linux/drivers/nvmem/qcom-spmi-sdam.c
Guru Das Srinagesh 8f042191d4 nvmem: qcom-spmi-sdam: Enable multiple devices
Using pdev->id as the nvmem's config ID (which, by default, is
NVMEM_DEVID_NONE) prevents multiple instances of this driver from
probing because of the following error:

  sysfs: cannot create duplicate filename '/bus/nvmem/devices/spmi_sdam'

Use NVMEM_DEVID_AUTO as the NVMEM config ID to fix the issue.

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200722100705.7772-15-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29 17:12:09 +02:00

193 lines
4.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2017, 2020 The Linux Foundation. All rights reserved.
*/
#include <linux/device.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/nvmem-provider.h>
#include <linux/regmap.h>
#define SDAM_MEM_START 0x40
#define REGISTER_MAP_ID 0x40
#define REGISTER_MAP_VERSION 0x41
#define SDAM_SIZE 0x44
#define SDAM_PBS_TRIG_SET 0xE5
#define SDAM_PBS_TRIG_CLR 0xE6
struct sdam_chip {
struct platform_device *pdev;
struct regmap *regmap;
struct nvmem_config sdam_config;
unsigned int base;
unsigned int size;
};
/* read only register offsets */
static const u8 sdam_ro_map[] = {
REGISTER_MAP_ID,
REGISTER_MAP_VERSION,
SDAM_SIZE
};
static bool sdam_is_valid(struct sdam_chip *sdam, unsigned int offset,
size_t len)
{
unsigned int sdam_mem_end = SDAM_MEM_START + sdam->size - 1;
if (!len)
return false;
if (offset >= SDAM_MEM_START && offset <= sdam_mem_end
&& (offset + len - 1) <= sdam_mem_end)
return true;
else if ((offset == SDAM_PBS_TRIG_SET || offset == SDAM_PBS_TRIG_CLR)
&& (len == 1))
return true;
return false;
}
static bool sdam_is_ro(unsigned int offset, size_t len)
{
int i;
for (i = 0; i < ARRAY_SIZE(sdam_ro_map); i++)
if (offset <= sdam_ro_map[i] && (offset + len) > sdam_ro_map[i])
return true;
return false;
}
static int sdam_read(void *priv, unsigned int offset, void *val,
size_t bytes)
{
struct sdam_chip *sdam = priv;
struct device *dev = &sdam->pdev->dev;
int rc;
if (!sdam_is_valid(sdam, offset, bytes)) {
dev_err(dev, "Invalid SDAM offset %#x len=%zd\n",
offset, bytes);
return -EINVAL;
}
rc = regmap_bulk_read(sdam->regmap, sdam->base + offset, val, bytes);
if (rc < 0)
dev_err(dev, "Failed to read SDAM offset %#x len=%zd, rc=%d\n",
offset, bytes, rc);
return rc;
}
static int sdam_write(void *priv, unsigned int offset, void *val,
size_t bytes)
{
struct sdam_chip *sdam = priv;
struct device *dev = &sdam->pdev->dev;
int rc;
if (!sdam_is_valid(sdam, offset, bytes)) {
dev_err(dev, "Invalid SDAM offset %#x len=%zd\n",
offset, bytes);
return -EINVAL;
}
if (sdam_is_ro(offset, bytes)) {
dev_err(dev, "Invalid write offset %#x len=%zd\n",
offset, bytes);
return -EINVAL;
}
rc = regmap_bulk_write(sdam->regmap, sdam->base + offset, val, bytes);
if (rc < 0)
dev_err(dev, "Failed to write SDAM offset %#x len=%zd, rc=%d\n",
offset, bytes, rc);
return rc;
}
static int sdam_probe(struct platform_device *pdev)
{
struct sdam_chip *sdam;
struct nvmem_device *nvmem;
unsigned int val;
int rc;
sdam = devm_kzalloc(&pdev->dev, sizeof(*sdam), GFP_KERNEL);
if (!sdam)
return -ENOMEM;
sdam->regmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!sdam->regmap) {
dev_err(&pdev->dev, "Failed to get regmap handle\n");
return -ENXIO;
}
rc = of_property_read_u32(pdev->dev.of_node, "reg", &sdam->base);
if (rc < 0) {
dev_err(&pdev->dev, "Failed to get SDAM base, rc=%d\n", rc);
return -EINVAL;
}
rc = regmap_read(sdam->regmap, sdam->base + SDAM_SIZE, &val);
if (rc < 0) {
dev_err(&pdev->dev, "Failed to read SDAM_SIZE rc=%d\n", rc);
return -EINVAL;
}
sdam->size = val * 32;
sdam->sdam_config.dev = &pdev->dev;
sdam->sdam_config.name = "spmi_sdam";
sdam->sdam_config.id = NVMEM_DEVID_AUTO;
sdam->sdam_config.owner = THIS_MODULE,
sdam->sdam_config.stride = 1;
sdam->sdam_config.word_size = 1;
sdam->sdam_config.reg_read = sdam_read;
sdam->sdam_config.reg_write = sdam_write;
sdam->sdam_config.priv = sdam;
nvmem = devm_nvmem_register(&pdev->dev, &sdam->sdam_config);
if (IS_ERR(nvmem)) {
dev_err(&pdev->dev,
"Failed to register SDAM nvmem device rc=%ld\n",
PTR_ERR(nvmem));
return -ENXIO;
}
dev_dbg(&pdev->dev,
"SDAM base=%#x size=%u registered successfully\n",
sdam->base, sdam->size);
return 0;
}
static const struct of_device_id sdam_match_table[] = {
{ .compatible = "qcom,spmi-sdam" },
{},
};
static struct platform_driver sdam_driver = {
.driver = {
.name = "qcom,spmi-sdam",
.of_match_table = sdam_match_table,
},
.probe = sdam_probe,
};
static int __init sdam_init(void)
{
return platform_driver_register(&sdam_driver);
}
subsys_initcall(sdam_init);
static void __exit sdam_exit(void)
{
return platform_driver_unregister(&sdam_driver);
}
module_exit(sdam_exit);
MODULE_DESCRIPTION("QCOM SPMI SDAM driver");
MODULE_LICENSE("GPL v2");