hi Philipp:
On 2023/12/4 21:30, Philipp Zabel wrote:
> Hi Keith,
>
> On Mo, 2023-12-04 at 20:33 +0800, Keith Zhao wrote:
>> Implement drm device registration interface
>>
>> Signed-off-by: Keith Zhao <keith.z...@starfivetech.com>
>> ---
> [...]
>> diff --git a/drivers/gpu/drm/verisilicon/Kconfig
>> b/drivers/gpu/drm/verisilicon/Kconfig
>> new file mode 100644
>> index 000000000000..e10fa97635aa
>> --- /dev/null
>> +++ b/drivers/gpu/drm/verisilicon/Kconfig
>> @@ -0,0 +1,13 @@
>> +# SPDX-License-Identifier: GPL-2.0
>> +config DRM_VERISILICON
>> + tristate "DRM Support for VeriSilicon"
>> + depends on DRM
>> + select DRM_KMS_HELPER
>> + select DRM_GEM_DMA_HELPER
>> + select CMA
>> + select DMA_CMA
>> + help
>> + Choose this option if you have a VeriSilicon soc chipset.
>
> This seems a bit generic. Doesn't the VeriSilicon display controller IP
> used on JH7110 have a product name?
yes , there is a product name "dc8200", I will match it.
>
> [...]
>> diff --git a/drivers/gpu/drm/verisilicon/vs_drv.c
>> b/drivers/gpu/drm/verisilicon/vs_drv.c
>> new file mode 100644
>> index 000000000000..4fb1f29ef84b
>> --- /dev/null
>> +++ b/drivers/gpu/drm/verisilicon/vs_drv.c
>> @@ -0,0 +1,316 @@
>> +// SPDX-License-Identifier: GPL-2.0
> [...]
>> +static void vs_drm_device_release_clocks(void *res)
>> +{
>> + struct vs_drm_device *priv = res;
>> + unsigned int i;
>> +
>> + reset_control_bulk_assert(priv->nrsts, priv->rst_vout);
>> +
>> + for (i = 0; i < priv->clk_count; ++i) {
>> + if (priv->clks[i]) {
>> + clk_disable_unprepare(priv->clks[i]);
>> + clk_put(priv->clks[i]);
>> + }
>> + }
>
> Why not use the bulk API for clk as well?
ok , will do it next version
>
> [...]
>> +static int vs_drm_device_init_clocks(struct vs_drm_device *priv)
>> +{
>> + struct drm_device *dev = &priv->base;
>> + struct platform_device *pdev = to_platform_device(dev->dev);
>> + struct device_node *of_node = pdev->dev.of_node;
>> + struct clk *clock;
>> + unsigned int i;
>> + int ret;
>> +
>> + if (dev_get_platdata(&pdev->dev) || !of_node)
>> + return 0;
>> +
>> + priv->nrsts = ARRAY_SIZE(priv->rst_vout);
>> + for (int i = 0; i < priv->nrsts; ++i)
>> + priv->rst_vout[i].id = vout_resets[i];
>> + ret = devm_reset_control_bulk_get_shared(dev->dev, priv->nrsts,
>> + priv->rst_vout);
>
> I would request resets and clocks in _probe().
>
> If component_bind_all() returns -EPROBE_DEFER because of a still
> missing DSI panel backlight or similar, this doesn't have to be done
> multiple times.
I got what you mean. component_bind_all should be done multiple times
to prevent the dsi panel driver from lagging load.
in my drm subsystem , there are 2 pipeline
+------------------------------+
| |
| |
+----+ | +-------------------+ | +-------+ +------+ +------+
| +----->+ dc controller 0 +--->----->+HDMICtl| ->+ PHY +-->+PANEL0+
|AXI | | +-------------------+ | +-------+ +------+ +------+
| | | |
| | | |
| | | |
| | | |
|APB | | +-------------------+ +---------+ +------+ +-------+
| +----->+ dc controller 1 +--->---->+ dsiTx +--->+DPHY +->+ PANEL1+
| | | +-------------------+ +---------+ +------+ +-------+
+----+ | |
+------------------------------+
component_bind_all will bind the hdmi encoder and dsi encoder .
binding the hdmi encoder will always return ok .
binging the dsi encoder has a question :
I used the panel-raspberrypi-touchscreen.c as panel driver ,
this driver is a i2c device and it use a i2c command to read reg ID
if read success , it will do drm_panel_add.
if I disconnect the panel ,it will not do drm_panel_add.
dsiTx will fail to find panel , The consequence is that the inputbridge cannot
be created ,
also outputbridge cannot be created.
for encoder bind , it will fail to find the input bridge of dsi.
Under this premise, although returning -EPROBE_DEFER allows bind to be executed
multiple times,
the final result is that the entire bind fails.
returning -EPROBE_DEFER can solve panel driver from lagging load ,
but for no panel case , it will destory all pipeline (include hdmi and dsi).
I did two things:
late_initcall_sync(vs_drm_init); to make sure the panel drive has been probed;
dsi encoder bind always return ok to make sure hdmi pipeline ok at lease.
component_bind_all do once .
>
>> + if (ret) {
>> + drm_err(dev, "Failed to get reset controls\n");
>> + return ret;
>> + }
>> +
>> + priv->clk_count = of_clk_get_parent_count(of_node);
>> + if (!priv->clk_count)
>> + return 0;
>> +
>> + priv->clks = drmm_kzalloc(dev, priv->clk_count * sizeof(priv->clks[0]),
>> + GFP_KERNEL);
>> + if (!priv->clks)
>> + return -ENOMEM;
>> +
>> + for (i = 0; i < priv->clk_count; ++i) {
>> + clock = of_clk_get(of_node, i);
>> + if (IS_ERR(clock)) {
>> + ret = PTR_ERR(clock);
>> + if (ret == -EPROBE_DEFER)
>> + goto err;
>> + drm_err(dev, "clock %u not found: %d\n", i, ret);
>> + continue;
>> + }
>> + ret = clk_prepare_enable(clock);
>> + if (ret) {
>> + drm_err(dev, "failed to enable clock %u: %d\n",
>> + i, ret);
>> + clk_put(clock);
>> + continue;
>> + }
>> + priv->clks[i] = clock;
>> + }
>> +
>> + ret = reset_control_bulk_deassert(priv->nrsts, priv->rst_vout);
>> + if (ret)
>> + return ret;
>
> This should goto err, otherwise clocks are left enabled.
>
>> +
>> + return devm_add_action_or_reset(&pdev->dev,
>> + vs_drm_device_release_clocks,
>> + priv);
>> +
>> +err:
>> + while (i) {
>> + --i;
>> + if (priv->clks[i]) {
>> + clk_disable_unprepare(priv->clks[i]);
>> + clk_put(priv->clks[i]);
>> + }
>> + }
>> + return ret;
>> +}
>> +
>> +static int vs_drm_bind(struct device *dev)
>> +{
>> + struct platform_device *pdev = to_platform_device(dev);
>> + struct vs_drm_device *priv;
>> + int ret;
>> + struct drm_device *drm_dev;
>> +
>> + /* Remove existing drivers that may own the framebuffer memory. */
>> + ret = drm_aperture_remove_framebuffers(&vs_drm_driver);
>> + if (ret)
>> + return ret;
>> +
>> + priv = devm_drm_dev_alloc(dev, &vs_drm_driver, struct vs_drm_device,
>> base);
>> + if (IS_ERR(priv))
>> + return PTR_ERR(priv);
>> +
>> + priv->pitch_alignment = 64;
>
> Why is this a variable instead of a constant?
the dc controllers of VeriSilicon have different series, like dc8200 , dc9200...
Their pitch values may vary from series to series, like 64 , 128
>
>> + ret = dma_set_coherent_mask(priv->base.dev, DMA_BIT_MASK(40));
>> + if (ret)
>> + return ret;
>> +
>> + drm_dev = &priv->base;
>> + platform_set_drvdata(pdev, drm_dev);
>> +
>> + ret = vs_drm_device_init_clocks(priv);
>> + if (ret)
>> + return ret;
>> +
>> + vs_mode_config_init(drm_dev);
>> +
>> + /* Now try and bind all our sub-components */
>> + ret = component_bind_all(dev, drm_dev);
>> + if (ret)
>> + return ret;
>> +
>> + ret = drm_vblank_init(drm_dev, drm_dev->mode_config.num_crtc);
>> + if (ret)
>> + return ret;
>
> Missing component_unbind_all(), see below.
>
>> +
>> + drm_mode_config_reset(drm_dev);
>> +
>> + drm_kms_helper_poll_init(drm_dev);
>> +
>> + ret = drm_dev_register(drm_dev, 0);
>> + if (ret)
>> + return ret;
>
> Missing drm_kms_helper_poll_fini(), see below.
>
>> +
>> + drm_fbdev_generic_setup(drm_dev, 32);
>> +
>> + return 0;
>
> Here I'd expect an error path calling drm_kms_helper_poll_fini() and
> component_unbind_all() as appropriate.
>
ok
>
> regards
> Philipp
