linux/drivers/nvmem/zynqmp_nvmem.c
Rajan Vaja 3d03137864 drivers: Defer probe if firmware is not ready
Driver needs ZynqMP firmware interface to call EEMI
APIs. In case firmware is not ready, dependent drivers
should wait until the firmware is ready.

Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Jolly Shah <jollys@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2019-03-18 13:45:27 +01:00

91 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 Xilinx, Inc.
*/
#include <linux/module.h>
#include <linux/nvmem-provider.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/firmware/xlnx-zynqmp.h>
#define SILICON_REVISION_MASK 0xF
struct zynqmp_nvmem_data {
struct device *dev;
struct nvmem_device *nvmem;
};
static const struct zynqmp_eemi_ops *eemi_ops;
static int zynqmp_nvmem_read(void *context, unsigned int offset,
void *val, size_t bytes)
{
int ret;
int idcode, version;
struct zynqmp_nvmem_data *priv = context;
if (!eemi_ops->get_chipid)
return -ENXIO;
ret = eemi_ops->get_chipid(&idcode, &version);
if (ret < 0)
return ret;
dev_dbg(priv->dev, "Read chipid val %x %x\n", idcode, version);
*(int *)val = version & SILICON_REVISION_MASK;
return 0;
}
static struct nvmem_config econfig = {
.name = "zynqmp-nvmem",
.owner = THIS_MODULE,
.word_size = 1,
.size = 1,
.read_only = true,
};
static const struct of_device_id zynqmp_nvmem_match[] = {
{ .compatible = "xlnx,zynqmp-nvmem-fw", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, zynqmp_nvmem_match);
static int zynqmp_nvmem_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct zynqmp_nvmem_data *priv;
priv = devm_kzalloc(dev, sizeof(struct zynqmp_nvmem_data), GFP_KERNEL);
if (!priv)
return -ENOMEM;
eemi_ops = zynqmp_pm_get_eemi_ops();
if (IS_ERR(eemi_ops))
return PTR_ERR(eemi_ops);
priv->dev = dev;
econfig.dev = dev;
econfig.reg_read = zynqmp_nvmem_read;
econfig.priv = priv;
priv->nvmem = devm_nvmem_register(dev, &econfig);
return PTR_ERR_OR_ZERO(priv->nvmem);
}
static struct platform_driver zynqmp_nvmem_driver = {
.probe = zynqmp_nvmem_probe,
.driver = {
.name = "zynqmp-nvmem",
.of_match_table = zynqmp_nvmem_match,
},
};
module_platform_driver(zynqmp_nvmem_driver);
MODULE_AUTHOR("Michal Simek <michal.simek@xilinx.com>, Nava kishore Manne <navam@xilinx.com>");
MODULE_DESCRIPTION("ZynqMP NVMEM driver");
MODULE_LICENSE("GPL");