linux/drivers/soc/amlogic/meson-canvas.c
Neil Armstrong 382f8be045 soc: amlogic: canvas: Fix meson_canvas_get when probe failed
When probe fails, a platforn_device is still associated to the node,
but dev_get_drvdata() returns NULL.

Handle this case by returning a consistent error.

Fixes: d4983983d9 ("soc: amlogic: add meson-canvas driver")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Maxime Jourdan <mjourdan@baylibre.com>
[khilman: fixed minor typo in comment ]
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
2019-02-07 16:31:30 -08:00

200 lines
4.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2018 BayLibre, SAS
* Copyright (C) 2015 Amlogic, Inc. All rights reserved.
* Copyright (C) 2014 Endless Mobile
*/
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/soc/amlogic/meson-canvas.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/io.h>
#define NUM_CANVAS 256
/* DMC Registers */
#define DMC_CAV_LUT_DATAL 0x00
#define CANVAS_WIDTH_LBIT 29
#define CANVAS_WIDTH_LWID 3
#define DMC_CAV_LUT_DATAH 0x04
#define CANVAS_WIDTH_HBIT 0
#define CANVAS_HEIGHT_BIT 9
#define CANVAS_WRAP_BIT 22
#define CANVAS_BLKMODE_BIT 24
#define CANVAS_ENDIAN_BIT 26
#define DMC_CAV_LUT_ADDR 0x08
#define CANVAS_LUT_WR_EN BIT(9)
#define CANVAS_LUT_RD_EN BIT(8)
struct meson_canvas {
struct device *dev;
void __iomem *reg_base;
spinlock_t lock; /* canvas device lock */
u8 used[NUM_CANVAS];
};
static void canvas_write(struct meson_canvas *canvas, u32 reg, u32 val)
{
writel_relaxed(val, canvas->reg_base + reg);
}
static u32 canvas_read(struct meson_canvas *canvas, u32 reg)
{
return readl_relaxed(canvas->reg_base + reg);
}
struct meson_canvas *meson_canvas_get(struct device *dev)
{
struct device_node *canvas_node;
struct platform_device *canvas_pdev;
struct meson_canvas *canvas;
canvas_node = of_parse_phandle(dev->of_node, "amlogic,canvas", 0);
if (!canvas_node)
return ERR_PTR(-ENODEV);
canvas_pdev = of_find_device_by_node(canvas_node);
if (!canvas_pdev) {
of_node_put(canvas_node);
return ERR_PTR(-EPROBE_DEFER);
}
of_node_put(canvas_node);
/*
* If priv is NULL, it's probably because the canvas hasn't
* properly initialized. Bail out with -EINVAL because, in the
* current state, this driver probe cannot return -EPROBE_DEFER
*/
canvas = dev_get_drvdata(&canvas_pdev->dev);
if (!canvas)
return ERR_PTR(-EINVAL);
return canvas;
}
EXPORT_SYMBOL_GPL(meson_canvas_get);
int meson_canvas_config(struct meson_canvas *canvas, u8 canvas_index,
u32 addr, u32 stride, u32 height,
unsigned int wrap,
unsigned int blkmode,
unsigned int endian)
{
unsigned long flags;
spin_lock_irqsave(&canvas->lock, flags);
if (!canvas->used[canvas_index]) {
dev_err(canvas->dev,
"Trying to setup non allocated canvas %u\n",
canvas_index);
spin_unlock_irqrestore(&canvas->lock, flags);
return -EINVAL;
}
canvas_write(canvas, DMC_CAV_LUT_DATAL,
((addr + 7) >> 3) |
(((stride + 7) >> 3) << CANVAS_WIDTH_LBIT));
canvas_write(canvas, DMC_CAV_LUT_DATAH,
((((stride + 7) >> 3) >> CANVAS_WIDTH_LWID) <<
CANVAS_WIDTH_HBIT) |
(height << CANVAS_HEIGHT_BIT) |
(wrap << CANVAS_WRAP_BIT) |
(blkmode << CANVAS_BLKMODE_BIT) |
(endian << CANVAS_ENDIAN_BIT));
canvas_write(canvas, DMC_CAV_LUT_ADDR,
CANVAS_LUT_WR_EN | canvas_index);
/* Force a read-back to make sure everything is flushed. */
canvas_read(canvas, DMC_CAV_LUT_DATAH);
spin_unlock_irqrestore(&canvas->lock, flags);
return 0;
}
EXPORT_SYMBOL_GPL(meson_canvas_config);
int meson_canvas_alloc(struct meson_canvas *canvas, u8 *canvas_index)
{
int i;
unsigned long flags;
spin_lock_irqsave(&canvas->lock, flags);
for (i = 0; i < NUM_CANVAS; ++i) {
if (!canvas->used[i]) {
canvas->used[i] = 1;
spin_unlock_irqrestore(&canvas->lock, flags);
*canvas_index = i;
return 0;
}
}
spin_unlock_irqrestore(&canvas->lock, flags);
dev_err(canvas->dev, "No more canvas available\n");
return -ENODEV;
}
EXPORT_SYMBOL_GPL(meson_canvas_alloc);
int meson_canvas_free(struct meson_canvas *canvas, u8 canvas_index)
{
unsigned long flags;
spin_lock_irqsave(&canvas->lock, flags);
if (!canvas->used[canvas_index]) {
dev_err(canvas->dev,
"Trying to free unused canvas %u\n", canvas_index);
spin_unlock_irqrestore(&canvas->lock, flags);
return -EINVAL;
}
canvas->used[canvas_index] = 0;
spin_unlock_irqrestore(&canvas->lock, flags);
return 0;
}
EXPORT_SYMBOL_GPL(meson_canvas_free);
static int meson_canvas_probe(struct platform_device *pdev)
{
struct resource *res;
struct meson_canvas *canvas;
struct device *dev = &pdev->dev;
canvas = devm_kzalloc(dev, sizeof(*canvas), GFP_KERNEL);
if (!canvas)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
canvas->reg_base = devm_ioremap_resource(dev, res);
if (IS_ERR(canvas->reg_base))
return PTR_ERR(canvas->reg_base);
canvas->dev = dev;
spin_lock_init(&canvas->lock);
dev_set_drvdata(dev, canvas);
return 0;
}
static const struct of_device_id canvas_dt_match[] = {
{ .compatible = "amlogic,canvas" },
{}
};
MODULE_DEVICE_TABLE(of, canvas_dt_match);
static struct platform_driver meson_canvas_driver = {
.probe = meson_canvas_probe,
.driver = {
.name = "amlogic-canvas",
.of_match_table = canvas_dt_match,
},
};
module_platform_driver(meson_canvas_driver);
MODULE_DESCRIPTION("Amlogic Canvas driver");
MODULE_AUTHOR("Maxime Jourdan <mjourdan@baylibre.com>");
MODULE_LICENSE("GPL");