDR_SHIFT 12
|
|
#define SPI_ADDR_ALIGN 3
|
|
#define SPI_TURNAROUND_SHIFT 1
|
|
|
|
KSZ_REGMAP_TABLE(ksz8795, 16, SPI_ADDR_SHIFT,
|
|
SPI_TURNAROUND_SHIFT, SPI_ADDR_ALIGN);
|
|
|
|
static int ksz8795_spi_probe(struct spi_device *spi)
|
|
{
|
|
struct regmap_config rc;
|
|
struct ksz_device *dev;
|
|
int i, ret;
|
|
|
|
dev = ksz_switch_alloc(&spi->dev, spi);
|
|
if (!dev)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(ksz8795_regmap_config); i++) {
|
|
rc = ksz8795_regmap_config[i];
|
|
rc.lock_arg = &dev->regmap_mutex;
|
|
dev->regmap[i] = devm_regmap_init_spi(spi, &rc);
|
|
if (IS_ERR(dev->regmap[i])) {
|
|
ret = PTR_ERR(dev->regmap[i]);
|
|
dev_err(&spi->dev,
|
|
"Failed to initialize regmap%i: %d\n",
|
|
ksz8795_regmap_config[i].val_bits, ret);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
if (spi->dev.platform_data)
|
|
dev->pdata = spi->dev.platform_data;
|
|
|
|
ret = ksz8795_switch_register(dev);
|
|
|
|
/* Main DSA driver may not be started yet. */
|
|
if (ret)
|
|
return ret;
|
|
|
|
spi_set_drvdata(spi, dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ksz8795_spi_remove(struct spi_device *spi)
|
|
{
|
|
struct ksz_device *dev = spi_get_drvdata(spi);
|
|
|
|
if (dev)
|
|
ksz_switch_remove(dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void ksz8795_spi_shutdown(struct spi_device *spi)
|
|
{
|
|
struct ksz_device *dev = spi_get_drvdata(spi);
|
|
|
|
if (dev && dev->dev_ops->shutdown)
|
|
dev->dev_ops->shutdown(dev);
|
|
}
|
|
|
|
static const struct of_device_id ksz8795_dt_ids[] = {
|
|
{ .compatible = "microchip,ksz8765" },
|
|
{ .compatible = "microchip,ksz8794" },
|
|
{ .compatible = "microchip,ksz8795" },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, ksz8795_dt_ids);
|
|
|
|
static struct spi_driver ksz8795_spi_driver = {
|
|
.driver = {
|
|
.name = "ksz8795-switch",
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = of_match_ptr(ksz8795_dt_ids),
|
|
},
|
|
.probe = ksz8795_spi_probe,
|
|
.remove = ksz8795_spi_remove,
|
|
.shutdown = ksz8795_spi_shutdown,
|
|
};
|
|
|
|
module_spi_driver(ksz8795_spi_driver);
|
|
|
|
MODULE_AUTHOR("Tristram Ha <Tristram.Ha@microchip.com>");
|
|
MODULE_DESCRIPTION("Microchip KSZ8795 Series Switch SPI Driver");
|
|
MODULE_LICENSE("GPL");
|