[linux-block.git] / drivers / mfd / atmel-flexcom.c

// 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 __maybe_unused 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");
Commit	Line	Data
caab277b	1	// SPDX-License-Identifier: GPL-2.0-only
5c41f11c CP	2	/*
	3	* Driver for Atmel Flexcom
	4	*
	5	* Copyright (C) 2015 Atmel Corporation
	6	*
	7	* Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
5c41f11c CP	8	*/
	9
	10	#include <linux/module.h>
	11	#include <linux/types.h>
	12	#include <linux/kernel.h>
	13	#include <linux/platform_device.h>
	14	#include <linux/of.h>
	15	#include <linux/of_platform.h>
	16	#include <linux/err.h>
	17	#include <linux/io.h>
	18	#include <linux/clk.h>
	19	#include <dt-bindings/mfd/atmel-flexcom.h>
	20
	21	/* I/O register offsets */
	22	#define FLEX_MR 0x0 /* Mode Register */
	23	#define FLEX_VERSION 0xfc /* Version Register */
	24
	25	/* Mode Register bit fields */
	26	#define FLEX_MR_OPMODE_OFFSET (0) /* Operating Mode */
	27	#define FLEX_MR_OPMODE_MASK (0x3 << FLEX_MR_OPMODE_OFFSET)
	28	#define FLEX_MR_OPMODE(opmode) (((opmode) << FLEX_MR_OPMODE_OFFSET) & \
	29	FLEX_MR_OPMODE_MASK)
	30
7fdec110 RI	31	struct atmel_flexcom {
	32	void __iomem *base;
	33	u32 opmode;
	34	struct clk *clk;
	35	};
5c41f11c CP	36
	37	static int atmel_flexcom_probe(struct platform_device *pdev)
	38	{
	39	struct device_node *np = pdev->dev.of_node;
5c41f11c	40	struct resource *res;
7fdec110	41	struct atmel_flexcom *ddata;
5c41f11c CP	42	int err;
5c41f11c CP	43
7fdec110 RI	44	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
	45	if (!ddata)
	46	return -ENOMEM;
	47
	48	platform_set_drvdata(pdev, ddata);
	49
	50	err = of_property_read_u32(np, "atmel,flexcom-mode", &ddata->opmode);
5c41f11c CP	51	if (err)
	52	return err;
	53
7fdec110 RI	54	if (ddata->opmode < ATMEL_FLEXCOM_MODE_USART \|\|
7fdec110 RI	55	ddata->opmode > ATMEL_FLEXCOM_MODE_TWI)
5c41f11c CP	56	return -EINVAL;
	57
	58	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
7fdec110 RI	59	ddata->base = devm_ioremap_resource(&pdev->dev, res);
	60	if (IS_ERR(ddata->base))
	61	return PTR_ERR(ddata->base);
5c41f11c	62
7fdec110 RI	63	ddata->clk = devm_clk_get(&pdev->dev, NULL);
	64	if (IS_ERR(ddata->clk))
	65	return PTR_ERR(ddata->clk);
5c41f11c	66
7fdec110	67	err = clk_prepare_enable(ddata->clk);
5c41f11c CP	68	if (err)
	69	return err;
	70
	71	/*
	72	* Set the Operating Mode in the Mode Register: only the selected device
	73	* is clocked. Hence, registers of the other serial devices remain
	74	* inaccessible and are read as zero. Also the external I/O lines of the
	75	* Flexcom are muxed to reach the selected device.
	76	*/
7fdec110	77	writel(FLEX_MR_OPMODE(ddata->opmode), ddata->base + FLEX_MR);
5c41f11c	78
7fdec110	79	clk_disable_unprepare(ddata->clk);
5c41f11c	80
ad56b2a4	81	return devm_of_platform_populate(&pdev->dev);
5c41f11c CP	82	}
	83
	84	static const struct of_device_id atmel_flexcom_of_match[] = {
	85	{ .compatible = "atmel,sama5d2-flexcom" },
	86	{ /* sentinel */ }
	87	};
	88	MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match);
	89
5d051cf9	90	static int __maybe_unused atmel_flexcom_resume_noirq(struct device *dev)
7fdec110 RI	91	{
	92	struct atmel_flexcom *ddata = dev_get_drvdata(dev);
	93	int err;
	94	u32 val;
	95
	96	err = clk_prepare_enable(ddata->clk);
	97	if (err)
	98	return err;
	99
	100	val = FLEX_MR_OPMODE(ddata->opmode),
	101	writel(val, ddata->base + FLEX_MR);
	102
	103	clk_disable_unprepare(ddata->clk);
	104
	105	return 0;
	106	}
7fdec110	107
748718bc	108	static const struct dev_pm_ops __maybe_unused atmel_flexcom_pm_ops = {
5d051cf9 CB	109	.resume_noirq = atmel_flexcom_resume_noirq,
5d051cf9 CB	110	};
7fdec110	111
5c41f11c CP	112	static struct platform_driver atmel_flexcom_driver = {
	113	.probe = atmel_flexcom_probe,
	114	.driver = {
	115	.name = "atmel_flexcom",
8c0fad75	116	.pm = pm_ptr(&atmel_flexcom_pm_ops),
5c41f11c CP	117	.of_match_table = atmel_flexcom_of_match,
	118	},
	119	};
	120
	121	module_platform_driver(atmel_flexcom_driver);
	122
	123	MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>");
	124	MODULE_DESCRIPTION("Atmel Flexcom MFD driver");
	125	MODULE_LICENSE("GPL v2");