307 lines
7.0 KiB
C
307 lines
7.0 KiB
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");
|