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authorMaxime Ripard <maxime.ripard@free-electrons.com>2016-09-06 15:23:03 +0200
committerMaxime Ripard <maxime.ripard@free-electrons.com>2016-09-08 09:29:42 +0200
commit440d2c7b127a8b3aab21eb140262bb29c4ee804f (patch)
tree3829fa7194f4c28c7f40baef78ac047ca80635ca
parent4a408f1f639bd702cc2699d33161f3590c942c2c (diff)
drm/sun4i: backend: Handle the SAT
The A33 has an block called SAT that is part of the backend that needs to be clocked and out of reset to be able for the backend to operate properly. Extend the binding to have the SAT resources listed, and claim them when the backend probes. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Chen-Yu Tsai <wens@csie.org>
-rw-r--r--Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt8
-rw-r--r--drivers/gpu/drm/sun4i/sun4i_backend.c60
-rw-r--r--drivers/gpu/drm/sun4i/sun4i_backend.h3
3 files changed, 71 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
index 46d8c57..abe9e9d 100644
--- a/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
+++ b/Documentation/devicetree/bindings/display/sunxi/sun4i-drm.txt
@@ -76,6 +76,14 @@ Required properties:
Documentation/devicetree/bindings/media/video-interfaces.txt. The
first port should be the input endpoints, the second one the output
+On the A33, some additional properties are required:
+ - reg needs to have an additional region corresponding to the SAT
+ - reg-names need to be set, with "be" and "sat"
+ - clocks and clock-names need to have a phandle to the SAT bus
+ clocks, whose name will be "sat"
+ - resets and reset-names need to have a phandle to the SAT bus
+ resets, whose name will be "sat"
+
Display Engine Frontend
-----------------------
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index 9bfd2e4..91a7022 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -217,6 +217,51 @@ int sun4i_backend_update_layer_buffer(struct sun4i_backend *backend,
}
EXPORT_SYMBOL(sun4i_backend_update_layer_buffer);
+static int sun4i_backend_init_sat(struct device *dev) {
+ struct sun4i_backend *backend = dev_get_drvdata(dev);
+ int ret;
+
+ backend->sat_reset = devm_reset_control_get(dev, "sat");
+ if (IS_ERR(backend->sat_reset)) {
+ dev_err(dev, "Couldn't get the SAT reset line\n");
+ return PTR_ERR(backend->sat_reset);
+ }
+
+ ret = reset_control_deassert(backend->sat_reset);
+ if (ret) {
+ dev_err(dev, "Couldn't deassert the SAT reset line\n");
+ return ret;
+ }
+
+ backend->sat_clk = devm_clk_get(dev, "sat");
+ if (IS_ERR(backend->sat_clk)) {
+ dev_err(dev, "Couldn't get our SAT clock\n");
+ ret = PTR_ERR(backend->sat_clk);
+ goto err_assert_reset;
+ }
+
+ ret = clk_prepare_enable(backend->sat_clk);
+ if (ret) {
+ dev_err(dev, "Couldn't enable the SAT clock\n");
+ return ret;
+ }
+
+ return 0;
+
+err_assert_reset:
+ reset_control_assert(backend->sat_reset);
+ return ret;
+}
+
+static int sun4i_backend_free_sat(struct device *dev) {
+ struct sun4i_backend *backend = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(backend->sat_clk);
+ reset_control_assert(backend->sat_reset);
+
+ return 0;
+}
+
static struct regmap_config sun4i_backend_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
@@ -291,6 +336,15 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
}
clk_prepare_enable(backend->ram_clk);
+ if (of_device_is_compatible(dev->of_node,
+ "allwinner,sun8i-a33-display-backend")) {
+ ret = sun4i_backend_init_sat(dev);
+ if (ret) {
+ dev_err(dev, "Couldn't init SAT resources\n");
+ goto err_disable_ram_clk;
+ }
+ }
+
/* Reset the registers */
for (i = 0x800; i < 0x1000; i += 4)
regmap_write(backend->regs, i, 0);
@@ -306,6 +360,8 @@ static int sun4i_backend_bind(struct device *dev, struct device *master,
return 0;
+err_disable_ram_clk:
+ clk_disable_unprepare(backend->ram_clk);
err_disable_mod_clk:
clk_disable_unprepare(backend->mod_clk);
err_disable_bus_clk:
@@ -320,6 +376,10 @@ static void sun4i_backend_unbind(struct device *dev, struct device *master,
{
struct sun4i_backend *backend = dev_get_drvdata(dev);
+ if (of_device_is_compatible(dev->of_node,
+ "allwinner,sun8i-a33-display-backend"))
+ sun4i_backend_free_sat(dev);
+
clk_disable_unprepare(backend->ram_clk);
clk_disable_unprepare(backend->mod_clk);
clk_disable_unprepare(backend->bus_clk);
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.h b/drivers/gpu/drm/sun4i/sun4i_backend.h
index 7070bb3..e007186 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.h
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.h
@@ -146,6 +146,9 @@ struct sun4i_backend {
struct clk *bus_clk;
struct clk *mod_clk;
struct clk *ram_clk;
+
+ struct clk *sat_clk;
+ struct reset_control *sat_reset;
};
void sun4i_backend_apply_color_correction(struct sun4i_backend *backend);