// SPDX-License-Identifier: GPL-2.0+
/*
* SoC driver for Cirrus EP93xx chips.
* Copyright (C) 2022 Nikita Shubin <[email protected]>
*
* Based on a rewrite of arch/arm/mach-ep93xx/core.c
* Copyright (C) 2006 Lennert Buytenhek <[email protected]>
* Copyright (C) 2007 Herbert Valerio Riedel <[email protected]>
*
* Thanks go to Michael Burian and Ray Lehtiniemi for their key
* role in the ep93xx Linux community.
*/
#include <linux/bits.h>
#include <linux/cleanup.h>
#include <linux/init.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/sys_soc.h>
#include <linux/soc/cirrus/ep93xx.h>
#define EP93XX_SYSCON_DEVCFG 0x80
#define EP93XX_SWLOCK_MAGICK 0xaa
#define EP93XX_SYSCON_SWLOCK 0xc0
#define EP93XX_SYSCON_SYSCFG 0x9c
#define EP93XX_SYSCON_SYSCFG_REV_MASK GENMASK(31, 28)
#define EP93XX_SYSCON_SYSCFG_REV_SHIFT 28
struct ep93xx_map_info {
spinlock_t lock;
void __iomem *base;
struct regmap *map;
};
/*
* EP93xx System Controller software locked register write
*
* Logic safeguards are included to condition the control signals for
* power connection to the matrix to prevent part damage. In addition, a
* software lock register is included that must be written with 0xAA
* before each register write to change the values of the four switch
* matrix control registers.
*/
static void ep93xx_regmap_write(struct regmap *map, spinlock_t *lock,
unsigned int reg, unsigned int val)
{
guard(spinlock_irqsave)(lock);
regmap_write(map, EP93XX_SYSCON_SWLOCK, EP93XX_SWLOCK_MAGICK);
regmap_write(map, reg, val);
}
static void ep93xx_regmap_update_bits(struct regmap *map, spinlock_t *lock,
unsigned int reg, unsigned int mask,
unsigned int val)
{
guard(spinlock_irqsave)(lock);
regmap_write(map, EP93XX_SYSCON_SWLOCK, EP93XX_SWLOCK_MAGICK);
/* force write is required to clear swlock if no changes are made */
regmap_update_bits_base(map, reg, mask, val, NULL, false, true);
}
static void ep93xx_unregister_adev(void *_adev)
{
struct auxiliary_device *adev = _adev;
auxiliary_device_delete(adev);
auxiliary_device_uninit(adev);
}
static void ep93xx_adev_release(struct device *dev)
{
struct auxiliary_device *adev = to_auxiliary_dev(dev);
struct ep93xx_regmap_adev *rdev = to_ep93xx_regmap_adev(adev);
kfree(rdev);
}
static struct auxiliary_device __init *ep93xx_adev_alloc(struct device *parent,
const char *name,
struct ep93xx_map_info *info)
{
struct ep93xx_regmap_adev *rdev __free(kfree) = NULL;
struct auxiliary_device *adev;
int ret;
rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);
if (!rdev)
return ERR_PTR(-ENOMEM);
rdev->map = info->map;
rdev->base = info->base;
rdev->lock = &info->lock;
rdev->write = ep93xx_regmap_write;
rdev->update_bits = ep93xx_regmap_update_bits;
adev = &rdev->adev;
adev->name = name;
adev->dev.parent = parent;
adev->dev.release = ep93xx_adev_release;
ret = auxiliary_device_init(adev);
if (ret)
return ERR_PTR(ret);
return &no_free_ptr(rdev)->adev;
}
static int __init ep93xx_controller_register(struct device *parent, const char *name,
struct ep93xx_map_info *info)
{
struct auxiliary_device *adev;
int ret;
adev = ep93xx_adev_alloc(parent, name, info);
if (IS_ERR(adev))
return PTR_ERR(adev);
ret = auxiliary_device_add(adev);
if (ret) {
auxiliary_device_uninit(adev);
return ret;
}
return devm_add_action_or_reset(parent, ep93xx_unregister_adev, adev);
}
static unsigned int __init ep93xx_soc_revision(struct regmap *map)
{
unsigned int val;
regmap_read(map, EP93XX_SYSCON_SYSCFG, &val);
val &= EP93XX_SYSCON_SYSCFG_REV_MASK;
val >>= EP93XX_SYSCON_SYSCFG_REV_SHIFT;
return val;
}
static const char __init *ep93xx_get_soc_rev(unsigned int rev)
{
switch (rev) {
case EP93XX_CHIP_REV_D0:
return "D0";
case EP93XX_CHIP_REV_D1:
return "D1";
case EP93XX_CHIP_REV_E0:
return "E0";
case EP93XX_CHIP_REV_E1:
return "E1";
case EP93XX_CHIP_REV_E2:
return "E2";
default:
return "unknown";
}
}
static const char *pinctrl_names[] __initconst = {
"pinctrl-ep9301", /* EP93XX_9301_SOC */
"pinctrl-ep9307", /* EP93XX_9307_SOC */
"pinctrl-ep9312", /* EP93XX_9312_SOC */
};
static int __init ep93xx_syscon_probe(struct platform_device *pdev)
{
enum ep93xx_soc_model model;
struct ep93xx_map_info *map_info;
struct soc_device_attribute *attrs;
struct soc_device *soc_dev;
struct device *dev = &pdev->dev;
struct regmap *map;
void __iomem *base;
unsigned int rev;
int ret;
model = (enum ep93xx_soc_model)(uintptr_t)device_get_match_data(dev);
map = device_node_to_regmap(dev->of_node);
if (IS_ERR(map))
return PTR_ERR(map);
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
attrs = devm_kzalloc(dev, sizeof(*attrs), GFP_KERNEL);
if (!attrs)
return -ENOMEM;
rev = ep93xx_soc_revision(map);
attrs->machine = of_flat_dt_get_machine_name();
attrs->family = "Cirrus Logic EP93xx";
attrs->revision = ep93xx_get_soc_rev(rev);
soc_dev = soc_device_register(attrs);
if (IS_ERR(soc_dev))
return PTR_ERR(soc_dev);
map_info = devm_kzalloc(dev, sizeof(*map_info), GFP_KERNEL);
if (!map_info)
return -ENOMEM;
spin_lock_init(&map_info->lock);
map_info->map = map;
map_info->base = base;
ret = ep93xx_controller_register(dev, pinctrl_names[model], map_info);
if (ret)
dev_err(dev, "registering pinctrl controller failed\n");
/*
* EP93xx SSP clock rate was doubled in version E2. For more information
* see section 6 "2x SSP (Synchronous Serial Port) Clock – Revision E2 only":
* http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
*/
if (rev == EP93XX_CHIP_REV_E2)
ret = ep93xx_controller_register(dev, "clk-ep93xx.e2", map_info);
else
ret = ep93xx_controller_register(dev, "clk-ep93xx", map_info);
if (ret)
dev_err(dev, "registering clock controller failed\n");
ret = ep93xx_controller_register(dev, "reset-ep93xx", map_info);
if (ret)
dev_err(dev, "registering reset controller failed\n");
return 0;
}
static const struct of_device_id ep9301_syscon_of_device_ids[] = {
{ .compatible = "cirrus,ep9301-syscon", .data = (void *)EP93XX_9301_SOC },
{ .compatible = "cirrus,ep9302-syscon", .data = (void *)EP93XX_9301_SOC },
{ .compatible = "cirrus,ep9307-syscon", .data = (void *)EP93XX_9307_SOC },
{ .compatible = "cirrus,ep9312-syscon", .data = (void *)EP93XX_9312_SOC },
{ .compatible = "cirrus,ep9315-syscon", .data = (void *)EP93XX_9312_SOC },
{ /* sentinel */ }
};
static struct platform_driver ep9301_syscon_driver = {
.driver = {
.name = "ep9301-syscon",
.of_match_table = ep9301_syscon_of_device_ids,
},
};
builtin_platform_driver_probe(ep9301_syscon_driver, ep93xx_syscon_probe);
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