[linux-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_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.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
 * @update: function called to update the LCD
 */
struct img_ascii_lcd_config {
	unsigned int num_chars;
	bool external_regmap;
	void (*update)(struct linedisp *linedisp);
};

/**
 * struct img_ascii_lcd_ctx - Private data 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
 * @linedisp: line display structure
 * @curr: the string currently displayed on the LCD
 */
struct img_ascii_lcd_ctx {
	union {
		void __iomem *base;
		struct regmap *regmap;
	};
	u32 offset;
	const struct img_ascii_lcd_config *cfg;
	struct linedisp linedisp;
	char curr[] __aligned(8);
};

/*
 * 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 *)&ctx->curr[0]);
	__raw_writeq(val, ctx->base);
#elif BITS_PER_LONG == 32
	val = *((u32 *)&ctx->curr[0]);
	__raw_writel(val, ctx->base);
	val = *((u32 *)&ctx->curr[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,
	.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), ctx->curr[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,
	.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,
				   ctx->curr[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,
	.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)
{
	const struct of_device_id *match;
	const struct img_ascii_lcd_config *cfg;
	struct device *dev = &pdev->dev;
	struct img_ascii_lcd_ctx *ctx;
	int err;

	match = of_match_device(img_ascii_lcd_matches, dev);
	if (!match)
		return -ENODEV;

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