To support multiple display pipelines, we need to keep track of the multiple display backends and TCONs registered with the driver.

Switch to lists to track registered components. Components are only appended to their respective lists if the bind process was successful. The TCON bind function now defers if a backend was not registered.

Signed-off-by: Chen-Yu Tsai wens@csie.org --- drivers/gpu/drm/sun4i/sun4i_backend.c | 6 +++++- drivers/gpu/drm/sun4i/sun4i_backend.h | 4 ++++ drivers/gpu/drm/sun4i/sun4i_drv.c | 2 ++ drivers/gpu/drm/sun4i/sun4i_drv.h | 4 +++- drivers/gpu/drm/sun4i/sun4i_tcon.c | 14 ++++++++++++-- drivers/gpu/drm/sun4i/sun4i_tcon.h | 4 ++++ 6 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c index d660741ba475..95a77c6a9161 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.c +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c @@ -19,6 +19,7 @@ #include <drm/drm_plane_helper.h>

#include <linux/component.h> +#include <linux/list.h> #include <linux/reset.h>

#include "sun4i_backend.h" @@ -310,7 +311,6 @@ static int sun4i_backend_bind(struct device *dev, struct device *master, if (!backend) return -ENOMEM; dev_set_drvdata(dev, backend); - drv->backend = backend;

res = platform_get_resource(pdev, IORESOURCE_MEM, 0); regs = devm_ioremap_resource(dev, res); @@ -369,6 +369,8 @@ static int sun4i_backend_bind(struct device *dev, struct device *master, } }

+ list_add_tail(&backend->list, &drv->backend_list); + /* Reset the registers */ for (i = 0x800; i < 0x1000; i += 4) regmap_write(backend->regs, i, 0); @@ -400,6 +402,8 @@ static void sun4i_backend_unbind(struct device *dev, struct device *master, { struct sun4i_backend *backend = dev_get_drvdata(dev);

+ list_del(&backend->list); + if (of_device_is_compatible(dev->of_node, "allwinner,sun8i-a33-display-backend")) sun4i_backend_free_sat(dev); diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.h b/drivers/gpu/drm/sun4i/sun4i_backend.h index 83e63cc702b4..9c8287309c65 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.h +++ b/drivers/gpu/drm/sun4i/sun4i_backend.h @@ -14,6 +14,7 @@ #define _SUN4I_BACKEND_H_

#include <linux/clk.h> +#include <linux/list.h> #include <linux/regmap.h> #include <linux/reset.h>

@@ -149,6 +150,9 @@ struct sun4i_backend {

struct clk *sat_clk; struct reset_control *sat_reset; + + /* Backend list management */ + struct list_head list; };

void sun4i_backend_apply_color_correction(struct sun4i_backend *backend); diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.c b/drivers/gpu/drm/sun4i/sun4i_drv.c index 767bbadcc85d..89c51fd6e9af 100644 --- a/drivers/gpu/drm/sun4i/sun4i_drv.c +++ b/drivers/gpu/drm/sun4i/sun4i_drv.c @@ -101,6 +101,8 @@ static int sun4i_drv_bind(struct device *dev) goto free_drm; } drm->dev_private = drv; + INIT_LIST_HEAD(&drv->backend_list); + INIT_LIST_HEAD(&drv->tcon_list);

ret = of_reserved_mem_device_init(dev); if (ret && ret != -ENODEV) { diff --git a/drivers/gpu/drm/sun4i/sun4i_drv.h b/drivers/gpu/drm/sun4i/sun4i_drv.h index 5df50126ff52..835bdb5cc0c2 100644 --- a/drivers/gpu/drm/sun4i/sun4i_drv.h +++ b/drivers/gpu/drm/sun4i/sun4i_drv.h @@ -14,10 +14,12 @@ #define _SUN4I_DRV_H_

#include <linux/clk.h> +#include <linux/list.h> #include <linux/regmap.h>

struct sun4i_drv { - struct sun4i_backend *backend; + struct list_head backend_list; + struct list_head tcon_list; struct sun4i_tcon *tcon;

struct drm_fbdev_cma *fbdev; diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index 3ced0b1cef6e..52f37ef9a050 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -26,6 +26,7 @@ #include <linux/regmap.h> #include <linux/reset.h>

+#include "sun4i_backend.h" #include "sun4i_crtc.h" #include "sun4i_dotclock.h" #include "sun4i_drv.h" @@ -476,14 +477,18 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master, { struct drm_device *drm = data; struct sun4i_drv *drv = drm->dev_private; + struct sun4i_backend *backend; struct sun4i_tcon *tcon; int ret;

+ /* Wait for a backend to be registered */ + if (list_empty(&drv->backend_list)) + return -EPROBE_DEFER; + tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL); if (!tcon) return -ENOMEM; dev_set_drvdata(dev, tcon); - drv->tcon = tcon; tcon->drm = drm; tcon->dev = dev; tcon->quirks = of_device_get_match_data(dev); @@ -528,7 +533,9 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master, goto err_free_dotclock; }

- tcon->crtc = sun4i_crtc_init(drm, drv->backend, tcon); + backend = list_first_entry(&drv->backend_list, + struct sun4i_backend, list); + tcon->crtc = sun4i_crtc_init(drm, backend, tcon); if (IS_ERR(tcon->crtc)) { dev_err(dev, "Couldn't create our CRTC\n"); ret = PTR_ERR(tcon->crtc); @@ -539,6 +546,8 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master, if (ret < 0) goto err_free_clocks;

+ list_add_tail(&tcon->list, &drv->tcon_list); + return 0;

err_free_dotclock: @@ -555,6 +564,7 @@ static void sun4i_tcon_unbind(struct device *dev, struct device *master, { struct sun4i_tcon *tcon = dev_get_drvdata(dev);

+ list_del(&tcon->list); sun4i_dclk_free(tcon); sun4i_tcon_free_clocks(tcon); } diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h index f636343a935d..1bda4d183eec 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.h +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h @@ -17,6 +17,7 @@ #include <drm/drm_crtc.h>

#include <linux/kernel.h> +#include <linux/list.h> #include <linux/reset.h>

#define SUN4I_TCON_GCTL_REG 0x0 @@ -172,6 +173,9 @@ struct sun4i_tcon {

/* Associated crtc */ struct sun4i_crtc *crtc; + + /* TCON list management */ + struct list_head list; };

struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node);

Some Allwinner SoCs have 2 display pipelines, as in 2 of each components, including the frontend, backend, TCON, and any other extras.

As the backend and TCON are always paired together and form the CRTC, we need to know which backend or TCON we are currently probing, so we can pair them when initializing the CRTC.

This patch figures out the backend's ID from the device tree and stores it in the backend's data structure. It does this by looking at the "reg" property of any remote endpoints connected to the backend's input port.

Signed-off-by: Chen-Yu Tsai wens@csie.org --- drivers/gpu/drm/sun4i/sun4i_backend.c | 44 +++++++++++++++++++++++++++++++++++ drivers/gpu/drm/sun4i/sun4i_backend.h | 2 ++ 2 files changed, 46 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c index e17e20036aa3..0b4222312e49 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.c +++ b/drivers/gpu/drm/sun4i/sun4i_backend.c @@ -20,6 +20,7 @@

#include <linux/component.h> #include <linux/list.h> +#include <linux/of_graph.h> #include <linux/reset.h>

#include "sun4i_backend.h" @@ -289,6 +290,45 @@ static int sun4i_backend_free_sat(struct device *dev) { return 0; }

+/* + * The display backend can take video output from the display frontend, or + * the display enhancement unit on the A80, as input for one it its layers. + * This relationship within the display pipeline is encoded in the device + * tree with of_graph, and we use it here to figure out which backend, if + * there are 2 or more, we are currently probing. The number would be in + * the "reg" property of the upstream output port endpoint. + */ +static int sun4i_backend_of_get_id(struct device_node *node) +{ + struct device_node *port, *ep; + int ret = -EINVAL; + + /* input is port 0 */ + port = of_graph_get_port_by_id(node, 0); + if (!port) + return -EINVAL; + + /* try finding an upstream endpoint */ + for_each_available_child_of_node(port, ep) { + struct device_node *remote; + u32 reg; + + remote = of_parse_phandle(ep, "remote-endpoint", 0); + if (!remote) + continue; + + ret = of_property_read_u32(remote, "reg", &reg); + if (ret) + continue; + + ret = reg; + } + + of_node_put(port); + + return ret; +} + static struct regmap_config sun4i_backend_regmap_config = { .reg_bits = 32, .val_bits = 32, @@ -312,6 +352,10 @@ static int sun4i_backend_bind(struct device *dev, struct device *master, return -ENOMEM; dev_set_drvdata(dev, backend);

+ backend->id = sun4i_backend_of_get_id(dev->of_node); + if (backend->id < 0) + return backend->id; + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); regs = devm_ioremap_resource(dev, res); if (IS_ERR(regs)) diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.h b/drivers/gpu/drm/sun4i/sun4i_backend.h index 9c8287309c65..45b7fc110590 100644 --- a/drivers/gpu/drm/sun4i/sun4i_backend.h +++ b/drivers/gpu/drm/sun4i/sun4i_backend.h @@ -151,6 +151,8 @@ struct sun4i_backend { struct clk *sat_clk; struct reset_control *sat_reset;

+ int id; + /* Backend list management */ struct list_head list; };

With Allwinner's Display Engine 1.0, each TCON's input is tied to a specific display backend, and the 2 comprise what is known as a crtc in DRM KMS land: The layer, framebuffer, and compositing functions are provided by the backend, while the TCON provides the display timing signals and vblank interrupts. This 1 to 1 relationship is represented in the device tree. On some systems there is an intermediate DRC component.

Pointers to both matching components must be provided when initializing the crtc. As the backend is always registered before the associated tcon, we can recursively search upwards through the of_graph to find the matching backend.

Signed-off-by: Chen-Yu Tsai wens@csie.org --- drivers/gpu/drm/sun4i/sun4i_tcon.c | 55 +++++++++++++++++++++++++++++++++++--- 1 file changed, 51 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index 52f37ef9a050..4409e7b6c74d 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -472,6 +472,53 @@ struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node) return of_drm_find_bridge(remote) ?: ERR_PTR(-EPROBE_DEFER); }

+/* + * On SoCs with the old display pipeline design (Display Engine 1.0), + * the TCON is always tied to just one backend. Hence we can traverse + * the of_graph upwards to find the backend our tcon is connected to, + * and take its ID as our own. + * + * We can either identify backends from their compatible strings, which + * means maintaining a large list of them. Or, since the backend is + * registered and binded before the TCON, we can just go through the + * list of registered backends and compare the device node. + */ +static struct sun4i_backend *sun4i_tcon_find_backend(struct sun4i_drv *drv, + struct device_node *node) +{ + struct device_node *port, *ep, *remote; + struct sun4i_backend *backend; + + port = of_graph_get_port_by_id(node, 0); + if (!port) + return ERR_PTR(-EINVAL); + + for_each_available_child_of_node(port, ep) { + remote = of_graph_get_remote_port_parent(ep); + if (!remote) + continue; + + /* does this node match any registered backends? */ + list_for_each_entry(backend, &drv->backend_list, list) { + if (remote == backend->node) { + of_node_put(remote); + of_node_put(port); + return backend; + } + } + + /* keep looking through upstream ports */ + backend = sun4i_tcon_find_backend(drv, remote); + if (!IS_ERR(backend)) { + of_node_put(remote); + of_node_put(port); + return backend; + } + } + + return ERR_PTR(-EINVAL); +} + static int sun4i_tcon_bind(struct device *dev, struct device *master, void *data) { @@ -481,9 +528,11 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master, struct sun4i_tcon *tcon; int ret;

- /* Wait for a backend to be registered */ - if (list_empty(&drv->backend_list)) + backend = sun4i_tcon_find_backend(drv, dev->of_node); + if (IS_ERR(backend)) { + dev_err(dev, "Couldn't find matching backend\n"); return -EPROBE_DEFER; + }

tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL); if (!tcon) @@ -533,8 +582,6 @@ static int sun4i_tcon_bind(struct device *dev, struct device *master, goto err_free_dotclock; }

- backend = list_first_entry(&drv->backend_list, - struct sun4i_backend, list); tcon->crtc = sun4i_crtc_init(drm, backend, tcon); if (IS_ERR(tcon->crtc)) { dev_err(dev, "Couldn't create our CRTC\n");

The Allwinner A31/A31s SoCs have 2 display pipelines, as in 2 display frontends, backends, and tcons each. The relationship between the backends and tcons are 1:1, but the frontends can feed either backend.

Add device nodes and of graph nodes describing this relationship.

Signed-off-by: Chen-Yu Tsai wens@csie.org --- arch/arm/boot/dts/sun6i-a31.dtsi | 168 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 167 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sun6i-a31.dtsi b/arch/arm/boot/dts/sun6i-a31.dtsi index 9c999d3788f6..dfcf64515d7f 100644 --- a/arch/arm/boot/dts/sun6i-a31.dtsi +++ b/arch/arm/boot/dts/sun6i-a31.dtsi @@ -232,7 +232,7 @@

de: display-engine { compatible = "allwinner,sun6i-a31-display-engine"; - allwinner,pipelines = <&fe0>; + allwinner,pipelines = <&fe0>, <&fe1>; status = "disabled"; };

@@ -289,6 +289,43 @@ }; };

+ tcon1: lcd-controller@01c0d000 { + compatible = "allwinner,sun6i-a31-tcon"; + reg = <0x01c0d000 0x1000>; + interrupts = <GIC_SPI 87 IRQ_TYPE_LEVEL_HIGH>; + resets = <&ccu RST_AHB1_LCD1>; + reset-names = "lcd"; + clocks = <&ccu CLK_AHB1_LCD1>, + <&ccu CLK_LCD1_CH0>, + <&ccu CLK_LCD1_CH1>; + clock-names = "ahb", + "tcon-ch0", + "tcon-ch1"; + clock-output-names = "tcon1-pixel-clock"; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + tcon1_in: port@0 { + #address-cells = <1>; + #size-cells = <0>; + reg = <0>; + + tcon1_in_drc1: endpoint@0 { + reg = <0>; + remote-endpoint = <&drc1_out_tcon1>; + }; + }; + + tcon1_out: port@1 { + #address-cells = <1>; + #size-cells = <0>; + reg = <1>; + }; + }; + }; + mmc0: mmc@01c0f000 { compatible = "allwinner,sun7i-a20-mmc"; reg = <0x01c0f000 0x1000>; @@ -896,6 +933,130 @@ reg = <0>; remote-endpoint = <&be0_in_fe0>; }; + + fe0_out_be1: endpoint@1 { + reg = <1>; + remote-endpoint = <&be1_in_fe0>; + }; + }; + }; + }; + + fe1: display-frontend@01e20000 { + compatible = "allwinner,sun6i-a31-display-frontend"; + reg = <0x01e20000 0x20000>; + interrupts = <GIC_SPI 94 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&ccu CLK_AHB1_FE1>, <&ccu CLK_FE1>, + <&ccu CLK_DRAM_FE1>; + clock-names = "ahb", "mod", + "ram"; + resets = <&ccu RST_AHB1_FE1>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + fe1_out: port@1 { + #address-cells = <1>; + #size-cells = <0>; + reg = <1>; + + fe1_out_be0: endpoint@0 { + reg = <0>; + remote-endpoint = <&be0_in_fe1>; + }; + + fe1_out_be1: endpoint@1 { + reg = <1>; + remote-endpoint = <&be1_in_fe1>; + }; + }; + }; + }; + + be1: display-backend@01e40000 { + compatible = "allwinner,sun6i-a31-display-backend"; + reg = <0x01e40000 0x10000>; + interrupts = <GIC_SPI 96 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&ccu CLK_AHB1_BE1>, <&ccu CLK_BE1>, + <&ccu CLK_DRAM_BE1>; + clock-names = "ahb", "mod", + "ram"; + resets = <&ccu RST_AHB1_BE1>; + + assigned-clocks = <&ccu CLK_BE1>; + assigned-clock-rates = <300000000>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + be1_in: port@0 { + #address-cells = <1>; + #size-cells = <0>; + reg = <0>; + + be1_in_fe0: endpoint@0 { + reg = <0>; + remote-endpoint = <&fe0_out_be1>; + }; + + be1_in_fe1: endpoint@1 { + reg = <1>; + remote-endpoint = <&fe1_out_be1>; + }; + }; + + be1_out: port@1 { + #address-cells = <1>; + #size-cells = <0>; + reg = <1>; + + be1_out_drc1: endpoint@0 { + reg = <0>; + remote-endpoint = <&drc1_in_be1>; + }; + }; + }; + }; + + drc1: drc@01e50000 { + compatible = "allwinner,sun6i-a31-drc"; + reg = <0x01e50000 0x10000>; + interrupts = <GIC_SPI 91 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&ccu CLK_AHB1_DRC1>, <&ccu CLK_IEP_DRC1>, + <&ccu CLK_DRAM_DRC1>; + clock-names = "ahb", "mod", + "ram"; + resets = <&ccu RST_AHB1_DRC1>; + + assigned-clocks = <&ccu CLK_IEP_DRC1>; + assigned-clock-rates = <300000000>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + drc1_in: port@0 { + #address-cells = <1>; + #size-cells = <0>; + reg = <0>; + + drc1_in_be1: endpoint@0 { + reg = <0>; + remote-endpoint = <&be1_out_drc1>; + }; + }; + + drc1_out: port@1 { + #address-cells = <1>; + #size-cells = <0>; + reg = <1>; + + drc1_out_tcon1: endpoint@0 { + reg = <0>; + remote-endpoint = <&tcon1_in_drc1>; + }; }; }; }; @@ -926,6 +1087,11 @@ reg = <0>; remote-endpoint = <&fe0_out_be0>; }; + + be0_in_fe1: endpoint@1 { + reg = <1>; + remote-endpoint = <&fe1_out_be0>; + }; };

be0_out: port@1 {