Re: [PATCH v3 05/24] drm/sun4i: Add TCON TOP driver

Chen-Yu Tsai
2018-06-28T01:47:20Z

Hi,

So I'm late to the party, but...

On Mon, Jun 25, 2018 at 8:02 PM, Jernej Skrabec <jernej.skrabec-gGgVlfcn5nU@public.gmane.org> wrote:
> As already described in DT binding, TCON TOP is responsible for
> configuring display pipeline. In this initial driver focus is on HDMI
> pipeline, so TVE and LCD configuration is not implemented.
>
> Implemented features:
> - HDMI source selection
> - clock driver (TCON and DSI gating)
> - connecting mixers and TCONS
>
> Something similar also existed in previous SoCs, except that it was part
> of first TCON.
>
> Signed-off-by: Jernej Skrabec <jernej.skrabec-gGgVlfcn5nU@public.gmane.org>
> ---
> drivers/gpu/drm/sun4i/Makefile | 3 +-
> drivers/gpu/drm/sun4i/sun8i_tcon_top.c | 300 +++++++++++++++++++++++++
> drivers/gpu/drm/sun4i/sun8i_tcon_top.h | 40 ++++
> 3 files changed, 342 insertions(+), 1 deletion(-)
> create mode 100644 drivers/gpu/drm/sun4i/sun8i_tcon_top.c
> create mode 100644 drivers/gpu/drm/sun4i/sun8i_tcon_top.h
>
> diff --git a/drivers/gpu/drm/sun4i/Makefile b/drivers/gpu/drm/sun4i/Makefile
> index 2589f4acd5ae..09fbfd6304ba 100644
> --- a/drivers/gpu/drm/sun4i/Makefile
> +++ b/drivers/gpu/drm/sun4i/Makefile
> @@ -16,7 +16,8 @@ sun8i-drm-hdmi-y += sun8i_hdmi_phy_clk.o
>
> sun8i-mixer-y += sun8i_mixer.o sun8i_ui_layer.o \
> sun8i_vi_layer.o sun8i_ui_scaler.o \
> - sun8i_vi_scaler.o sun8i_csc.o
> + sun8i_vi_scaler.o sun8i_csc.o \
> + sun8i_tcon_top.o
>
> sun4i-tcon-y += sun4i_crtc.o
> sun4i-tcon-y += sun4i_dotclock.o
> diff --git a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c
> new file mode 100644
> index 000000000000..8da0460e0028
> --- /dev/null
> +++ b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c
> @@ -0,0 +1,300 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/* Copyright (c) 2018 Jernej Skrabec <jernej.skrabec-gGgVlfcn5nU@public.gmane.org> */
> +
> +#include <drm/drmP.h>
> +
> +#include <dt-bindings/clock/sun8i-tcon-top.h>
> +
> +#include <linux/bitfield.h>
> +#include <linux/component.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/of_graph.h>
> +#include <linux/platform_device.h>
> +
> +#include "sun8i_tcon_top.h"
> +
> +static int sun8i_tcon_top_get_connected_ep_id(struct device_node *node,
> + int port_id)
> +{
> + struct device_node *ep, *remote, *port;
> + struct of_endpoint endpoint;
> +
> + port = of_graph_get_port_by_id(node, port_id);
> + if (!port)
> + return -ENOENT;
> +
> + for_each_available_child_of_node(port, ep) {
> + remote = of_graph_get_remote_port_parent(ep);
> + if (!remote)
> + continue;
> +
> + if (of_device_is_available(remote)) {
> + of_graph_parse_endpoint(ep, &endpoint);
> +
> + of_node_put(remote);
> +
> + return endpoint.id;
> + }
> +
> + of_node_put(remote);
> + }
> +
> + return -ENOENT;
> +}
> +
> +static struct clk_hw *sun8i_tcon_top_register_gate(struct device *dev,
> + struct clk *parent,
> + void __iomem *regs,
> + spinlock_t *lock,
> + u8 bit, int name_index)
> +{
> + const char *clk_name, *parent_name;
> + int ret;
> +
> + parent_name = __clk_get_name(parent);

You can simply pass in the binding clock name, and have

index = of_property_match_string(np, "clock-names", name);
parent_name = of_clk_get_parent_name(dev->of_node, index);

> + ret = of_property_read_string_index(dev->of_node,
> + "clock-output-names", name_index,
> + &clk_name);
> + if (ret)
> + return ERR_PTR(ret);
> +
> + return clk_hw_register_gate(dev, clk_name, parent_name,
> + CLK_SET_RATE_PARENT,
> + regs + TCON_TOP_GATE_SRC_REG,
> + bit, 0, lock);
> +};
> +
> +static int sun8i_tcon_top_bind(struct device *dev, struct device *master,
> + void *data)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct clk *dsi, *tcon_tv0, *tcon_tv1, *tve0, *tve1;
> + struct clk_hw_onecell_data *clk_data;
> + struct sun8i_tcon_top *tcon_top;
> + bool mixer0_unused = false;
> + struct resource *res;
> + void __iomem *regs;
> + int ret, i, id;
> + u32 val;
> +
> + tcon_top = devm_kzalloc(dev, sizeof(*tcon_top), GFP_KERNEL);
> + if (!tcon_top)
> + return -ENOMEM;
> +
> + clk_data = devm_kzalloc(dev, sizeof(*clk_data) +
> + sizeof(*clk_data->hws) * CLK_NUM,
> + GFP_KERNEL);
> + if (!clk_data)
> + return -ENOMEM;
> + tcon_top->clk_data = clk_data;
> +
> + spin_lock_init(&tcon_top->reg_lock);
> +
> + tcon_top->rst = devm_reset_control_get(dev, NULL);
> + if (IS_ERR(tcon_top->rst)) {
> + dev_err(dev, "Couldn't get our reset line\n");
> + return PTR_ERR(tcon_top->rst);
> + }
> +
> + tcon_top->bus = devm_clk_get(dev, "bus");
> + if (IS_ERR(tcon_top->bus)) {
> + dev_err(dev, "Couldn't get the bus clock\n");
> + return PTR_ERR(tcon_top->bus);
> + }
> +
> + dsi = devm_clk_get(dev, "dsi");
> + if (IS_ERR(dsi)) {
> + dev_err(dev, "Couldn't get the dsi clock\n");
> + return PTR_ERR(dsi);
> + }
> +
> + tcon_tv0 = devm_clk_get(dev, "tcon-tv0");
> + if (IS_ERR(tcon_tv0)) {
> + dev_err(dev, "Couldn't get the tcon-tv0 clock\n");
> + return PTR_ERR(tcon_tv0);
> + }
> +
> + tcon_tv1 = devm_clk_get(dev, "tcon-tv1");
> + if (IS_ERR(tcon_tv1)) {
> + dev_err(dev, "Couldn't get the tcon-tv1 clock\n");
> + return PTR_ERR(tcon_tv1);
> + }
> +
> + tve0 = devm_clk_get(dev, "tve0");
> + if (IS_ERR(tve0)) {
> + dev_err(dev, "Couldn't get the tve0 clock\n");
> + return PTR_ERR(tve0);
> + }
> +
> + tve1 = devm_clk_get(dev, "tve1");
> + if (IS_ERR(tve1)) {
> + dev_err(dev, "Couldn't get the tve1 clock\n");
> + return PTR_ERR(tve1);
> + }

So you don't actually have to hold references to the parent clocks.

ChenYu

> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + regs = devm_ioremap_resource(dev, res);
> + if (IS_ERR(regs))
> + return PTR_ERR(regs);
> +
> + ret = reset_control_deassert(tcon_top->rst);
> + if (ret) {
> + dev_err(dev, "Could not deassert ctrl reset control\n");
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(tcon_top->bus);
> + if (ret) {
> + dev_err(dev, "Could not enable bus clock\n");
> + goto err_assert_reset;
> + }
> +
> + val = 0;
> +
> + /* check if HDMI mux output is connected */
> + if (sun8i_tcon_top_get_connected_ep_id(dev->of_node, 5) >= 0) {
> + /* find HDMI input endpoint id, if it is connected at all*/
> + id = sun8i_tcon_top_get_connected_ep_id(dev->of_node, 4);
> + if (id >= 0)
> + val = FIELD_PREP(TCON_TOP_HDMI_SRC_MSK, id + 1);
> + else
> + DRM_DEBUG_DRIVER("TCON TOP HDMI input is not connected\n");
> + } else {
> + DRM_DEBUG_DRIVER("TCON TOP HDMI output is not connected\n");
> + }
> +
> + writel(val, regs + TCON_TOP_GATE_SRC_REG);
> +
> + val = 0;
> +
> + /* process mixer0 mux output */
> + id = sun8i_tcon_top_get_connected_ep_id(dev->of_node, 1);
> + if (id >= 0) {
> + val = FIELD_PREP(TCON_TOP_PORT_DE0_MSK, id);
> + } else {
> + DRM_DEBUG_DRIVER("TCON TOP mixer0 output is not connected\n");
> + mixer0_unused = true;
> + }
> +
> + /* process mixer1 mux output */
> + id = sun8i_tcon_top_get_connected_ep_id(dev->of_node, 3);
> + if (id >= 0) {
> + val |= FIELD_PREP(TCON_TOP_PORT_DE1_MSK, id);
> +
> + /*
> + * mixer0 mux has priority over mixer1 mux. We have to
> + * make sure mixer0 doesn't overtake TCON from mixer1.
> + */
> + if (mixer0_unused && id == 0)
> + val |= FIELD_PREP(TCON_TOP_PORT_DE0_MSK, 1);
> + } else {
> + DRM_DEBUG_DRIVER("TCON TOP mixer1 output is not connected\n");
> + }
> +
> + writel(val, regs + TCON_TOP_PORT_SEL_REG);
> +
> + /*
> + * TCON TOP has two muxes, which select parent clock for each TCON TV
> + * channel clock. Parent could be either TCON TV or TVE clock. For now
> + * we leave this fixed to TCON TV, since TVE driver for R40 is not yet
> + * implemented. Once it is, graph needs to be traversed to determine
> + * if TVE is active on each TCON TV. If it is, mux should be switched
> + * to TVE clock parent.
> + */
> + clk_data->hws[CLK_TCON_TOP_TV0] =
> + sun8i_tcon_top_register_gate(dev, tcon_tv0, regs,
> + &tcon_top->reg_lock,
> + TCON_TOP_TCON_TV0_GATE, 0);
> +
> + clk_data->hws[CLK_TCON_TOP_TV1] =
> + sun8i_tcon_top_register_gate(dev, tcon_tv1, regs,
> + &tcon_top->reg_lock,
> + TCON_TOP_TCON_TV1_GATE, 1);
> +
> + clk_data->hws[CLK_TCON_TOP_DSI] =
> + sun8i_tcon_top_register_gate(dev, dsi, regs,
> + &tcon_top->reg_lock,
> + TCON_TOP_TCON_DSI_GATE, 2);
> +
> + for (i = 0; i < CLK_NUM; i++)
> + if (IS_ERR(clk_data->hws[i])) {
> + ret = PTR_ERR(clk_data->hws[i]);
> + goto err_unregister_gates;
> + }
> +
> + clk_data->num = CLK_NUM;
> +
> + ret = of_clk_add_hw_provider(dev->of_node, of_clk_hw_onecell_get,
> + clk_data);
> + if (ret)
> + goto err_unregister_gates;
> +
> + dev_set_drvdata(dev, tcon_top);
> +
> + return 0;
> +
> +err_unregister_gates:
> + for (i = 0; i < CLK_NUM; i++)
> + if (clk_data->hws[i])
> + clk_hw_unregister_gate(clk_data->hws[i]);
> + clk_disable_unprepare(tcon_top->bus);
> +err_assert_reset:
> + reset_control_assert(tcon_top->rst);
> +
> + return ret;
> +}
> +
> +static void sun8i_tcon_top_unbind(struct device *dev, struct device *master,
> + void *data)
> +{
> + struct sun8i_tcon_top *tcon_top = dev_get_drvdata(dev);
> + struct clk_hw_onecell_data *clk_data = tcon_top->clk_data;
> + int i;
> +
> + of_clk_del_provider(dev->of_node);
> + for (i = 0; i < CLK_NUM; i++)
> + clk_hw_unregister_gate(clk_data->hws[i]);
> +
> + clk_disable_unprepare(tcon_top->bus);
> + reset_control_assert(tcon_top->rst);
> +}
> +
> +static const struct component_ops sun8i_tcon_top_ops = {
> + .bind = sun8i_tcon_top_bind,
> + .unbind = sun8i_tcon_top_unbind,
> +};
> +
> +static int sun8i_tcon_top_probe(struct platform_device *pdev)
> +{
> + return component_add(&pdev->dev, &sun8i_tcon_top_ops);
> +}
> +
> +static int sun8i_tcon_top_remove(struct platform_device *pdev)
> +{
> + component_del(&pdev->dev, &sun8i_tcon_top_ops);
> +
> + return 0;
> +}
> +
> +/* sun4i_drv uses this list to check if a device node is a TCON TOP */
> +const struct of_device_id sun8i_tcon_top_of_table[] = {
> + { .compatible = "allwinner,sun8i-r40-tcon-top" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, sun8i_tcon_top_of_table);
> +EXPORT_SYMBOL(sun8i_tcon_top_of_table);
> +
> +static struct platform_driver sun8i_tcon_top_platform_driver = {
> + .probe = sun8i_tcon_top_probe,
> + .remove = sun8i_tcon_top_remove,
> + .driver = {
> + .name = "sun8i-tcon-top",
> + .of_match_table = sun8i_tcon_top_of_table,
> + },
> +};
> +module_platform_driver(sun8i_tcon_top_platform_driver);
> +
> +MODULE_AUTHOR("Jernej Skrabec <jernej.skrabec-gGgVlfcn5nU@public.gmane.org>");
> +MODULE_DESCRIPTION("Allwinner R40 TCON TOP driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/gpu/drm/sun4i/sun8i_tcon_top.h b/drivers/gpu/drm/sun4i/sun8i_tcon_top.h
> new file mode 100644
> index 000000000000..39838bbfeaee
> --- /dev/null
> +++ b/drivers/gpu/drm/sun4i/sun8i_tcon_top.h
> @@ -0,0 +1,40 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/* Copyright (c) 2018 Jernej Skrabec <jernej.skrabec-gGgVlfcn5nU@public.gmane.org> */
> +
> +#ifndef _SUN8I_TCON_TOP_H_
> +#define _SUN8I_TCON_TOP_H_
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/reset.h>
> +#include <linux/spinlock.h>
> +
> +#define TCON_TOP_TCON_TV_SETUP_REG 0x00
> +
> +#define TCON_TOP_PORT_SEL_REG 0x1C
> +#define TCON_TOP_PORT_DE0_MSK GENMASK(1, 0)
> +#define TCON_TOP_PORT_DE1_MSK GENMASK(5, 4)
> +
> +#define TCON_TOP_GATE_SRC_REG 0x20
> +#define TCON_TOP_HDMI_SRC_MSK GENMASK(29, 28)
> +#define TCON_TOP_TCON_TV1_GATE 24
> +#define TCON_TOP_TCON_TV0_GATE 20
> +#define TCON_TOP_TCON_DSI_GATE 16
> +
> +#define CLK_NUM 3
> +
> +struct sun8i_tcon_top {
> + struct clk *bus;
> + struct clk_hw_onecell_data *clk_data;
> + struct reset_control *rst;
> +
> + /*
> + * spinlock is used to synchronize access to same
> + * register where multiple clock gates can be set.
> + */
> + spinlock_t reg_lock;
> +};
> +
> +extern const struct of_device_id sun8i_tcon_top_of_table[];
> +
> +#endif /* _SUN8I_TCON_TOP_H_ */
> --
> 2.18.0
>