mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-15 08:44:14 +08:00
900ed72c8a
The devm_kzalloc() function returns NULL on error, it doesn't return
error pointers.
Fixes: 86559400b3 ("rtc: gamecube: Add a RTC driver for the GameCube, Wii and Wii U")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220107073340.GF22086@kili
378 lines
10 KiB
C
378 lines
10 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
||
/*
|
||
* Nintendo GameCube, Wii and Wii U RTC driver
|
||
*
|
||
* This driver is for the MX23L4005, more specifically its real-time clock and
|
||
* SRAM storage. The value returned by the RTC counter must be added with the
|
||
* offset stored in a bias register in SRAM (on the GameCube and Wii) or in
|
||
* /config/rtc.xml (on the Wii U). The latter being very impractical to access
|
||
* from Linux, this driver assumes the bootloader has read it and stored it in
|
||
* SRAM like for the other two consoles.
|
||
*
|
||
* This device sits on a bus named EXI (which is similar to SPI), channel 0,
|
||
* device 1. This driver assumes no other user of the EXI bus, which is
|
||
* currently the case but would have to be reworked to add support for other
|
||
* GameCube hardware exposed on this bus.
|
||
*
|
||
* References:
|
||
* - https://wiiubrew.org/wiki/Hardware/RTC
|
||
* - https://wiibrew.org/wiki/MX23L4005
|
||
*
|
||
* Copyright (C) 2018 rw-r-r-0644
|
||
* Copyright (C) 2021 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
|
||
*
|
||
* Based on rtc-gcn.c
|
||
* Copyright (C) 2004-2009 The GameCube Linux Team
|
||
* Copyright (C) 2005,2008,2009 Albert Herranz
|
||
* Based on gamecube_time.c from Torben Nielsen.
|
||
*/
|
||
|
||
#include <linux/init.h>
|
||
#include <linux/module.h>
|
||
#include <linux/of.h>
|
||
#include <linux/of_address.h>
|
||
#include <linux/platform_device.h>
|
||
#include <linux/regmap.h>
|
||
#include <linux/rtc.h>
|
||
#include <linux/time.h>
|
||
|
||
/* EXI registers */
|
||
#define EXICSR 0
|
||
#define EXICR 12
|
||
#define EXIDATA 16
|
||
|
||
/* EXI register values */
|
||
#define EXICSR_DEV 0x380
|
||
#define EXICSR_DEV1 0x100
|
||
#define EXICSR_CLK 0x070
|
||
#define EXICSR_CLK_1MHZ 0x000
|
||
#define EXICSR_CLK_2MHZ 0x010
|
||
#define EXICSR_CLK_4MHZ 0x020
|
||
#define EXICSR_CLK_8MHZ 0x030
|
||
#define EXICSR_CLK_16MHZ 0x040
|
||
#define EXICSR_CLK_32MHZ 0x050
|
||
#define EXICSR_INT 0x008
|
||
#define EXICSR_INTSET 0x008
|
||
|
||
#define EXICR_TSTART 0x001
|
||
#define EXICR_TRSMODE 0x002
|
||
#define EXICR_TRSMODE_IMM 0x000
|
||
#define EXICR_TRSTYPE 0x00C
|
||
#define EXICR_TRSTYPE_R 0x000
|
||
#define EXICR_TRSTYPE_W 0x004
|
||
#define EXICR_TLEN 0x030
|
||
#define EXICR_TLEN32 0x030
|
||
|
||
/* EXI registers values to access the RTC */
|
||
#define RTC_EXICSR (EXICSR_DEV1 | EXICSR_CLK_8MHZ | EXICSR_INTSET)
|
||
#define RTC_EXICR_W (EXICR_TSTART | EXICR_TRSMODE_IMM | EXICR_TRSTYPE_W | EXICR_TLEN32)
|
||
#define RTC_EXICR_R (EXICR_TSTART | EXICR_TRSMODE_IMM | EXICR_TRSTYPE_R | EXICR_TLEN32)
|
||
#define RTC_EXIDATA_W 0x80000000
|
||
|
||
/* RTC registers */
|
||
#define RTC_COUNTER 0x200000
|
||
#define RTC_SRAM 0x200001
|
||
#define RTC_SRAM_BIAS 0x200004
|
||
#define RTC_SNAPSHOT 0x204000
|
||
#define RTC_ONTMR 0x210000
|
||
#define RTC_OFFTMR 0x210001
|
||
#define RTC_TEST0 0x210004
|
||
#define RTC_TEST1 0x210005
|
||
#define RTC_TEST2 0x210006
|
||
#define RTC_TEST3 0x210007
|
||
#define RTC_CONTROL0 0x21000c
|
||
#define RTC_CONTROL1 0x21000d
|
||
|
||
/* RTC flags */
|
||
#define RTC_CONTROL0_UNSTABLE_POWER 0x00000800
|
||
#define RTC_CONTROL0_LOW_BATTERY 0x00000200
|
||
|
||
struct priv {
|
||
struct regmap *regmap;
|
||
void __iomem *iob;
|
||
u32 rtc_bias;
|
||
};
|
||
|
||
static int exi_read(void *context, u32 reg, u32 *data)
|
||
{
|
||
struct priv *d = (struct priv *)context;
|
||
void __iomem *iob = d->iob;
|
||
|
||
/* The spin loops here loop about 15~16 times each, so there is no need
|
||
* to use a more expensive sleep method.
|
||
*/
|
||
|
||
/* Write register offset */
|
||
iowrite32be(RTC_EXICSR, iob + EXICSR);
|
||
iowrite32be(reg << 8, iob + EXIDATA);
|
||
iowrite32be(RTC_EXICR_W, iob + EXICR);
|
||
while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
|
||
cpu_relax();
|
||
|
||
/* Read data */
|
||
iowrite32be(RTC_EXICSR, iob + EXICSR);
|
||
iowrite32be(RTC_EXICR_R, iob + EXICR);
|
||
while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
|
||
cpu_relax();
|
||
*data = ioread32be(iob + EXIDATA);
|
||
|
||
/* Clear channel parameters */
|
||
iowrite32be(0, iob + EXICSR);
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int exi_write(void *context, u32 reg, u32 data)
|
||
{
|
||
struct priv *d = (struct priv *)context;
|
||
void __iomem *iob = d->iob;
|
||
|
||
/* The spin loops here loop about 15~16 times each, so there is no need
|
||
* to use a more expensive sleep method.
|
||
*/
|
||
|
||
/* Write register offset */
|
||
iowrite32be(RTC_EXICSR, iob + EXICSR);
|
||
iowrite32be(RTC_EXIDATA_W | (reg << 8), iob + EXIDATA);
|
||
iowrite32be(RTC_EXICR_W, iob + EXICR);
|
||
while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
|
||
cpu_relax();
|
||
|
||
/* Write data */
|
||
iowrite32be(RTC_EXICSR, iob + EXICSR);
|
||
iowrite32be(data, iob + EXIDATA);
|
||
iowrite32be(RTC_EXICR_W, iob + EXICR);
|
||
while (!(ioread32be(iob + EXICSR) & EXICSR_INTSET))
|
||
cpu_relax();
|
||
|
||
/* Clear channel parameters */
|
||
iowrite32be(0, iob + EXICSR);
|
||
|
||
return 0;
|
||
}
|
||
|
||
static const struct regmap_bus exi_bus = {
|
||
/* TODO: is that true? Not that it matters here, but still. */
|
||
.fast_io = true,
|
||
.reg_read = exi_read,
|
||
.reg_write = exi_write,
|
||
};
|
||
|
||
static int gamecube_rtc_read_time(struct device *dev, struct rtc_time *t)
|
||
{
|
||
struct priv *d = dev_get_drvdata(dev);
|
||
int ret;
|
||
u32 counter;
|
||
time64_t timestamp;
|
||
|
||
ret = regmap_read(d->regmap, RTC_COUNTER, &counter);
|
||
if (ret)
|
||
return ret;
|
||
|
||
/* Add the counter and the bias to obtain the timestamp */
|
||
timestamp = (time64_t)d->rtc_bias + counter;
|
||
rtc_time64_to_tm(timestamp, t);
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int gamecube_rtc_set_time(struct device *dev, struct rtc_time *t)
|
||
{
|
||
struct priv *d = dev_get_drvdata(dev);
|
||
time64_t timestamp;
|
||
|
||
/* Subtract the timestamp and the bias to obtain the counter value */
|
||
timestamp = rtc_tm_to_time64(t);
|
||
return regmap_write(d->regmap, RTC_COUNTER, timestamp - d->rtc_bias);
|
||
}
|
||
|
||
static int gamecube_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
|
||
{
|
||
struct priv *d = dev_get_drvdata(dev);
|
||
int value;
|
||
int control0;
|
||
int ret;
|
||
|
||
switch (cmd) {
|
||
case RTC_VL_READ:
|
||
ret = regmap_read(d->regmap, RTC_CONTROL0, &control0);
|
||
if (ret)
|
||
return ret;
|
||
|
||
value = 0;
|
||
if (control0 & RTC_CONTROL0_UNSTABLE_POWER)
|
||
value |= RTC_VL_DATA_INVALID;
|
||
if (control0 & RTC_CONTROL0_LOW_BATTERY)
|
||
value |= RTC_VL_BACKUP_LOW;
|
||
return put_user(value, (unsigned int __user *)arg);
|
||
|
||
default:
|
||
return -ENOIOCTLCMD;
|
||
}
|
||
}
|
||
|
||
static const struct rtc_class_ops gamecube_rtc_ops = {
|
||
.read_time = gamecube_rtc_read_time,
|
||
.set_time = gamecube_rtc_set_time,
|
||
.ioctl = gamecube_rtc_ioctl,
|
||
};
|
||
|
||
static int gamecube_rtc_read_offset_from_sram(struct priv *d)
|
||
{
|
||
struct device_node *np;
|
||
int ret;
|
||
struct resource res;
|
||
void __iomem *hw_srnprot;
|
||
u32 old;
|
||
|
||
np = of_find_compatible_node(NULL, NULL, "nintendo,latte-srnprot");
|
||
if (!np)
|
||
np = of_find_compatible_node(NULL, NULL,
|
||
"nintendo,hollywood-srnprot");
|
||
if (!np) {
|
||
pr_info("HW_SRNPROT not found, assuming a GameCube\n");
|
||
return regmap_read(d->regmap, RTC_SRAM_BIAS, &d->rtc_bias);
|
||
}
|
||
|
||
ret = of_address_to_resource(np, 0, &res);
|
||
if (ret) {
|
||
pr_err("no io memory range found\n");
|
||
return -1;
|
||
}
|
||
|
||
hw_srnprot = ioremap(res.start, resource_size(&res));
|
||
old = ioread32be(hw_srnprot);
|
||
|
||
/* TODO: figure out why we use this magic constant. I obtained it by
|
||
* reading the leftover value after boot, after IOSU already ran.
|
||
*
|
||
* On my Wii U, setting this register to 1 prevents the console from
|
||
* rebooting properly, so wiiubrew.org must be missing something.
|
||
*
|
||
* See https://wiiubrew.org/wiki/Hardware/Latte_registers
|
||
*/
|
||
if (old != 0x7bf)
|
||
iowrite32be(0x7bf, hw_srnprot);
|
||
|
||
/* Get the offset from RTC SRAM.
|
||
*
|
||
* Its default location on the GameCube and on the Wii is in the SRAM,
|
||
* while on the Wii U the bootloader needs to fill it with the contents
|
||
* of /config/rtc.xml on the SLC (the eMMC). We don’t do that from
|
||
* Linux since it requires implementing a proprietary filesystem and do
|
||
* file decryption, instead we require the bootloader to fill the same
|
||
* SRAM address as on previous consoles.
|
||
*/
|
||
ret = regmap_read(d->regmap, RTC_SRAM_BIAS, &d->rtc_bias);
|
||
if (ret) {
|
||
pr_err("failed to get the RTC bias\n");
|
||
return -1;
|
||
}
|
||
|
||
/* Reset SRAM access to how it was before, our job here is done. */
|
||
if (old != 0x7bf)
|
||
iowrite32be(old, hw_srnprot);
|
||
iounmap(hw_srnprot);
|
||
|
||
return 0;
|
||
}
|
||
|
||
static const struct regmap_range rtc_rd_ranges[] = {
|
||
regmap_reg_range(0x200000, 0x200010),
|
||
regmap_reg_range(0x204000, 0x204000),
|
||
regmap_reg_range(0x210000, 0x210001),
|
||
regmap_reg_range(0x210004, 0x210007),
|
||
regmap_reg_range(0x21000c, 0x21000d),
|
||
};
|
||
|
||
static const struct regmap_access_table rtc_rd_regs = {
|
||
.yes_ranges = rtc_rd_ranges,
|
||
.n_yes_ranges = ARRAY_SIZE(rtc_rd_ranges),
|
||
};
|
||
|
||
static const struct regmap_range rtc_wr_ranges[] = {
|
||
regmap_reg_range(0x200000, 0x200010),
|
||
regmap_reg_range(0x204000, 0x204000),
|
||
regmap_reg_range(0x210000, 0x210001),
|
||
regmap_reg_range(0x21000d, 0x21000d),
|
||
};
|
||
|
||
static const struct regmap_access_table rtc_wr_regs = {
|
||
.yes_ranges = rtc_wr_ranges,
|
||
.n_yes_ranges = ARRAY_SIZE(rtc_wr_ranges),
|
||
};
|
||
|
||
static const struct regmap_config gamecube_rtc_regmap_config = {
|
||
.reg_bits = 24,
|
||
.val_bits = 32,
|
||
.rd_table = &rtc_rd_regs,
|
||
.wr_table = &rtc_wr_regs,
|
||
.max_register = 0x21000d,
|
||
.name = "gamecube-rtc",
|
||
};
|
||
|
||
static int gamecube_rtc_probe(struct platform_device *pdev)
|
||
{
|
||
struct device *dev = &pdev->dev;
|
||
struct rtc_device *rtc;
|
||
struct priv *d;
|
||
int ret;
|
||
|
||
d = devm_kzalloc(dev, sizeof(struct priv), GFP_KERNEL);
|
||
if (!d)
|
||
return -ENOMEM;
|
||
|
||
d->iob = devm_platform_ioremap_resource(pdev, 0);
|
||
if (IS_ERR(d->iob))
|
||
return PTR_ERR(d->iob);
|
||
|
||
d->regmap = devm_regmap_init(dev, &exi_bus, d,
|
||
&gamecube_rtc_regmap_config);
|
||
if (IS_ERR(d->regmap))
|
||
return PTR_ERR(d->regmap);
|
||
|
||
ret = gamecube_rtc_read_offset_from_sram(d);
|
||
if (ret)
|
||
return ret;
|
||
dev_dbg(dev, "SRAM bias: 0x%x", d->rtc_bias);
|
||
|
||
dev_set_drvdata(dev, d);
|
||
|
||
rtc = devm_rtc_allocate_device(dev);
|
||
if (IS_ERR(rtc))
|
||
return PTR_ERR(rtc);
|
||
|
||
/* We can represent further than that, but it depends on the stored
|
||
* bias and we can’t modify it persistently on all supported consoles,
|
||
* so here we pretend to be limited to 2106.
|
||
*/
|
||
rtc->range_min = 0;
|
||
rtc->range_max = U32_MAX;
|
||
rtc->ops = &gamecube_rtc_ops;
|
||
|
||
devm_rtc_register_device(rtc);
|
||
|
||
return 0;
|
||
}
|
||
|
||
static const struct of_device_id gamecube_rtc_of_match[] = {
|
||
{.compatible = "nintendo,latte-exi" },
|
||
{.compatible = "nintendo,hollywood-exi" },
|
||
{.compatible = "nintendo,flipper-exi" },
|
||
{ }
|
||
};
|
||
MODULE_DEVICE_TABLE(of, gamecube_rtc_of_match);
|
||
|
||
static struct platform_driver gamecube_rtc_driver = {
|
||
.probe = gamecube_rtc_probe,
|
||
.driver = {
|
||
.name = "rtc-gamecube",
|
||
.of_match_table = gamecube_rtc_of_match,
|
||
},
|
||
};
|
||
module_platform_driver(gamecube_rtc_driver);
|
||
|
||
MODULE_AUTHOR("Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>");
|
||
MODULE_DESCRIPTION("Nintendo GameCube, Wii and Wii U RTC driver");
|
||
MODULE_LICENSE("GPL");
|