[PATCH v3 41/41] drm: renesas: shmobile: Add DT support

From: Geert Uytterhoeven
Date: Wed Aug 16 2023 - 06:45:35 EST

Add DT support, by:
1. Creating a panel bridge from DT, and attaching it to the encoder,
2. Replacing the custom connector with a bridge connector,
3. Obtaining clock configuration based on the compatible value.

Note that for now the driver uses a fixed clock configuration selecting
the bus clock, as the current code to select other clock inputs needs
changes to support any other SoCs than SH7724.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
v3:
- No changes,

v2:
- Use devm_drm_of_get_bridge(),
- Don't print bridge->of_node on failure, as this field depends on
CONFIG_OF.

Notes:
- SH-Mobile AG5 (SH73A0) support is untested.
- Unbind crashes when drm_encoder_cleanup() calls drm_bridge_detach(),
as the bridge (allocated by devm_drm_panel_bridge_add()) has already
been freed by that time. This is a known issue with the bridge code.
---
.../gpu/drm/renesas/shmobile/shmob_drm_crtc.c | 56 ++++++++++++++-----
.../gpu/drm/renesas/shmobile/shmob_drm_crtc.h | 1 +
.../gpu/drm/renesas/shmobile/shmob_drm_drv.c | 27 ++++++++-
.../gpu/drm/renesas/shmobile/shmob_drm_drv.h | 6 ++
4 files changed, 74 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
index 729028a15efae00c..2e2f37b9d0a4bafa 100644
--- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
+++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.c
@@ -9,12 +9,16 @@

#include <linux/clk.h>
#include <linux/media-bus-format.h>
+#include <linux/of.h>
+#include <linux/of_graph.h>
#include <linux/pm_runtime.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_atomic_state_helper.h>
#include <drm/drm_atomic_uapi.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_dma_helper.h>
@@ -23,6 +27,7 @@
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_modeset_helper.h>
#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_panel.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_vblank.h>
@@ -35,10 +40,6 @@
#include "shmob_drm_plane.h"
#include "shmob_drm_regs.h"

-/*
- * TODO: panel support
- */
-
/* -----------------------------------------------------------------------------
* Page Flip
*/
@@ -201,7 +202,7 @@ static void shmob_drm_crtc_atomic_enable(struct drm_crtc *crtc,
{
struct shmob_drm_crtc *scrtc = to_shmob_crtc(crtc);
struct shmob_drm_device *sdev = to_shmob_device(crtc->dev);
- const struct shmob_drm_interface_data *idata = &sdev->pdata->iface;
+ unsigned int clk_div = sdev->config.clk_div;
struct device *dev = sdev->dev;
u32 value;
int ret;
@@ -223,17 +224,17 @@ static void shmob_drm_crtc_atomic_enable(struct drm_crtc *crtc,
lcdc_write(sdev, LDPMR, 0);

value = sdev->lddckr;
- if (idata->clk_div) {
+ if (clk_div) {
/* FIXME: sh7724 can only use 42, 48, 54 and 60 for the divider
* denominator.
*/
lcdc_write(sdev, LDDCKPAT1R, 0);
- lcdc_write(sdev, LDDCKPAT2R, (1 << (idata->clk_div / 2)) - 1);
+ lcdc_write(sdev, LDDCKPAT2R, (1 << (clk_div / 2)) - 1);

- if (idata->clk_div == 1)
+ if (clk_div == 1)
value |= LDDCKR_MOSEL;
else
- value |= idata->clk_div;
+ value |= clk_div;
}

lcdc_write(sdev, LDDCKR, value);
@@ -406,7 +407,7 @@ int shmob_drm_crtc_create(struct shmob_drm_device *sdev)
}

/* -----------------------------------------------------------------------------
- * Encoder
+ * Legacy Encoder
*/

static bool shmob_drm_encoder_mode_fixup(struct drm_encoder *encoder,
@@ -435,9 +436,14 @@ static const struct drm_encoder_helper_funcs encoder_helper_funcs = {
.mode_fixup = shmob_drm_encoder_mode_fixup,
};

+/* -----------------------------------------------------------------------------
+ * Encoder
+ */
+
int shmob_drm_encoder_create(struct shmob_drm_device *sdev)
{
struct drm_encoder *encoder = &sdev->encoder;
+ struct drm_bridge *bridge;
int ret;

encoder->possible_crtcs = 1;
@@ -447,13 +453,30 @@ int shmob_drm_encoder_create(struct shmob_drm_device *sdev)
if (ret < 0)
return ret;

- drm_encoder_helper_add(encoder, &encoder_helper_funcs);
+ if (sdev->pdata) {
+ drm_encoder_helper_add(encoder, &encoder_helper_funcs);
+ return 0;
+ }
+
+ /* Create a panel bridge */
+ bridge = devm_drm_of_get_bridge(sdev->dev, sdev->dev->of_node, 0, 0);
+ if (IS_ERR(bridge))
+ return PTR_ERR(bridge);
+
+ /* Attach the bridge to the encoder */
+ ret = drm_bridge_attach(encoder, bridge, NULL,
+ DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+ if (ret) {
+ dev_err(sdev->dev, "failed to attach bridge: %pe\n",
+ ERR_PTR(ret));
+ return ret;
+ }

return 0;
}

/* -----------------------------------------------------------------------------
- * Connector
+ * Legacy Connector
*/

static inline struct shmob_drm_connector *to_shmob_connector(struct drm_connector *connector)
@@ -563,13 +586,20 @@ shmob_drm_connector_init(struct shmob_drm_device *sdev,
return connector;
}

+/* -----------------------------------------------------------------------------
+ * Connector
+ */
+
int shmob_drm_connector_create(struct shmob_drm_device *sdev,
struct drm_encoder *encoder)
{
struct drm_connector *connector;
int ret;

- connector = shmob_drm_connector_init(sdev, encoder);
+ if (sdev->pdata)
+ connector = shmob_drm_connector_init(sdev, encoder);
+ else
+ connector = drm_bridge_connector_init(&sdev->ddev, encoder);
if (IS_ERR(connector)) {
dev_err(sdev->dev, "failed to created connector: %pe\n",
connector);
diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.h b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.h
index 89a0746f9a35807d..16e1712dd04e0f2b 100644
--- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.h
+++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_crtc.h
@@ -29,6 +29,7 @@ struct shmob_drm_crtc {
wait_queue_head_t flip_wait;
};

+/* Legacy connector */
struct shmob_drm_connector {
struct drm_connector base;
struct drm_encoder *encoder;
diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.c b/drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.c
index 58a16efde4e3cb4f..c1833d4b28652cbf 100644
--- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.c
+++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.c
@@ -11,6 +11,7 @@
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
@@ -174,11 +175,13 @@ static int shmob_drm_remove(struct platform_device *pdev)
static int shmob_drm_probe(struct platform_device *pdev)
{
struct shmob_drm_platform_data *pdata = pdev->dev.platform_data;
+ const struct shmob_drm_config *config;
struct shmob_drm_device *sdev;
struct drm_device *ddev;
int ret;

- if (pdata == NULL) {
+ config = of_device_get_match_data(&pdev->dev);
+ if (!config && !pdata) {
dev_err(&pdev->dev, "no platform data\n");
return -EINVAL;
}
@@ -194,7 +197,13 @@ static int shmob_drm_probe(struct platform_device *pdev)

ddev = &sdev->ddev;
sdev->dev = &pdev->dev;
- sdev->pdata = pdata;
+ if (config) {
+ sdev->config = *config;
+ } else {
+ sdev->pdata = pdata;
+ sdev->config.clk_source = pdata->clk_source;
+ sdev->config.clk_div = pdata->iface.clk_div;
+ }
spin_lock_init(&sdev->irq_lock);

platform_set_drvdata(pdev, sdev);
@@ -203,7 +212,7 @@ static int shmob_drm_probe(struct platform_device *pdev)
if (IS_ERR(sdev->mmio))
return PTR_ERR(sdev->mmio);

- ret = shmob_drm_setup_clocks(sdev, pdata->clk_source);
+ ret = shmob_drm_setup_clocks(sdev, sdev->config.clk_source);
if (ret < 0)
return ret;

@@ -251,11 +260,23 @@ static int shmob_drm_probe(struct platform_device *pdev)
return ret;
}

+static const struct shmob_drm_config shmob_arm_config = {
+ .clk_source = SHMOB_DRM_CLK_BUS,
+ .clk_div = 5,
+};
+
+static const struct of_device_id shmob_drm_of_table[] __maybe_unused = {
+ { .compatible = "renesas,r8a7740-lcdc", .data = &shmob_arm_config, },
+ { .compatible = "renesas,sh73a0-lcdc", .data = &shmob_arm_config, },
+ { /* sentinel */ }
+};
+
static struct platform_driver shmob_drm_platform_driver = {
.probe = shmob_drm_probe,
.remove = shmob_drm_remove,
.driver = {
.name = "shmob-drm",
+ .of_match_table = of_match_ptr(shmob_drm_of_table),
.pm = &shmob_drm_pm_ops,
},
};
diff --git a/drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.h b/drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.h
index 18907e5ace51c681..088ac5381e91e61a 100644
--- a/drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.h
+++ b/drivers/gpu/drm/renesas/shmobile/shmob_drm_drv.h
@@ -20,9 +20,15 @@ struct clk;
struct device;
struct drm_device;

+struct shmob_drm_config {
+ enum shmob_drm_clk_source clk_source;
+ unsigned int clk_div;
+};
+
struct shmob_drm_device {
struct device *dev;
const struct shmob_drm_platform_data *pdata;
+ struct shmob_drm_config config;

void __iomem *mmio;
struct clk *clock;
--
2.34.1