mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-14 11:46:46 +07:00
71200fcbb9
Use devm_platform_ioremap_resource() to simplify the code a bit. This is detected by coccinelle. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Link: https://lore.kernel.org/r/20191009144435.12656-1-yuehaibing@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
129 lines
2.7 KiB
C
129 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* sgi_w1.c - w1 master driver for one wire support in SGI ASICs
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/io.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mod_devicetable.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/platform_data/sgi-w1.h>
|
|
|
|
#include <linux/w1.h>
|
|
|
|
#define MCR_RD_DATA BIT(0)
|
|
#define MCR_DONE BIT(1)
|
|
|
|
#define MCR_PACK(pulse, sample) (((pulse) << 10) | ((sample) << 2))
|
|
|
|
struct sgi_w1_device {
|
|
u32 __iomem *mcr;
|
|
struct w1_bus_master bus_master;
|
|
char dev_id[64];
|
|
};
|
|
|
|
static u8 sgi_w1_wait(u32 __iomem *mcr)
|
|
{
|
|
u32 mcr_val;
|
|
|
|
do {
|
|
mcr_val = readl(mcr);
|
|
} while (!(mcr_val & MCR_DONE));
|
|
|
|
return (mcr_val & MCR_RD_DATA) ? 1 : 0;
|
|
}
|
|
|
|
/*
|
|
* this is the low level routine to
|
|
* reset the device on the One Wire interface
|
|
* on the hardware
|
|
*/
|
|
static u8 sgi_w1_reset_bus(void *data)
|
|
{
|
|
struct sgi_w1_device *dev = data;
|
|
u8 ret;
|
|
|
|
writel(MCR_PACK(520, 65), dev->mcr);
|
|
ret = sgi_w1_wait(dev->mcr);
|
|
udelay(500); /* recovery time */
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* this is the low level routine to read/write a bit on the One Wire
|
|
* interface on the hardware. It does write 0 if parameter bit is set
|
|
* to 0, otherwise a write 1/read.
|
|
*/
|
|
static u8 sgi_w1_touch_bit(void *data, u8 bit)
|
|
{
|
|
struct sgi_w1_device *dev = data;
|
|
u8 ret;
|
|
|
|
if (bit)
|
|
writel(MCR_PACK(6, 13), dev->mcr);
|
|
else
|
|
writel(MCR_PACK(80, 30), dev->mcr);
|
|
|
|
ret = sgi_w1_wait(dev->mcr);
|
|
if (bit)
|
|
udelay(100); /* recovery */
|
|
return ret;
|
|
}
|
|
|
|
static int sgi_w1_probe(struct platform_device *pdev)
|
|
{
|
|
struct sgi_w1_device *sdev;
|
|
struct sgi_w1_platform_data *pdata;
|
|
|
|
sdev = devm_kzalloc(&pdev->dev, sizeof(struct sgi_w1_device),
|
|
GFP_KERNEL);
|
|
if (!sdev)
|
|
return -ENOMEM;
|
|
|
|
sdev->mcr = devm_platform_ioremap_resource(pdev, 0);
|
|
if (IS_ERR(sdev->mcr))
|
|
return PTR_ERR(sdev->mcr);
|
|
|
|
sdev->bus_master.data = sdev;
|
|
sdev->bus_master.reset_bus = sgi_w1_reset_bus;
|
|
sdev->bus_master.touch_bit = sgi_w1_touch_bit;
|
|
|
|
pdata = dev_get_platdata(&pdev->dev);
|
|
if (pdata) {
|
|
strlcpy(sdev->dev_id, pdata->dev_id, sizeof(sdev->dev_id));
|
|
sdev->bus_master.dev_id = sdev->dev_id;
|
|
}
|
|
|
|
platform_set_drvdata(pdev, sdev);
|
|
|
|
return w1_add_master_device(&sdev->bus_master);
|
|
}
|
|
|
|
/*
|
|
* disassociate the w1 device from the driver
|
|
*/
|
|
static int sgi_w1_remove(struct platform_device *pdev)
|
|
{
|
|
struct sgi_w1_device *sdev = platform_get_drvdata(pdev);
|
|
|
|
w1_remove_master_device(&sdev->bus_master);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver sgi_w1_driver = {
|
|
.driver = {
|
|
.name = "sgi_w1",
|
|
},
|
|
.probe = sgi_w1_probe,
|
|
.remove = sgi_w1_remove,
|
|
};
|
|
module_platform_driver(sgi_w1_driver);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Thomas Bogendoerfer");
|
|
MODULE_DESCRIPTION("Driver for One-Wire IP in SGI ASICs");
|