linux/drivers/mfd/altera-sysmgr.c

201 lines
5.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2018-2019, Intel Corporation.
* Copyright (C) 2012 Freescale Semiconductor, Inc.
* Copyright (C) 2012 Linaro Ltd.
*
* Based on syscon driver.
*/
#include <linux/arm-smccc.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/mfd/altera-sysmgr.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/regmap.h>
#include <linux/slab.h>
/**
* struct altr_sysmgr - Altera SOCFPGA System Manager
* @regmap: the regmap used for System Manager accesses.
*/
struct altr_sysmgr {
struct regmap *regmap;
};
static struct platform_driver altr_sysmgr_driver;
/**
* s10_protected_reg_write
* Write to a protected SMC register.
* @base: Base address of System Manager
* @reg: Address offset of register
* @val: Value to write
* Return: INTEL_SIP_SMC_STATUS_OK (0) on success
* INTEL_SIP_SMC_REG_ERROR on error
* INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
*/
static int s10_protected_reg_write(void *base,
unsigned int reg, unsigned int val)
{
struct arm_smccc_res result;
unsigned long sysmgr_base = (unsigned long)base;
arm_smccc_smc(INTEL_SIP_SMC_REG_WRITE, sysmgr_base + reg,
val, 0, 0, 0, 0, 0, &result);
return (int)result.a0;
}
/**
* s10_protected_reg_read
* Read the status of a protected SMC register
* @base: Base address of System Manager.
* @reg: Address of register
* @val: Value read.
* Return: INTEL_SIP_SMC_STATUS_OK (0) on success
* INTEL_SIP_SMC_REG_ERROR on error
* INTEL_SIP_SMC_RETURN_UNKNOWN_FUNCTION if not supported
*/
static int s10_protected_reg_read(void *base,
unsigned int reg, unsigned int *val)
{
struct arm_smccc_res result;
unsigned long sysmgr_base = (unsigned long)base;
arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sysmgr_base + reg,
0, 0, 0, 0, 0, 0, &result);
*val = (unsigned int)result.a1;
return (int)result.a0;
}
static struct regmap_config altr_sysmgr_regmap_cfg = {
.name = "altr_sysmgr",
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.fast_io = true,
.use_single_read = true,
.use_single_write = true,
};
/**
* altr_sysmgr_regmap_lookup_by_phandle
* Find the sysmgr previous configured in probe() and return regmap property.
* Return: regmap if found or error if not found.
*
* @np: Pointer to device's Device Tree node
* @property: Device Tree property name which references the sysmgr
*/
struct regmap *altr_sysmgr_regmap_lookup_by_phandle(struct device_node *np,
const char *property)
{
struct device *dev;
struct altr_sysmgr *sysmgr;
struct device_node *sysmgr_np;
if (property)
sysmgr_np = of_parse_phandle(np, property, 0);
else
sysmgr_np = np;
if (!sysmgr_np)
return ERR_PTR(-ENODEV);
dev = driver_find_device_by_of_node(&altr_sysmgr_driver.driver,
(void *)sysmgr_np);
of_node_put(sysmgr_np);
if (!dev)
return ERR_PTR(-EPROBE_DEFER);
sysmgr = dev_get_drvdata(dev);
return sysmgr->regmap;
}
EXPORT_SYMBOL_GPL(altr_sysmgr_regmap_lookup_by_phandle);
static int sysmgr_probe(struct platform_device *pdev)
{
struct altr_sysmgr *sysmgr;
struct regmap *regmap;
struct resource *res;
struct regmap_config sysmgr_config = altr_sysmgr_regmap_cfg;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
void __iomem *base;
sysmgr = devm_kzalloc(dev, sizeof(*sysmgr), GFP_KERNEL);
if (!sysmgr)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENOENT;
sysmgr_config.max_register = resource_size(res) -
sysmgr_config.reg_stride;
if (of_device_is_compatible(np, "altr,sys-mgr-s10")) {
sysmgr_config.reg_read = s10_protected_reg_read;
sysmgr_config.reg_write = s10_protected_reg_write;
/* Need physical address for SMCC call */
regmap = devm_regmap_init(dev, NULL, (void *)res->start,
&sysmgr_config);
} else {
base = devm_ioremap(dev, res->start, resource_size(res));
if (!base)
return -ENOMEM;
sysmgr_config.max_register = res->end - res->start - 3;
regmap = devm_regmap_init_mmio(dev, base, &sysmgr_config);
}
if (IS_ERR(regmap)) {
pr_err("regmap init failed\n");
return PTR_ERR(regmap);
}
sysmgr->regmap = regmap;
platform_set_drvdata(pdev, sysmgr);
return 0;
}
static const struct of_device_id altr_sysmgr_of_match[] = {
{ .compatible = "altr,sys-mgr" },
{ .compatible = "altr,sys-mgr-s10" },
{},
};
MODULE_DEVICE_TABLE(of, altr_sysmgr_of_match);
static struct platform_driver altr_sysmgr_driver = {
.probe = sysmgr_probe,
.driver = {
.name = "altr,system_manager",
.of_match_table = altr_sysmgr_of_match,
},
};
static int __init altr_sysmgr_init(void)
{
return platform_driver_register(&altr_sysmgr_driver);
}
core_initcall(altr_sysmgr_init);
static void __exit altr_sysmgr_exit(void)
{
platform_driver_unregister(&altr_sysmgr_driver);
}
module_exit(altr_sysmgr_exit);
MODULE_AUTHOR("Thor Thayer <>");
MODULE_DESCRIPTION("SOCFPGA System Manager driver");
MODULE_LICENSE("GPL v2");