[linux-2.6-block.git] / drivers / auxdisplay / img-ascii-lcd.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2016 Imagination Technologies
 * Author: Paul Burton <paul.burton@mips.com>
 */

#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include "line-display.h"

struct img_ascii_lcd_ctx;

/**
 * struct img_ascii_lcd_config - Configuration information about an LCD model
 * @num_chars: the number of characters the LCD can display
 * @external_regmap: true if registers are in a system controller, else false
 * @ops: character line display operations
 */
struct img_ascii_lcd_config {
	unsigned int num_chars;
	bool external_regmap;
	const struct linedisp_ops ops;
};

/**
 * struct img_ascii_lcd_ctx - Private data structure
 * @linedisp: line display structure
 * @base: the base address of the LCD registers
 * @regmap: the regmap through which LCD registers are accessed
 * @offset: the offset within regmap to the start of the LCD registers
 * @cfg: pointer to the LCD model configuration
 */
struct img_ascii_lcd_ctx {
	struct linedisp linedisp;
	union {
		void __iomem *base;
		struct regmap *regmap;
	};
	u32 offset;
	const struct img_ascii_lcd_config *cfg;
};

/*
 * MIPS Boston development board
 */

static void boston_update(struct linedisp *linedisp)
{
	struct img_ascii_lcd_ctx *ctx =
		container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);
	ulong val;

#if BITS_PER_LONG == 64
	val = *((u64 *)&linedisp->buf[0]);
	__raw_writeq(val, ctx->base);
#elif BITS_PER_LONG == 32
	val = *((u32 *)&linedisp->buf[0]);
	__raw_writel(val, ctx->base);
	val = *((u32 *)&linedisp->buf[4]);
	__raw_writel(val, ctx->base + 4);
#else
# error Not 32 or 64 bit
#endif
}

static struct img_ascii_lcd_config boston_config = {
	.num_chars = 8,
	.ops = {
		.update = boston_update,
	},
};

/*
 * MIPS Malta development board
 */

static void malta_update(struct linedisp *linedisp)
{
	struct img_ascii_lcd_ctx *ctx =
		container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);
	unsigned int i;
	int err = 0;

	for (i = 0; i < linedisp->num_chars; i++) {
		err = regmap_write(ctx->regmap,
				   ctx->offset + (i * 8), linedisp->buf[i]);
		if (err)
			break;
	}

	if (unlikely(err))
		pr_err_ratelimited("Failed to update LCD display: %d\n", err);
}

static struct img_ascii_lcd_config malta_config = {
	.num_chars = 8,
	.external_regmap = true,
	.ops = {
		.update = malta_update,
	},
};

/*
 * MIPS SEAD3 development board
 */

enum {
	SEAD3_REG_LCD_CTRL		= 0x00,
#define SEAD3_REG_LCD_CTRL_SETDRAM	BIT(7)
	SEAD3_REG_LCD_DATA		= 0x08,
	SEAD3_REG_CPLD_STATUS		= 0x10,
#define SEAD3_REG_CPLD_STATUS_BUSY	BIT(0)
	SEAD3_REG_CPLD_DATA		= 0x18,
#define SEAD3_REG_CPLD_DATA_BUSY	BIT(7)
};

static int sead3_wait_sm_idle(struct img_ascii_lcd_ctx *ctx)
{
	unsigned int status;
	int err;

	do {
		err = regmap_read(ctx->regmap,
				  ctx->offset + SEAD3_REG_CPLD_STATUS,
				  &status);
		if (err)
			return err;
	} while (status & SEAD3_REG_CPLD_STATUS_BUSY);

	return 0;

}

static int sead3_wait_lcd_idle(struct img_ascii_lcd_ctx *ctx)
{
	unsigned int cpld_data;
	int err;

	err = sead3_wait_sm_idle(ctx);
	if (err)
		return err;

	do {
		err = regmap_read(ctx->regmap,
				  ctx->offset + SEAD3_REG_LCD_CTRL,
				  &cpld_data);
		if (err)
			return err;

		err = sead3_wait_sm_idle(ctx);
		if (err)
			return err;

		err = regmap_read(ctx->regmap,
				  ctx->offset + SEAD3_REG_CPLD_DATA,
				  &cpld_data);
		if (err)
			return err;
	} while (cpld_data & SEAD3_REG_CPLD_DATA_BUSY);

	return 0;
}

static void sead3_update(struct linedisp *linedisp)
{
	struct img_ascii_lcd_ctx *ctx =
		container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);
	unsigned int i;
	int err = 0;

	for (i = 0; i < linedisp->num_chars; i++) {
		err = sead3_wait_lcd_idle(ctx);
		if (err)
			break;

		err = regmap_write(ctx->regmap,
				   ctx->offset + SEAD3_REG_LCD_CTRL,
				   SEAD3_REG_LCD_CTRL_SETDRAM | i);
		if (err)
			break;

		err = sead3_wait_lcd_idle(ctx);
		if (err)
			break;

		err = regmap_write(ctx->regmap,
				   ctx->offset + SEAD3_REG_LCD_DATA,
				   linedisp->buf[i]);
		if (err)
			break;
	}

	if (unlikely(err))
		pr_err_ratelimited("Failed to update LCD display: %d\n", err);
}

static struct img_ascii_lcd_config sead3_config = {
	.num_chars = 16,
	.external_regmap = true,
	.ops = {
		.update = sead3_update,
	},
};

static const struct of_device_id img_ascii_lcd_matches[] = {
	{ .compatible = "img,boston-lcd", .data = &boston_config },
	{ .compatible = "mti,malta-lcd", .data = &malta_config },
	{ .compatible = "mti,sead3-lcd", .data = &sead3_config },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, img_ascii_lcd_matches);

/**
 * img_ascii_lcd_probe() - probe an LCD display device
 * @pdev: the LCD platform device
 *
 * Probe an LCD display device, ensuring that we have the required resources in
 * order to access the LCD & setting up private data as well as sysfs files.
 *
 * Return: 0 on success, else -ERRNO
 */
static int img_ascii_lcd_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	const struct img_ascii_lcd_config *cfg = device_get_match_data(dev);
	struct img_ascii_lcd_ctx *ctx;
	int err;

	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
	if (!ctx)
		return -ENOMEM;

	if (cfg->external_regmap) {
		ctx->regmap = syscon_node_to_regmap(dev->parent->of_node);
		if (IS_ERR(ctx->regmap))
			return PTR_ERR(ctx->regmap);

		if (of_property_read_u32(dev->of_node, "offset", &ctx->offset))
			return -EINVAL;
	} else {
		ctx->base = devm_platform_ioremap_resource(pdev, 0);
		if (IS_ERR(ctx->base))
			return PTR_ERR(ctx->base);
	}

	err = linedisp_register(&ctx->linedisp, dev, cfg->num_chars, &cfg->ops);
	if (err)
		return err;

	/* for backwards compatibility */
	err = compat_only_sysfs_link_entry_to_kobj(&dev->kobj,
						   &ctx->linedisp.dev.kobj,
						   "message", NULL);
	if (err)
		goto err_unregister;

	platform_set_drvdata(pdev, ctx);
	return 0;

err_unregister:
	linedisp_unregister(&ctx->linedisp);
	return err;
}

/**
 * img_ascii_lcd_remove() - remove an LCD display device
 * @pdev: the LCD platform device
 *
 * Remove an LCD display device, freeing private resources & ensuring that the
 * driver stops using the LCD display registers.
 *
 * Return: 0
 */
static int img_ascii_lcd_remove(struct platform_device *pdev)
{
	struct img_ascii_lcd_ctx *ctx = platform_get_drvdata(pdev);

	sysfs_remove_link(&pdev->dev.kobj, "message");
	linedisp_unregister(&ctx->linedisp);
	return 0;
}

static struct platform_driver img_ascii_lcd_driver = {
	.driver = {
		.name		= "img-ascii-lcd",
		.of_match_table	= img_ascii_lcd_matches,
	},
	.probe	= img_ascii_lcd_probe,
	.remove	= img_ascii_lcd_remove,
};
module_platform_driver(img_ascii_lcd_driver);

MODULE_DESCRIPTION("Imagination Technologies ASCII LCD Display");
MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>");
MODULE_LICENSE("GPL");
MODULE_IMPORT_NS(LINEDISP);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
0cad855f PB	2	/*
0cad855f PB	3	* Copyright (C) 2016 Imagination Technologies
fb615d61	4	* Author: Paul Burton <paul.burton@mips.com>
0cad855f PB	5	*/
0cad855f PB	6
0cad855f PB	7	#include <linux/kernel.h>
	8	#include <linux/io.h>
	9	#include <linux/mfd/syscon.h>
	10	#include <linux/module.h>
c52391fa	11	#include <linux/of.h>
0cad855f	12	#include <linux/platform_device.h>
c52391fa	13	#include <linux/property.h>
0cad855f PB	14	#include <linux/regmap.h>
0cad855f PB	15	#include <linux/slab.h>
7e76aece GU	16
7e76aece GU	17	#include "line-display.h"
0cad855f PB	18
	19	struct img_ascii_lcd_ctx;
	20
	21	/**
	22	* struct img_ascii_lcd_config - Configuration information about an LCD model
	23	* @num_chars: the number of characters the LCD can display
	24	* @external_regmap: true if registers are in a system controller, else false
70fb97c0	25	* @ops: character line display operations
0cad855f PB	26	*/
	27	struct img_ascii_lcd_config {
	28	unsigned int num_chars;
	29	bool external_regmap;
70fb97c0	30	const struct linedisp_ops ops;
0cad855f PB	31	};
	32
	33	/**
	34	* struct img_ascii_lcd_ctx - Private data structure
a8fc3d58	35	* @linedisp: line display structure
0cad855f PB	36	* @base: the base address of the LCD registers
	37	* @regmap: the regmap through which LCD registers are accessed
	38	* @offset: the offset within regmap to the start of the LCD registers
	39	* @cfg: pointer to the LCD model configuration
0cad855f PB	40	*/
0cad855f PB	41	struct img_ascii_lcd_ctx {
a8fc3d58	42	struct linedisp linedisp;
0cad855f PB	43	union {
	44	void __iomem *base;
	45	struct regmap *regmap;
	46	};
	47	u32 offset;
	48	const struct img_ascii_lcd_config *cfg;
0cad855f PB	49	};
	50
	51	/*
	52	* MIPS Boston development board
	53	*/
	54
7e76aece	55	static void boston_update(struct linedisp *linedisp)
0cad855f	56	{
7e76aece GU	57	struct img_ascii_lcd_ctx *ctx =
7e76aece GU	58	container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);
0cad855f PB	59	ulong val;
	60
	61	#if BITS_PER_LONG == 64
4ce026d5	62	val = ((u64 )&linedisp->buf[0]);
0cad855f PB	63	__raw_writeq(val, ctx->base);
0cad855f PB	64	#elif BITS_PER_LONG == 32
4ce026d5	65	val = ((u32 )&linedisp->buf[0]);
0cad855f	66	__raw_writel(val, ctx->base);
4ce026d5	67	val = ((u32 )&linedisp->buf[4]);
0cad855f PB	68	__raw_writel(val, ctx->base + 4);
	69	#else
	70	# error Not 32 or 64 bit
	71	#endif
	72	}
	73
	74	static struct img_ascii_lcd_config boston_config = {
	75	.num_chars = 8,
70fb97c0 AS	76	.ops = {
	77	.update = boston_update,
	78	},
0cad855f PB	79	};
	80
	81	/*
	82	* MIPS Malta development board
	83	*/
	84
7e76aece	85	static void malta_update(struct linedisp *linedisp)
0cad855f	86	{
7e76aece GU	87	struct img_ascii_lcd_ctx *ctx =
7e76aece GU	88	container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);
0cad855f	89	unsigned int i;
26a2c54d	90	int err = 0;
0cad855f	91
7e76aece	92	for (i = 0; i < linedisp->num_chars; i++) {
0cad855f	93	err = regmap_write(ctx->regmap,
4ce026d5	94	ctx->offset + (i * 8), linedisp->buf[i]);
0cad855f PB	95	if (err)
	96	break;
	97	}
	98
	99	if (unlikely(err))
	100	pr_err_ratelimited("Failed to update LCD display: %d\n", err);
	101	}
	102
	103	static struct img_ascii_lcd_config malta_config = {
	104	.num_chars = 8,
	105	.external_regmap = true,
70fb97c0 AS	106	.ops = {
	107	.update = malta_update,
	108	},
0cad855f PB	109	};
	110
	111	/*
	112	* MIPS SEAD3 development board
	113	*/
	114
	115	enum {
	116	SEAD3_REG_LCD_CTRL = 0x00,
	117	#define SEAD3_REG_LCD_CTRL_SETDRAM BIT(7)
	118	SEAD3_REG_LCD_DATA = 0x08,
	119	SEAD3_REG_CPLD_STATUS = 0x10,
	120	#define SEAD3_REG_CPLD_STATUS_BUSY BIT(0)
	121	SEAD3_REG_CPLD_DATA = 0x18,
	122	#define SEAD3_REG_CPLD_DATA_BUSY BIT(7)
	123	};
	124
	125	static int sead3_wait_sm_idle(struct img_ascii_lcd_ctx *ctx)
	126	{
	127	unsigned int status;
	128	int err;
	129
	130	do {
	131	err = regmap_read(ctx->regmap,
	132	ctx->offset + SEAD3_REG_CPLD_STATUS,
	133	&status);
	134	if (err)
	135	return err;
	136	} while (status & SEAD3_REG_CPLD_STATUS_BUSY);
	137
	138	return 0;
	139
	140	}
	141
	142	static int sead3_wait_lcd_idle(struct img_ascii_lcd_ctx *ctx)
	143	{
	144	unsigned int cpld_data;
	145	int err;
	146
	147	err = sead3_wait_sm_idle(ctx);
	148	if (err)
	149	return err;
	150
	151	do {
	152	err = regmap_read(ctx->regmap,
	153	ctx->offset + SEAD3_REG_LCD_CTRL,
	154	&cpld_data);
	155	if (err)
	156	return err;
	157
	158	err = sead3_wait_sm_idle(ctx);
	159	if (err)
	160	return err;
	161
	162	err = regmap_read(ctx->regmap,
	163	ctx->offset + SEAD3_REG_CPLD_DATA,
	164	&cpld_data);
	165	if (err)
	166	return err;
	167	} while (cpld_data & SEAD3_REG_CPLD_DATA_BUSY);
	168
	169	return 0;
	170	}
	171
7e76aece	172	static void sead3_update(struct linedisp *linedisp)
0cad855f	173	{
7e76aece GU	174	struct img_ascii_lcd_ctx *ctx =
7e76aece GU	175	container_of(linedisp, struct img_ascii_lcd_ctx, linedisp);
0cad855f	176	unsigned int i;
26a2c54d	177	int err = 0;
0cad855f	178
7e76aece	179	for (i = 0; i < linedisp->num_chars; i++) {
0cad855f PB	180	err = sead3_wait_lcd_idle(ctx);
	181	if (err)
	182	break;
	183
	184	err = regmap_write(ctx->regmap,
	185	ctx->offset + SEAD3_REG_LCD_CTRL,
	186	SEAD3_REG_LCD_CTRL_SETDRAM \| i);
	187	if (err)
	188	break;
	189
	190	err = sead3_wait_lcd_idle(ctx);
	191	if (err)
	192	break;
	193
	194	err = regmap_write(ctx->regmap,
	195	ctx->offset + SEAD3_REG_LCD_DATA,
4ce026d5	196	linedisp->buf[i]);
0cad855f PB	197	if (err)
	198	break;
	199	}
	200
	201	if (unlikely(err))
	202	pr_err_ratelimited("Failed to update LCD display: %d\n", err);
	203	}
	204
	205	static struct img_ascii_lcd_config sead3_config = {
	206	.num_chars = 16,
	207	.external_regmap = true,
70fb97c0 AS	208	.ops = {
	209	.update = sead3_update,
	210	},
0cad855f PB	211	};
	212
	213	static const struct of_device_id img_ascii_lcd_matches[] = {
	214	{ .compatible = "img,boston-lcd", .data = &boston_config },
	215	{ .compatible = "mti,malta-lcd", .data = &malta_config },
	216	{ .compatible = "mti,sead3-lcd", .data = &sead3_config },
abda288b	217	{ /* sentinel */ }
0cad855f	218	};
750100a4	219	MODULE_DEVICE_TABLE(of, img_ascii_lcd_matches);
0cad855f	220
0cad855f PB	221	/**
	222	* img_ascii_lcd_probe() - probe an LCD display device
	223	* @pdev: the LCD platform device
	224	*
	225	* Probe an LCD display device, ensuring that we have the required resources in
	226	* order to access the LCD & setting up private data as well as sysfs files.
	227	*
	228	* Return: 0 on success, else -ERRNO
	229	*/
	230	static int img_ascii_lcd_probe(struct platform_device *pdev)
	231	{
7b88e553	232	struct device *dev = &pdev->dev;
c52391fa	233	const struct img_ascii_lcd_config *cfg = device_get_match_data(dev);
0cad855f	234	struct img_ascii_lcd_ctx *ctx;
0cad855f PB	235	int err;
0cad855f PB	236
4ce026d5	237	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
0cad855f PB	238	if (!ctx)
	239	return -ENOMEM;
	240
	241	if (cfg->external_regmap) {
7b88e553	242	ctx->regmap = syscon_node_to_regmap(dev->parent->of_node);
0cad855f PB	243	if (IS_ERR(ctx->regmap))
	244	return PTR_ERR(ctx->regmap);
	245
7b88e553	246	if (of_property_read_u32(dev->of_node, "offset", &ctx->offset))
0cad855f PB	247	return -EINVAL;
0cad855f PB	248	} else {
e8897e4f	249	ctx->base = devm_platform_ioremap_resource(pdev, 0);
0cad855f PB	250	if (IS_ERR(ctx->base))
	251	return PTR_ERR(ctx->base);
	252	}
	253
4ce026d5	254	err = linedisp_register(&ctx->linedisp, dev, cfg->num_chars, &cfg->ops);
0cad855f	255	if (err)
7e76aece	256	return err;
0cad855f	257
7e76aece GU	258	/* for backwards compatibility */
	259	err = compat_only_sysfs_link_entry_to_kobj(&dev->kobj,
	260	&ctx->linedisp.dev.kobj,
	261	"message", NULL);
0cad855f	262	if (err)
7e76aece	263	goto err_unregister;
0cad855f	264
7e76aece	265	platform_set_drvdata(pdev, ctx);
0cad855f	266	return 0;
7e76aece GU	267
	268	err_unregister:
	269	linedisp_unregister(&ctx->linedisp);
0cad855f PB	270	return err;
	271	}
	272
	273	/**
	274	* img_ascii_lcd_remove() - remove an LCD display device
	275	* @pdev: the LCD platform device
	276	*
	277	* Remove an LCD display device, freeing private resources & ensuring that the
	278	* driver stops using the LCD display registers.
	279	*
	280	* Return: 0
	281	*/
	282	static int img_ascii_lcd_remove(struct platform_device *pdev)
	283	{
	284	struct img_ascii_lcd_ctx *ctx = platform_get_drvdata(pdev);
	285
7e76aece GU	286	sysfs_remove_link(&pdev->dev.kobj, "message");
7e76aece GU	287	linedisp_unregister(&ctx->linedisp);
0cad855f PB	288	return 0;
	289	}
	290
	291	static struct platform_driver img_ascii_lcd_driver = {
	292	.driver = {
	293	.name = "img-ascii-lcd",
	294	.of_match_table = img_ascii_lcd_matches,
	295	},
	296	.probe = img_ascii_lcd_probe,
	297	.remove = img_ascii_lcd_remove,
	298	};
	299	module_platform_driver(img_ascii_lcd_driver);
09c479f7 JC	300
	301	MODULE_DESCRIPTION("Imagination Technologies ASCII LCD Display");
	302	MODULE_AUTHOR("Paul Burton <paul.burton@mips.com>");
	303	MODULE_LICENSE("GPL");
fe5bd82f	304	MODULE_IMPORT_NS(LINEDISP);