On 08/08/2018 09:45, Jerome Brunet wrote:
> On Wed, 2018-08-08 at 00:00 +0200, Maxime Jourdan wrote:
>> Amlogic SoCs have a repository of 256 canvas which they use to
>> describe pixel buffers.
>>
>> They contain metadata like width, height, block mode, endianness [..]
>>
>> Many IPs within those SoCs like vdec/vpu rely on those canvas to read/write
>> pixels.
>>
>> Signed-off-by: Maxime Jourdan <[email protected]>
>> Tested-by: Neil Armstrong <[email protected]>
> 
> Thanks for making the changes Martin, I do prefer this version. You did not 
> have
> to drop the ops, until it is really needed because of some SoC quirks, I guess
> it is simpler this way
> 
> With some answers to the nitpicks below, feel free to add :
> 
> Reviewed-by: Jerome Brunet <[email protected]>
> 
>> ---
>>  drivers/soc/amlogic/Kconfig              |   7 +
>>  drivers/soc/amlogic/Makefile             |   1 +
>>  drivers/soc/amlogic/meson-canvas.c       | 185 +++++++++++++++++++++++
>>  include/linux/soc/amlogic/meson-canvas.h |  65 ++++++++
>>  4 files changed, 258 insertions(+)
>>  create mode 100644 drivers/soc/amlogic/meson-canvas.c
>>  create mode 100644 include/linux/soc/amlogic/meson-canvas.h
>>
>> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
>> index b04f6e4aedbc..2f282b472912 100644
>> --- a/drivers/soc/amlogic/Kconfig
>> +++ b/drivers/soc/amlogic/Kconfig
>> @@ -1,5 +1,12 @@
>>  menu "Amlogic SoC drivers"
>>  
>> +config MESON_CANVAS
>> +    tristate "Amlogic Meson Canvas driver"
>> +    depends on ARCH_MESON || COMPILE_TEST
>> +    default n
>> +    help
>> +      Say yes to support the canvas IP for Amlogic SoCs.
>> +
>>  config MESON_GX_SOCINFO
>>      bool "Amlogic Meson GX SoC Information driver"
>>      depends on ARCH_MESON || COMPILE_TEST
>> diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
>> index 8fa321893928..0ab16d35ac36 100644
>> --- a/drivers/soc/amlogic/Makefile
>> +++ b/drivers/soc/amlogic/Makefile
>> @@ -1,3 +1,4 @@
>> +obj-$(CONFIG_MESON_CANVAS) += meson-canvas.o
>>  obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
>>  obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
>>  obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
>> diff --git a/drivers/soc/amlogic/meson-canvas.c 
>> b/drivers/soc/amlogic/meson-canvas.c
>> new file mode 100644
>> index 000000000000..c461334b36d4
>> --- /dev/null
>> +++ b/drivers/soc/amlogic/meson-canvas.c
>> @@ -0,0 +1,185 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Copyright (C) 2018 Maxime Jourdan <[email protected]>
>> + * Copyright (C) 2016 BayLibre, SAS
>> + * Author: Neil Armstrong <[email protected]>
>> + * 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   0x48 /* 0x12 offset in data sheet */
>> +    #define CANVAS_WIDTH_LBIT       29
>> +    #define CANVAS_WIDTH_LWID       3
>> +#define DMC_CAV_LUT_DATAH   0x4c /* 0x13 offset in data sheet */
>> +    #define CANVAS_WIDTH_HBIT       0
>> +    #define CANVAS_HEIGHT_BIT       9
>> +    #define CANVAS_BLKMODE_BIT      24
>> +#define DMC_CAV_LUT_ADDR    0x50 /* 0x14 offset in data sheet */
>> +    #define CANVAS_LUT_WR_EN        (0x2 << 8)
>> +    #define CANVAS_LUT_RD_EN        (0x1 << 8)
>> +
>> +struct meson_canvas {
>> +    struct device *dev;
>> +    struct regmap *regmap_dmc;
>> +    spinlock_t lock; /* canvas device lock */
>> +    u8 used[NUM_CANVAS];
>> +};
>> +
>> +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) {
>> +            dev_err(dev, "Unable to find canvas pdev\n");
>> +            return ERR_PTR(-ENODEV);
>> +    }

I should be -EPROBE_DEFER here since the canvas driver maybe hasn't probed yet.

>> +
>> +    canvas = dev_get_drvdata(&canvas_pdev->dev);
>> +    if (!canvas)
>> +            return ERR_PTR(-ENODEV);
> 
> You've got your device at this point, maybe EINVAL instead ?

This shouldn't fail here... I'm not sure what should be the error.

> 
>> +
>> +    return canvas;
>> +}
>> +EXPORT_SYMBOL_GPL(meson_canvas_get);
>> +
>> +int meson_canvas_setup(struct meson_canvas *canvas, u8 canvas_index,
>> +                   u32 addr, u32 stride, u32 height,
>> +                   unsigned int wrap,
>> +                   unsigned int blkmode,
>> +                   unsigned int endian)
>> +{
>> +    struct regmap *regmap = canvas->regmap_dmc;
>> +    unsigned long flags;
>> +    u32 val;
>> +
>> +    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;
>> +    }
>> +
>> +    regmap_write(regmap, DMC_CAV_LUT_DATAL,
>> +                 ((addr + 7) >> 3) |
>> +                 (((stride + 7) >> 3) << CANVAS_WIDTH_LBIT));
>> +
>> +    regmap_write(regmap, DMC_CAV_LUT_DATAH,
>> +                 ((((stride + 7) >> 3) >> CANVAS_WIDTH_LWID) <<
>> +                                            CANVAS_WIDTH_HBIT) |
>> +                 (height << CANVAS_HEIGHT_BIT) |
>> +                 (wrap << 22) |
>> +                 (blkmode << CANVAS_BLKMODE_BIT) |
>> +                 (endian << 26));
>> +
>> +    regmap_write(regmap, DMC_CAV_LUT_ADDR,
>> +                 CANVAS_LUT_WR_EN | canvas_index);
>> +
>> +    /* Force a read-back to make sure everything is flushed. */
>> +    regmap_read(regmap, DMC_CAV_LUT_DATAH, &val);
> 
> I suppose this something you got from the vendor kernel ? Out of curiosity, 
> have
> you tried w/o it ? I am wondering if this is really necessary ? 


It's explicit in the Amlogic source, you need a readback to make sure it's 
taken in account.

> 
> 
>> +    spin_unlock_irqrestore(&canvas->lock, flags);
>> +
>> +    return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(meson_canvas_setup);
>> +
>> +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 device *dev = &pdev->dev;
>> +    struct meson_canvas *canvas;
>> +
>> +    canvas = devm_kzalloc(dev, sizeof(*canvas), GFP_KERNEL);
>> +    if (!canvas)
>> +            return -ENOMEM;
>> +
>> +    canvas->regmap_dmc =
>> +            syscon_node_to_regmap(of_get_parent(dev->of_node));
>> +    if (IS_ERR(canvas->regmap_dmc)) {
>> +            dev_err(dev, "failed to get DMC regmap\n");
>> +            return PTR_ERR(canvas->regmap_dmc);
>> +    }
>> +
>> +    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 <[email protected]>");
>> +MODULE_LICENSE("GPL");
>> diff --git a/include/linux/soc/amlogic/meson-canvas.h 
>> b/include/linux/soc/amlogic/meson-canvas.h
>> new file mode 100644
>> index 000000000000..c164202d8e39
>> --- /dev/null
>> +++ b/include/linux/soc/amlogic/meson-canvas.h
>> @@ -0,0 +1,65 @@
>> +/* SPDX-License-Identifier: GPL-2.0+ */
>> +/*
>> + * Copyright (C) 2018 Maxime Jourdan <[email protected]>
>> + */
>> +#ifndef MESON_CANVAS_H
>> +#define MESON_CANVAS_H
>> +
>> +#include <linux/kernel.h>
>> +
>> +#define MESON_CANVAS_WRAP_NONE      0x00
>> +#define MESON_CANVAS_WRAP_X 0x01
>> +#define MESON_CANVAS_WRAP_Y 0x02
>> +
>> +#define MESON_CANVAS_BLKMODE_LINEAR 0x00
>> +#define MESON_CANVAS_BLKMODE_32x32  0x01
>> +#define MESON_CANVAS_BLKMODE_64x64  0x02
>> +
>> +#define MESON_CANVAS_ENDIAN_SWAP16  0x1
>> +#define MESON_CANVAS_ENDIAN_SWAP32  0x3
>> +#define MESON_CANVAS_ENDIAN_SWAP64  0x7
>> +#define MESON_CANVAS_ENDIAN_SWAP128 0xf
>> +
>> +struct meson_canvas;
>> +
>> +/**
>> + * meson_canvas_get() - get a canvas provider instance
>> + *
>> + * @dev: your device
> 
> s/your device/consumer device pointer ?
> 
>> + */
>> +struct meson_canvas *meson_canvas_get(struct device *dev);
>> +
>> +/**
>> + * meson_canvas_alloc() - take ownership of a canvas
>> + *
>> + * @canvas: canvas provider instance retrieved from meson_canvas_get()
>> + * @canvas_index: will be filled with the canvas ID
>> + */
>> +int meson_canvas_alloc(struct meson_canvas *canvas, u8 *canvas_index);
>> +
>> +/**
>> + * meson_canvas_free() - remove ownership from a canvas
>> + *
>> + * @canvas: canvas provider instance retrieved from meson_canvas_get()
>> + * @canvas_index: canvas ID that was obtained via meson_canvas_alloc()
>> + */
>> +int meson_canvas_free(struct meson_canvas *canvas, u8 canvas_index);
>> +
>> +/**
>> + * meson_canvas_setup() - configure a canvas
>> + *
>> + * @canvas: canvas provider instance retrieved from meson_canvas_get()
>> + * @canvas_index: canvas ID that was obtained via meson_canvas_alloc()
>> + * @addr: physical address to the pixel buffer
>> + * @stride: width of the buffer
>> + * @height: height of the buffer
>> + * @wrap: undocumented
>> + * @blkmode: block mode (linear, 32x32, 64x64)
>> + * @endian: byte swapping (swap16, swap32, swap64, swap128)
>> + */
>> +int meson_canvas_setup(struct meson_canvas *canvas, u8 canvas_index,
>> +                   u32 addr, u32 stride, u32 height,
>> +                   unsigned int wrap, unsigned int blkmode,
>> +                   unsigned int endian);
>> +
>> +#endif
> 
> 

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