// SPDX-License-Identifier: GPL-2.0-only
|
/*
|
* Driver for Atmel Flexcom
|
*
|
* Copyright (C) 2015 Atmel Corporation
|
*
|
* Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
|
*/
|
|
#include <linux/module.h>
|
#include <linux/types.h>
|
#include <linux/kernel.h>
|
#include <linux/platform_device.h>
|
#include <linux/of.h>
|
#include <linux/of_platform.h>
|
#include <linux/err.h>
|
#include <linux/io.h>
|
#include <linux/clk.h>
|
#include <dt-bindings/mfd/atmel-flexcom.h>
|
|
/* I/O register offsets */
|
#define FLEX_MR 0x0 /* Mode Register */
|
#define FLEX_VERSION 0xfc /* Version Register */
|
|
/* Mode Register bit fields */
|
#define FLEX_MR_OPMODE_OFFSET (0) /* Operating Mode */
|
#define FLEX_MR_OPMODE_MASK (0x3 << FLEX_MR_OPMODE_OFFSET)
|
#define FLEX_MR_OPMODE(opmode) (((opmode) << FLEX_MR_OPMODE_OFFSET) & \
|
FLEX_MR_OPMODE_MASK)
|
|
struct atmel_flexcom {
|
void __iomem *base;
|
u32 opmode;
|
struct clk *clk;
|
};
|
|
static int atmel_flexcom_probe(struct platform_device *pdev)
|
{
|
struct device_node *np = pdev->dev.of_node;
|
struct resource *res;
|
struct atmel_flexcom *ddata;
|
int err;
|
|
ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
|
if (!ddata)
|
return -ENOMEM;
|
|
platform_set_drvdata(pdev, ddata);
|
|
err = of_property_read_u32(np, "atmel,flexcom-mode", &ddata->opmode);
|
if (err)
|
return err;
|
|
if (ddata->opmode < ATMEL_FLEXCOM_MODE_USART ||
|
ddata->opmode > ATMEL_FLEXCOM_MODE_TWI)
|
return -EINVAL;
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
ddata->base = devm_ioremap_resource(&pdev->dev, res);
|
if (IS_ERR(ddata->base))
|
return PTR_ERR(ddata->base);
|
|
ddata->clk = devm_clk_get(&pdev->dev, NULL);
|
if (IS_ERR(ddata->clk))
|
return PTR_ERR(ddata->clk);
|
|
err = clk_prepare_enable(ddata->clk);
|
if (err)
|
return err;
|
|
/*
|
* Set the Operating Mode in the Mode Register: only the selected device
|
* is clocked. Hence, registers of the other serial devices remain
|
* inaccessible and are read as zero. Also the external I/O lines of the
|
* Flexcom are muxed to reach the selected device.
|
*/
|
writel(FLEX_MR_OPMODE(ddata->opmode), ddata->base + FLEX_MR);
|
|
clk_disable_unprepare(ddata->clk);
|
|
return devm_of_platform_populate(&pdev->dev);
|
}
|
|
static const struct of_device_id atmel_flexcom_of_match[] = {
|
{ .compatible = "atmel,sama5d2-flexcom" },
|
{ /* sentinel */ }
|
};
|
MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match);
|
|
static int __maybe_unused atmel_flexcom_resume_noirq(struct device *dev)
|
{
|
struct atmel_flexcom *ddata = dev_get_drvdata(dev);
|
int err;
|
u32 val;
|
|
err = clk_prepare_enable(ddata->clk);
|
if (err)
|
return err;
|
|
val = FLEX_MR_OPMODE(ddata->opmode),
|
writel(val, ddata->base + FLEX_MR);
|
|
clk_disable_unprepare(ddata->clk);
|
|
return 0;
|
}
|
|
static const struct dev_pm_ops atmel_flexcom_pm_ops = {
|
.resume_noirq = atmel_flexcom_resume_noirq,
|
};
|
|
static struct platform_driver atmel_flexcom_driver = {
|
.probe = atmel_flexcom_probe,
|
.driver = {
|
.name = "atmel_flexcom",
|
.pm = pm_ptr(&atmel_flexcom_pm_ops),
|
.of_match_table = atmel_flexcom_of_match,
|
},
|
};
|
|
module_platform_driver(atmel_flexcom_driver);
|
|
MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>");
|
MODULE_DESCRIPTION("Atmel Flexcom MFD driver");
|
MODULE_LICENSE("GPL v2");
|
