| Message ID | 20240417024137.144727-3-dharma.b@microchip.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | LVDS Controller Support for SAM9X75 SoC | expand |
On Wed, Apr 17, 2024 at 08:11:35AM +0530, Dharma Balasubiramani wrote: > Add a new LVDS controller driver for sam9x7 which does the following: > - Prepares and enables the LVDS Peripheral clock > - Defines its connector type as DRM_MODE_CONNECTOR_LVDS and adds itself > to the global bridge list. > - Identifies its output endpoint as panel and adds it to the encoder > display pipeline > - Enables the LVDS serializer > > Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com> > Signed-off-by: Dharma Balasubiramani <dharma.b@microchip.com> > --- > Changelog > v5 -> v6 > - No Changes. > v4 -> v5 > - Drop the unused variable 'format'. > - Use DRM wrapper for dev_err() to maintain uniformity. > - return -ENODEV instead of -EINVAL to maintain consistency with other DRM > bridge drivers. > v3 -> v4 > - No changes. > v2 ->v3 > - Correct Typo error "serializer". > - Consolidate get() and prepare() functions and use devm_clk_get_prepared(). > - Remove unused variable 'ret' in probe(). > - Use devm_pm_runtime_enable() and drop the mchp_lvds_remove(). > v1 -> v2 > - Drop 'res' variable and combine two lines into one. > - Handle deferred probe properly, use dev_err_probe(). > - Don't print anything on deferred probe. Dropped print. > - Remove the MODULE_ALIAS and add MODULE_DEVICE_TABLE(). > - symbol 'mchp_lvds_driver' was not declared. It should be static. > --- > drivers/gpu/drm/bridge/Kconfig | 7 + > drivers/gpu/drm/bridge/Makefile | 1 + > drivers/gpu/drm/bridge/microchip-lvds.c | 228 ++++++++++++++++++++++++ > 3 files changed, 236 insertions(+) > create mode 100644 drivers/gpu/drm/bridge/microchip-lvds.c > > diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig > index efd996f6c138..889098e2d65f 100644 > --- a/drivers/gpu/drm/bridge/Kconfig > +++ b/drivers/gpu/drm/bridge/Kconfig > @@ -190,6 +190,13 @@ config DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW > to DP++. This is used with the i.MX6 imx-ldb > driver. You are likely to say N here. > > +config DRM_MICROCHIP_LVDS_SERIALIZER > + tristate "Microchip LVDS serializer support" > + depends on OF > + depends on DRM_ATMEL_HLCDC > + help > + Support for Microchip's LVDS serializer. > + > config DRM_NWL_MIPI_DSI > tristate "Northwest Logic MIPI DSI Host controller" > depends on DRM > diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile > index 017b5832733b..7df87b582dca 100644 > --- a/drivers/gpu/drm/bridge/Makefile > +++ b/drivers/gpu/drm/bridge/Makefile > @@ -13,6 +13,7 @@ obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o > obj-$(CONFIG_DRM_LONTIUM_LT9611UXC) += lontium-lt9611uxc.o > obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o > obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o > +obj-$(CONFIG_DRM_MICROCHIP_LVDS_SERIALIZER) += microchip-lvds.o > obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o > obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o > obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o > diff --git a/drivers/gpu/drm/bridge/microchip-lvds.c b/drivers/gpu/drm/bridge/microchip-lvds.c > new file mode 100644 > index 000000000000..149704f498a6 > --- /dev/null > +++ b/drivers/gpu/drm/bridge/microchip-lvds.c > @@ -0,0 +1,228 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2023 Microchip Technology Inc. and its subsidiaries > + * > + * Author: Manikandan Muralidharan <manikandan.m@microchip.com> > + * Author: Dharma Balasubiramani <dharma.b@microchip.com> > + * > + */ > + > +#include <linux/clk.h> > +#include <linux/component.h> > +#include <linux/delay.h> > +#include <linux/jiffies.h> > +#include <linux/mfd/syscon.h> > +#include <linux/of_graph.h> > +#include <linux/pinctrl/devinfo.h> > +#include <linux/phy/phy.h> > +#include <linux/platform_device.h> > +#include <linux/pm_runtime.h> > +#include <linux/regmap.h> > +#include <linux/reset.h> > + > +#include <drm/drm_atomic_helper.h> > +#include <drm/drm_bridge.h> > +#include <drm/drm_of.h> > +#include <drm/drm_panel.h> > +#include <drm/drm_print.h> > +#include <drm/drm_probe_helper.h> > +#include <drm/drm_simple_kms_helper.h> > + > +#define LVDS_POLL_TIMEOUT_MS 1000 > + > +/* LVDSC register offsets */ > +#define LVDSC_CR 0x00 > +#define LVDSC_CFGR 0x04 > +#define LVDSC_SR 0x0C > +#define LVDSC_WPMR 0xE4 > + > +/* Bitfields in LVDSC_CR (Control Register) */ > +#define LVDSC_CR_SER_EN BIT(0) > + > +/* Bitfields in LVDSC_CFGR (Configuration Register) */ > +#define LVDSC_CFGR_PIXSIZE_24BITS 0 > +#define LVDSC_CFGR_DEN_POL_HIGH 0 > +#define LVDSC_CFGR_DC_UNBALANCED 0 > +#define LVDSC_CFGR_MAPPING_JEIDA BIT(6) > + > +/*Bitfields in LVDSC_SR */ > +#define LVDSC_SR_CS BIT(0) > + > +/* Bitfields in LVDSC_WPMR (Write Protection Mode Register) */ > +#define LVDSC_WPMR_WPKEY_MASK GENMASK(31, 8) > +#define LVDSC_WPMR_WPKEY_PSSWD 0x4C5644 > + > +struct mchp_lvds { > + struct device *dev; > + void __iomem *regs; > + struct clk *pclk; > + struct drm_panel *panel; > + struct drm_bridge bridge; > + struct drm_bridge *panel_bridge; > +}; > + > +static inline struct mchp_lvds *bridge_to_lvds(struct drm_bridge *bridge) > +{ > + return container_of(bridge, struct mchp_lvds, bridge); > +} > + > +static inline u32 lvds_readl(struct mchp_lvds *lvds, u32 offset) > +{ > + return readl_relaxed(lvds->regs + offset); > +} > + > +static inline void lvds_writel(struct mchp_lvds *lvds, u32 offset, u32 val) > +{ > + writel_relaxed(val, lvds->regs + offset); > +} > + > +static void lvds_serialiser_on(struct mchp_lvds *lvds) > +{ > + unsigned long timeout = jiffies + msecs_to_jiffies(LVDS_POLL_TIMEOUT_MS); > + > + /* The LVDSC registers can only be written if WPEN is cleared */ > + lvds_writel(lvds, LVDSC_WPMR, (LVDSC_WPMR_WPKEY_PSSWD & > + LVDSC_WPMR_WPKEY_MASK)); > + > + /* Wait for the status of configuration registers to be changed */ > + while (lvds_readl(lvds, LVDSC_SR) & LVDSC_SR_CS) { > + if (time_after(jiffies, timeout)) { > + DRM_DEV_ERROR(lvds->dev, "%s: timeout error\n", > + __func__); > + return; > + } > + usleep_range(1000, 2000); > + } > + > + /* Configure the LVDSC */ > + lvds_writel(lvds, LVDSC_CFGR, (LVDSC_CFGR_MAPPING_JEIDA | > + LVDSC_CFGR_DC_UNBALANCED | > + LVDSC_CFGR_DEN_POL_HIGH | > + LVDSC_CFGR_PIXSIZE_24BITS)); > + > + /* Enable the LVDS serializer */ > + lvds_writel(lvds, LVDSC_CR, LVDSC_CR_SER_EN); > +} > + > +static int mchp_lvds_attach(struct drm_bridge *bridge, > + enum drm_bridge_attach_flags flags) > +{ > + struct mchp_lvds *lvds = bridge_to_lvds(bridge); > + > + bridge->encoder->encoder_type = DRM_MODE_ENCODER_LVDS; Why do you need to touch encoder_type here? It's not your bridge's responsibility. > + > + return drm_bridge_attach(bridge->encoder, lvds->panel_bridge, > + bridge, flags); > +} > + > +static void mchp_lvds_enable(struct drm_bridge *bridge) > +{ > + struct mchp_lvds *lvds = bridge_to_lvds(bridge); > + int ret; > + > + ret = clk_enable(lvds->pclk); > + if (ret < 0) { > + DRM_DEV_ERROR(lvds->dev, "failed to enable lvds pclk %d\n", ret); > + return; > + } > + > + ret = pm_runtime_get_sync(lvds->dev); > + if (ret < 0) { > + DRM_DEV_ERROR(lvds->dev, "failed to get pm runtime: %d\n", ret); > + clk_disable(lvds->pclk); This can result in unbalanced clk_disable(), if pm_runtime_get_sync() fails. This function calls clk_disable(), but the framework has no way to know that .enable() was not successful and calls .disable(), which also calls clk_disable(). Please consider turning pclk into pm_clk so that its state is managed automatically (or at least moving clk_enable/disable into pm_ops). > + return; > + } > + > + lvds_serialiser_on(lvds); > +} > + > +static void mchp_lvds_disable(struct drm_bridge *bridge) > +{ > + struct mchp_lvds *lvds = bridge_to_lvds(bridge); > + > + pm_runtime_put(lvds->dev); > + clk_disable(lvds->pclk); > +} > + > +static const struct drm_bridge_funcs mchp_lvds_bridge_funcs = { > + .attach = mchp_lvds_attach, > + .enable = mchp_lvds_enable, > + .disable = mchp_lvds_disable, > +}; > + > +static int mchp_lvds_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct mchp_lvds *lvds; > + struct device_node *port; > + > + if (!dev->of_node) > + return -ENODEV; > + > + lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL); > + if (!lvds) > + return -ENOMEM; > + > + lvds->dev = dev; > + > + lvds->regs = devm_ioremap_resource(lvds->dev, > + platform_get_resource(pdev, IORESOURCE_MEM, 0)); > + if (IS_ERR(lvds->regs)) > + return PTR_ERR(lvds->regs); > + > + lvds->pclk = devm_clk_get_prepared(lvds->dev, "pclk"); Why do you need _prepared version? > + if (IS_ERR(lvds->pclk)) > + return dev_err_probe(lvds->dev, PTR_ERR(lvds->pclk), > + "could not get pclk_lvds prepared\n"); > + > + port = of_graph_get_remote_node(dev->of_node, 1, 0); > + if (!port) { > + DRM_DEV_ERROR(dev, > + "can't find port point, please init lvds panel port!\n"); > + return -ENODEV; > + } > + > + lvds->panel = of_drm_find_panel(port); > + of_node_put(port); > + > + if (IS_ERR(lvds->panel)) > + return -EPROBE_DEFER; > + > + lvds->panel_bridge = devm_drm_panel_bridge_add(dev, lvds->panel); Please use instead: devm_drm_of_get_bridge(dev, dev->of_node, 1, 0); > + > + if (IS_ERR(lvds->panel_bridge)) > + return PTR_ERR(lvds->panel_bridge); > + > + lvds->bridge.of_node = dev->of_node; > + lvds->bridge.type = DRM_MODE_CONNECTOR_LVDS; > + lvds->bridge.funcs = &mchp_lvds_bridge_funcs; > + > + dev_set_drvdata(dev, lvds); > + devm_pm_runtime_enable(dev); Error check is missing. > + > + drm_bridge_add(&lvds->bridge); > + > + return 0; > +} > + > +static const struct of_device_id mchp_lvds_dt_ids[] = { > + { > + .compatible = "microchip,sam9x75-lvds", > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, mchp_lvds_dt_ids); > + > +static struct platform_driver mchp_lvds_driver = { > + .probe = mchp_lvds_probe, > + .driver = { > + .name = "microchip-lvds", > + .of_match_table = mchp_lvds_dt_ids, > + }, > +}; > +module_platform_driver(mchp_lvds_driver); > + > +MODULE_AUTHOR("Manikandan Muralidharan <manikandan.m@microchip.com>"); > +MODULE_AUTHOR("Dharma Balasubiramani <dharma.b@microchip.com>"); > +MODULE_DESCRIPTION("Low Voltage Differential Signaling Controller Driver"); > +MODULE_LICENSE("GPL"); > -- > 2.25.1 >
Hi Dmitry, On 17/04/24 12:05 pm, Dmitry Baryshkov wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > On Wed, Apr 17, 2024 at 08:11:35AM +0530, Dharma Balasubiramani wrote: >> Add a new LVDS controller driver for sam9x7 which does the following: >> - Prepares and enables the LVDS Peripheral clock >> - Defines its connector type as DRM_MODE_CONNECTOR_LVDS and adds itself >> to the global bridge list. >> - Identifies its output endpoint as panel and adds it to the encoder >> display pipeline >> - Enables the LVDS serializer >> >> Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com> >> Signed-off-by: Dharma Balasubiramani <dharma.b@microchip.com> >> --- >> Changelog >> v5 -> v6 >> - No Changes. >> v4 -> v5 >> - Drop the unused variable 'format'. >> - Use DRM wrapper for dev_err() to maintain uniformity. >> - return -ENODEV instead of -EINVAL to maintain consistency with other DRM >> bridge drivers. >> v3 -> v4 >> - No changes. >> v2 ->v3 >> - Correct Typo error "serializer". >> - Consolidate get() and prepare() functions and use devm_clk_get_prepared(). >> - Remove unused variable 'ret' in probe(). >> - Use devm_pm_runtime_enable() and drop the mchp_lvds_remove(). >> v1 -> v2 >> - Drop 'res' variable and combine two lines into one. >> - Handle deferred probe properly, use dev_err_probe(). >> - Don't print anything on deferred probe. Dropped print. >> - Remove the MODULE_ALIAS and add MODULE_DEVICE_TABLE(). >> - symbol 'mchp_lvds_driver' was not declared. It should be static. >> --- >> drivers/gpu/drm/bridge/Kconfig | 7 + >> drivers/gpu/drm/bridge/Makefile | 1 + >> drivers/gpu/drm/bridge/microchip-lvds.c | 228 ++++++++++++++++++++++++ >> 3 files changed, 236 insertions(+) >> create mode 100644 drivers/gpu/drm/bridge/microchip-lvds.c >> >> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig >> index efd996f6c138..889098e2d65f 100644 >> --- a/drivers/gpu/drm/bridge/Kconfig >> +++ b/drivers/gpu/drm/bridge/Kconfig >> @@ -190,6 +190,13 @@ config DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW >> to DP++. This is used with the i.MX6 imx-ldb >> driver. You are likely to say N here. >> >> +config DRM_MICROCHIP_LVDS_SERIALIZER >> + tristate "Microchip LVDS serializer support" >> + depends on OF >> + depends on DRM_ATMEL_HLCDC >> + help >> + Support for Microchip's LVDS serializer. >> + >> config DRM_NWL_MIPI_DSI >> tristate "Northwest Logic MIPI DSI Host controller" >> depends on DRM >> diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile >> index 017b5832733b..7df87b582dca 100644 >> --- a/drivers/gpu/drm/bridge/Makefile >> +++ b/drivers/gpu/drm/bridge/Makefile >> @@ -13,6 +13,7 @@ obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o >> obj-$(CONFIG_DRM_LONTIUM_LT9611UXC) += lontium-lt9611uxc.o >> obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o >> obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o >> +obj-$(CONFIG_DRM_MICROCHIP_LVDS_SERIALIZER) += microchip-lvds.o >> obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o >> obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o >> obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o >> diff --git a/drivers/gpu/drm/bridge/microchip-lvds.c b/drivers/gpu/drm/bridge/microchip-lvds.c >> new file mode 100644 >> index 000000000000..149704f498a6 >> --- /dev/null >> +++ b/drivers/gpu/drm/bridge/microchip-lvds.c >> @@ -0,0 +1,228 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Copyright (C) 2023 Microchip Technology Inc. and its subsidiaries >> + * >> + * Author: Manikandan Muralidharan <manikandan.m@microchip.com> >> + * Author: Dharma Balasubiramani <dharma.b@microchip.com> >> + * >> + */ >> + >> +#include <linux/clk.h> >> +#include <linux/component.h> >> +#include <linux/delay.h> >> +#include <linux/jiffies.h> >> +#include <linux/mfd/syscon.h> >> +#include <linux/of_graph.h> >> +#include <linux/pinctrl/devinfo.h> >> +#include <linux/phy/phy.h> >> +#include <linux/platform_device.h> >> +#include <linux/pm_runtime.h> >> +#include <linux/regmap.h> >> +#include <linux/reset.h> >> + >> +#include <drm/drm_atomic_helper.h> >> +#include <drm/drm_bridge.h> >> +#include <drm/drm_of.h> >> +#include <drm/drm_panel.h> >> +#include <drm/drm_print.h> >> +#include <drm/drm_probe_helper.h> >> +#include <drm/drm_simple_kms_helper.h> >> + >> +#define LVDS_POLL_TIMEOUT_MS 1000 >> + >> +/* LVDSC register offsets */ >> +#define LVDSC_CR 0x00 >> +#define LVDSC_CFGR 0x04 >> +#define LVDSC_SR 0x0C >> +#define LVDSC_WPMR 0xE4 >> + >> +/* Bitfields in LVDSC_CR (Control Register) */ >> +#define LVDSC_CR_SER_EN BIT(0) >> + >> +/* Bitfields in LVDSC_CFGR (Configuration Register) */ >> +#define LVDSC_CFGR_PIXSIZE_24BITS 0 >> +#define LVDSC_CFGR_DEN_POL_HIGH 0 >> +#define LVDSC_CFGR_DC_UNBALANCED 0 >> +#define LVDSC_CFGR_MAPPING_JEIDA BIT(6) >> + >> +/*Bitfields in LVDSC_SR */ >> +#define LVDSC_SR_CS BIT(0) >> + >> +/* Bitfields in LVDSC_WPMR (Write Protection Mode Register) */ >> +#define LVDSC_WPMR_WPKEY_MASK GENMASK(31, 8) >> +#define LVDSC_WPMR_WPKEY_PSSWD 0x4C5644 >> + >> +struct mchp_lvds { >> + struct device *dev; >> + void __iomem *regs; >> + struct clk *pclk; >> + struct drm_panel *panel; >> + struct drm_bridge bridge; >> + struct drm_bridge *panel_bridge; >> +}; >> + >> +static inline struct mchp_lvds *bridge_to_lvds(struct drm_bridge *bridge) >> +{ >> + return container_of(bridge, struct mchp_lvds, bridge); >> +} >> + >> +static inline u32 lvds_readl(struct mchp_lvds *lvds, u32 offset) >> +{ >> + return readl_relaxed(lvds->regs + offset); >> +} >> + >> +static inline void lvds_writel(struct mchp_lvds *lvds, u32 offset, u32 val) >> +{ >> + writel_relaxed(val, lvds->regs + offset); >> +} >> + >> +static void lvds_serialiser_on(struct mchp_lvds *lvds) >> +{ >> + unsigned long timeout = jiffies + msecs_to_jiffies(LVDS_POLL_TIMEOUT_MS); >> + >> + /* The LVDSC registers can only be written if WPEN is cleared */ >> + lvds_writel(lvds, LVDSC_WPMR, (LVDSC_WPMR_WPKEY_PSSWD & >> + LVDSC_WPMR_WPKEY_MASK)); >> + >> + /* Wait for the status of configuration registers to be changed */ >> + while (lvds_readl(lvds, LVDSC_SR) & LVDSC_SR_CS) { >> + if (time_after(jiffies, timeout)) { >> + DRM_DEV_ERROR(lvds->dev, "%s: timeout error\n", >> + __func__); >> + return; >> + } >> + usleep_range(1000, 2000); >> + } >> + >> + /* Configure the LVDSC */ >> + lvds_writel(lvds, LVDSC_CFGR, (LVDSC_CFGR_MAPPING_JEIDA | >> + LVDSC_CFGR_DC_UNBALANCED | >> + LVDSC_CFGR_DEN_POL_HIGH | >> + LVDSC_CFGR_PIXSIZE_24BITS)); >> + >> + /* Enable the LVDS serializer */ >> + lvds_writel(lvds, LVDSC_CR, LVDSC_CR_SER_EN); >> +} >> + >> +static int mchp_lvds_attach(struct drm_bridge *bridge, >> + enum drm_bridge_attach_flags flags) >> +{ >> + struct mchp_lvds *lvds = bridge_to_lvds(bridge); >> + >> + bridge->encoder->encoder_type = DRM_MODE_ENCODER_LVDS; > > Why do you need to touch encoder_type here? It's not your bridge's > responsibility. Indeed, I've verified it across other bridge drivers too. Thank you for bringing it to my attention. I will remove setting the encoder type here. > >> + >> + return drm_bridge_attach(bridge->encoder, lvds->panel_bridge, >> + bridge, flags); >> +} >> + >> +static void mchp_lvds_enable(struct drm_bridge *bridge) >> +{ >> + struct mchp_lvds *lvds = bridge_to_lvds(bridge); >> + int ret; >> + >> + ret = clk_enable(lvds->pclk); I will change this into clk_prepare_enable as we are dropping the prepared version in the probe(). >> + if (ret < 0) { >> + DRM_DEV_ERROR(lvds->dev, "failed to enable lvds pclk %d\n", ret); >> + return; >> + } >> + >> + ret = pm_runtime_get_sync(lvds->dev); >> + if (ret < 0) { >> + DRM_DEV_ERROR(lvds->dev, "failed to get pm runtime: %d\n", ret); >> + clk_disable(lvds->pclk); > > This can result in unbalanced clk_disable(), if pm_runtime_get_sync() > fails. This function calls clk_disable(), but the framework has no way > to know that .enable() was not successful and calls .disable(), which > also calls clk_disable( > > Please consider turning pclk into pm_clk so that its state is managed > automatically (or at least moving clk_enable/disable into pm_ops). This process appears rather intricate. May I suggest omitting the 'clk_disable' operation here? > >> + return; >> + } >> + >> + lvds_serialiser_on(lvds); >> +} >> + >> +static void mchp_lvds_disable(struct drm_bridge *bridge) >> +{ >> + struct mchp_lvds *lvds = bridge_to_lvds(bridge); >> + >> + pm_runtime_put(lvds->dev); >> + clk_disable(lvds->pclk); >> +} >> + >> +static const struct drm_bridge_funcs mchp_lvds_bridge_funcs = { >> + .attach = mchp_lvds_attach, >> + .enable = mchp_lvds_enable, >> + .disable = mchp_lvds_disable, >> +}; >> + >> +static int mchp_lvds_probe(struct platform_device *pdev) >> +{ >> + struct device *dev = &pdev->dev; >> + struct mchp_lvds *lvds; >> + struct device_node *port; >> + >> + if (!dev->of_node) >> + return -ENODEV; >> + >> + lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL); >> + if (!lvds) >> + return -ENOMEM; >> + >> + lvds->dev = dev; >> + >> + lvds->regs = devm_ioremap_resource(lvds->dev, >> + platform_get_resource(pdev, IORESOURCE_MEM, 0)); >> + if (IS_ERR(lvds->regs)) >> + return PTR_ERR(lvds->regs); >> + >> + lvds->pclk = devm_clk_get_prepared(lvds->dev, "pclk"); > > Why do you need _prepared version? I will change this to just devm_clk_get(). > >> + if (IS_ERR(lvds->pclk)) >> + return dev_err_probe(lvds->dev, PTR_ERR(lvds->pclk), >> + "could not get pclk_lvds prepared\n"); >> + >> + port = of_graph_get_remote_node(dev->of_node, 1, 0); >> + if (!port) { >> + DRM_DEV_ERROR(dev, >> + "can't find port point, please init lvds panel port!\n"); >> + return -ENODEV; >> + } >> + >> + lvds->panel = of_drm_find_panel(port); >> + of_node_put(port); >> + >> + if (IS_ERR(lvds->panel)) >> + return -EPROBE_DEFER; >> + >> + lvds->panel_bridge = devm_drm_panel_bridge_add(dev, lvds->panel); > > Please use instead: > > devm_drm_of_get_bridge(dev, dev->of_node, 1, 0); Sure, Noted. Thanks. > >> + >> + if (IS_ERR(lvds->panel_bridge)) >> + return PTR_ERR(lvds->panel_bridge); >> + >> + lvds->bridge.of_node = dev->of_node; >> + lvds->bridge.type = DRM_MODE_CONNECTOR_LVDS; >> + lvds->bridge.funcs = &mchp_lvds_bridge_funcs; >> + >> + dev_set_drvdata(dev, lvds); >> + devm_pm_runtime_enable(dev); > > Error check is missing. Sure, I will add this ret = devm_pm_runtime_enable(dev); if (ret < 0) { DRM_DEV_ERROR(lvds->dev, "failed to enable pm runtime: %d\n", ret); return ret; } > >> + >> + drm_bridge_add(&lvds->bridge); >> + >> + return 0; >> +} >> + >> +static const struct of_device_id mchp_lvds_dt_ids[] = { >> + { >> + .compatible = "microchip,sam9x75-lvds", >> + }, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, mchp_lvds_dt_ids); >> + >> +static struct platform_driver mchp_lvds_driver = { >> + .probe = mchp_lvds_probe, >> + .driver = { >> + .name = "microchip-lvds", >> + .of_match_table = mchp_lvds_dt_ids, >> + }, >> +}; >> +module_platform_driver(mchp_lvds_driver); >> + >> +MODULE_AUTHOR("Manikandan Muralidharan <manikandan.m@microchip.com>"); >> +MODULE_AUTHOR("Dharma Balasubiramani <dharma.b@microchip.com>"); >> +MODULE_DESCRIPTION("Low Voltage Differential Signaling Controller Driver"); >> +MODULE_LICENSE("GPL"); >> -- >> 2.25.1 >> > > -- > With best wishes > Dmitry
On Thu, Apr 18, 2024 at 03:54:53AM +0000, Dharma.B@microchip.com wrote: > Hi Dmitry, > > On 17/04/24 12:05 pm, Dmitry Baryshkov wrote: > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > > > On Wed, Apr 17, 2024 at 08:11:35AM +0530, Dharma Balasubiramani wrote: > >> Add a new LVDS controller driver for sam9x7 which does the following: > >> - Prepares and enables the LVDS Peripheral clock > >> - Defines its connector type as DRM_MODE_CONNECTOR_LVDS and adds itself > >> to the global bridge list. > >> - Identifies its output endpoint as panel and adds it to the encoder > >> display pipeline > >> - Enables the LVDS serializer > >> > >> Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com> > >> Signed-off-by: Dharma Balasubiramani <dharma.b@microchip.com> > >> --- > >> Changelog > >> v5 -> v6 > >> - No Changes. > >> v4 -> v5 > >> - Drop the unused variable 'format'. > >> - Use DRM wrapper for dev_err() to maintain uniformity. > >> - return -ENODEV instead of -EINVAL to maintain consistency with other DRM > >> bridge drivers. > >> v3 -> v4 > >> - No changes. > >> v2 ->v3 > >> - Correct Typo error "serializer". > >> - Consolidate get() and prepare() functions and use devm_clk_get_prepared(). > >> - Remove unused variable 'ret' in probe(). > >> - Use devm_pm_runtime_enable() and drop the mchp_lvds_remove(). > >> v1 -> v2 > >> - Drop 'res' variable and combine two lines into one. > >> - Handle deferred probe properly, use dev_err_probe(). > >> - Don't print anything on deferred probe. Dropped print. > >> - Remove the MODULE_ALIAS and add MODULE_DEVICE_TABLE(). > >> - symbol 'mchp_lvds_driver' was not declared. It should be static. > >> --- > >> drivers/gpu/drm/bridge/Kconfig | 7 + > >> drivers/gpu/drm/bridge/Makefile | 1 + > >> drivers/gpu/drm/bridge/microchip-lvds.c | 228 ++++++++++++++++++++++++ > >> 3 files changed, 236 insertions(+) > >> create mode 100644 drivers/gpu/drm/bridge/microchip-lvds.c > >> > >> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig > >> index efd996f6c138..889098e2d65f 100644 > >> --- a/drivers/gpu/drm/bridge/Kconfig > >> +++ b/drivers/gpu/drm/bridge/Kconfig [skipped] > >> + if (ret < 0) { > >> + DRM_DEV_ERROR(lvds->dev, "failed to enable lvds pclk %d\n", ret); > >> + return; > >> + } > >> + > >> + ret = pm_runtime_get_sync(lvds->dev); > >> + if (ret < 0) { > >> + DRM_DEV_ERROR(lvds->dev, "failed to get pm runtime: %d\n", ret); > >> + clk_disable(lvds->pclk); > > > > This can result in unbalanced clk_disable(), if pm_runtime_get_sync() > > fails. This function calls clk_disable(), but the framework has no way > > to know that .enable() was not successful and calls .disable(), which > > also calls clk_disable( > > > Please consider turning pclk into pm_clk so that its state is managed > > automatically (or at least moving clk_enable/disable into pm_ops). > > This process appears rather intricate. May I suggest omitting the > 'clk_disable' operation here? Yes > > > > >> + return; > >> + } > >> + > >> + lvds_serialiser_on(lvds); > >> +} > >> + > >> +static void mchp_lvds_disable(struct drm_bridge *bridge) > >> +{ > >> + struct mchp_lvds *lvds = bridge_to_lvds(bridge); > >> + > >> + pm_runtime_put(lvds->dev); > >> + clk_disable(lvds->pclk); > >> +} > >> + > >> +static const struct drm_bridge_funcs mchp_lvds_bridge_funcs = { > >> + .attach = mchp_lvds_attach, > >> + .enable = mchp_lvds_enable, > >> + .disable = mchp_lvds_disable, > >> +}; > >> + > >> +static int mchp_lvds_probe(struct platform_device *pdev) > >> +{ > >> + struct device *dev = &pdev->dev; > >> + struct mchp_lvds *lvds; > >> + struct device_node *port; > >> + > >> + if (!dev->of_node) > >> + return -ENODEV; > >> + > >> + lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL); > >> + if (!lvds) > >> + return -ENOMEM; > >> + > >> + lvds->dev = dev; > >> + > >> + lvds->regs = devm_ioremap_resource(lvds->dev, > >> + platform_get_resource(pdev, IORESOURCE_MEM, 0)); > >> + if (IS_ERR(lvds->regs)) > >> + return PTR_ERR(lvds->regs); > >> + > >> + lvds->pclk = devm_clk_get_prepared(lvds->dev, "pclk"); > > > > Why do you need _prepared version? > > I will change this to just devm_clk_get(). > > > > >> + if (IS_ERR(lvds->pclk)) > >> + return dev_err_probe(lvds->dev, PTR_ERR(lvds->pclk), > >> + "could not get pclk_lvds prepared\n"); > >> + > >> + port = of_graph_get_remote_node(dev->of_node, 1, 0); > >> + if (!port) { > >> + DRM_DEV_ERROR(dev, > >> + "can't find port point, please init lvds panel port!\n"); > >> + return -ENODEV; > >> + } > >> + > >> + lvds->panel = of_drm_find_panel(port); > >> + of_node_put(port); > >> + > >> + if (IS_ERR(lvds->panel)) > >> + return -EPROBE_DEFER; > >> + > >> + lvds->panel_bridge = devm_drm_panel_bridge_add(dev, lvds->panel); > > > > Please use instead: > > > > devm_drm_of_get_bridge(dev, dev->of_node, 1, 0); > > Sure, Noted. Thanks. > > > >> + > >> + if (IS_ERR(lvds->panel_bridge)) > >> + return PTR_ERR(lvds->panel_bridge); > >> + > >> + lvds->bridge.of_node = dev->of_node; > >> + lvds->bridge.type = DRM_MODE_CONNECTOR_LVDS; > >> + lvds->bridge.funcs = &mchp_lvds_bridge_funcs; > >> + > >> + dev_set_drvdata(dev, lvds); > >> + devm_pm_runtime_enable(dev); > > > > Error check is missing. > > Sure, I will add this > > ret = devm_pm_runtime_enable(dev); > if (ret < 0) { > DRM_DEV_ERROR(lvds->dev, "failed to enable pm runtime: DRM_DEV_ERROR is deprecated, plese use suitable replacement. > %d\n", ret); > return ret; > } > >
On 18/04/24 11:55 am, Dmitry Baryshkov wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > On Thu, Apr 18, 2024 at 03:54:53AM +0000, Dharma.B@microchip.com wrote: >> Hi Dmitry, >> >> On 17/04/24 12:05 pm, Dmitry Baryshkov wrote: >>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe >>> >>> On Wed, Apr 17, 2024 at 08:11:35AM +0530, Dharma Balasubiramani wrote: >>>> Add a new LVDS controller driver for sam9x7 which does the following: >>>> - Prepares and enables the LVDS Peripheral clock >>>> - Defines its connector type as DRM_MODE_CONNECTOR_LVDS and adds itself >>>> to the global bridge list. >>>> - Identifies its output endpoint as panel and adds it to the encoder >>>> display pipeline >>>> - Enables the LVDS serializer >>>> >>>> Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com> >>>> Signed-off-by: Dharma Balasubiramani <dharma.b@microchip.com> >>>> --- >>>> Changelog >>>> v5 -> v6 >>>> - No Changes. >>>> v4 -> v5 >>>> - Drop the unused variable 'format'. >>>> - Use DRM wrapper for dev_err() to maintain uniformity. >>>> - return -ENODEV instead of -EINVAL to maintain consistency with other DRM >>>> bridge drivers. >>>> v3 -> v4 >>>> - No changes. >>>> v2 ->v3 >>>> - Correct Typo error "serializer". >>>> - Consolidate get() and prepare() functions and use devm_clk_get_prepared(). >>>> - Remove unused variable 'ret' in probe(). >>>> - Use devm_pm_runtime_enable() and drop the mchp_lvds_remove(). >>>> v1 -> v2 >>>> - Drop 'res' variable and combine two lines into one. >>>> - Handle deferred probe properly, use dev_err_probe(). >>>> - Don't print anything on deferred probe. Dropped print. >>>> - Remove the MODULE_ALIAS and add MODULE_DEVICE_TABLE(). >>>> - symbol 'mchp_lvds_driver' was not declared. It should be static. >>>> --- >>>> drivers/gpu/drm/bridge/Kconfig | 7 + >>>> drivers/gpu/drm/bridge/Makefile | 1 + >>>> drivers/gpu/drm/bridge/microchip-lvds.c | 228 ++++++++++++++++++++++++ >>>> 3 files changed, 236 insertions(+) >>>> create mode 100644 drivers/gpu/drm/bridge/microchip-lvds.c >>>> >>>> diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig >>>> index efd996f6c138..889098e2d65f 100644 >>>> --- a/drivers/gpu/drm/bridge/Kconfig >>>> +++ b/drivers/gpu/drm/bridge/Kconfig > > [skipped] > >>>> + if (ret < 0) { >>>> + DRM_DEV_ERROR(lvds->dev, "failed to enable lvds pclk %d\n", ret); >>>> + return; >>>> + } >>>> + >>>> + ret = pm_runtime_get_sync(lvds->dev); >>>> + if (ret < 0) { >>>> + DRM_DEV_ERROR(lvds->dev, "failed to get pm runtime: %d\n", ret); >>>> + clk_disable(lvds->pclk); >>> >>> This can result in unbalanced clk_disable(), if pm_runtime_get_sync() >>> fails. This function calls clk_disable(), but the framework has no way >>> to know that .enable() was not successful and calls .disable(), which >>> also calls clk_disable( > >>> Please consider turning pclk into pm_clk so that its state is managed >>> automatically (or at least moving clk_enable/disable into pm_ops). >> >> This process appears rather intricate. May I suggest omitting the >> 'clk_disable' operation here? > > Yes > >> >>> >>>> + return; >>>> + } >>>> + >>>> + lvds_serialiser_on(lvds); >>>> +} >>>> + >>>> +static void mchp_lvds_disable(struct drm_bridge *bridge) >>>> +{ >>>> + struct mchp_lvds *lvds = bridge_to_lvds(bridge); >>>> + >>>> + pm_runtime_put(lvds->dev); >>>> + clk_disable(lvds->pclk); >>>> +} >>>> + >>>> +static const struct drm_bridge_funcs mchp_lvds_bridge_funcs = { >>>> + .attach = mchp_lvds_attach, >>>> + .enable = mchp_lvds_enable, >>>> + .disable = mchp_lvds_disable, >>>> +}; >>>> + >>>> +static int mchp_lvds_probe(struct platform_device *pdev) >>>> +{ >>>> + struct device *dev = &pdev->dev; >>>> + struct mchp_lvds *lvds; >>>> + struct device_node *port; >>>> + >>>> + if (!dev->of_node) >>>> + return -ENODEV; >>>> + >>>> + lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL); >>>> + if (!lvds) >>>> + return -ENOMEM; >>>> + >>>> + lvds->dev = dev; >>>> + >>>> + lvds->regs = devm_ioremap_resource(lvds->dev, >>>> + platform_get_resource(pdev, IORESOURCE_MEM, 0)); >>>> + if (IS_ERR(lvds->regs)) >>>> + return PTR_ERR(lvds->regs); >>>> + >>>> + lvds->pclk = devm_clk_get_prepared(lvds->dev, "pclk"); >>> >>> Why do you need _prepared version? >> >> I will change this to just devm_clk_get(). >> >>> >>>> + if (IS_ERR(lvds->pclk)) >>>> + return dev_err_probe(lvds->dev, PTR_ERR(lvds->pclk), >>>> + "could not get pclk_lvds prepared\n"); >>>> + >>>> + port = of_graph_get_remote_node(dev->of_node, 1, 0); >>>> + if (!port) { >>>> + DRM_DEV_ERROR(dev, >>>> + "can't find port point, please init lvds panel port!\n"); >>>> + return -ENODEV; >>>> + } >>>> + >>>> + lvds->panel = of_drm_find_panel(port); >>>> + of_node_put(port); >>>> + >>>> + if (IS_ERR(lvds->panel)) >>>> + return -EPROBE_DEFER; >>>> + >>>> + lvds->panel_bridge = devm_drm_panel_bridge_add(dev, lvds->panel); >>> >>> Please use instead: >>> >>> devm_drm_of_get_bridge(dev, dev->of_node, 1, 0); >> >> Sure, Noted. Thanks. >>> >>>> + >>>> + if (IS_ERR(lvds->panel_bridge)) >>>> + return PTR_ERR(lvds->panel_bridge); >>>> + >>>> + lvds->bridge.of_node = dev->of_node; >>>> + lvds->bridge.type = DRM_MODE_CONNECTOR_LVDS; >>>> + lvds->bridge.funcs = &mchp_lvds_bridge_funcs; >>>> + >>>> + dev_set_drvdata(dev, lvds); >>>> + devm_pm_runtime_enable(dev); >>> >>> Error check is missing. >> >> Sure, I will add this >> >> ret = devm_pm_runtime_enable(dev); >> if (ret < 0) { >> DRM_DEV_ERROR(lvds->dev, "failed to enable pm runtime: > > DRM_DEV_ERROR is deprecated, plese use suitable replacement. Sure, I will replace DRM_DEV_ERROR() with dev_err(). > >> %d\n", ret); >> return ret; >> } >> >> > > -- > With best wishes > Dmitry
diff --git a/drivers/gpu/drm/bridge/Kconfig b/drivers/gpu/drm/bridge/Kconfig index efd996f6c138..889098e2d65f 100644 --- a/drivers/gpu/drm/bridge/Kconfig +++ b/drivers/gpu/drm/bridge/Kconfig @@ -190,6 +190,13 @@ config DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW to DP++. This is used with the i.MX6 imx-ldb driver. You are likely to say N here. +config DRM_MICROCHIP_LVDS_SERIALIZER + tristate "Microchip LVDS serializer support" + depends on OF + depends on DRM_ATMEL_HLCDC + help + Support for Microchip's LVDS serializer. + config DRM_NWL_MIPI_DSI tristate "Northwest Logic MIPI DSI Host controller" depends on DRM diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile index 017b5832733b..7df87b582dca 100644 --- a/drivers/gpu/drm/bridge/Makefile +++ b/drivers/gpu/drm/bridge/Makefile @@ -13,6 +13,7 @@ obj-$(CONFIG_DRM_LONTIUM_LT9611) += lontium-lt9611.o obj-$(CONFIG_DRM_LONTIUM_LT9611UXC) += lontium-lt9611uxc.o obj-$(CONFIG_DRM_LVDS_CODEC) += lvds-codec.o obj-$(CONFIG_DRM_MEGACHIPS_STDPXXXX_GE_B850V3_FW) += megachips-stdpxxxx-ge-b850v3-fw.o +obj-$(CONFIG_DRM_MICROCHIP_LVDS_SERIALIZER) += microchip-lvds.o obj-$(CONFIG_DRM_NXP_PTN3460) += nxp-ptn3460.o obj-$(CONFIG_DRM_PARADE_PS8622) += parade-ps8622.o obj-$(CONFIG_DRM_PARADE_PS8640) += parade-ps8640.o diff --git a/drivers/gpu/drm/bridge/microchip-lvds.c b/drivers/gpu/drm/bridge/microchip-lvds.c new file mode 100644 index 000000000000..149704f498a6 --- /dev/null +++ b/drivers/gpu/drm/bridge/microchip-lvds.c @@ -0,0 +1,228 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2023 Microchip Technology Inc. and its subsidiaries + * + * Author: Manikandan Muralidharan <manikandan.m@microchip.com> + * Author: Dharma Balasubiramani <dharma.b@microchip.com> + * + */ + +#include <linux/clk.h> +#include <linux/component.h> +#include <linux/delay.h> +#include <linux/jiffies.h> +#include <linux/mfd/syscon.h> +#include <linux/of_graph.h> +#include <linux/pinctrl/devinfo.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> +#include <linux/reset.h> + +#include <drm/drm_atomic_helper.h> +#include <drm/drm_bridge.h> +#include <drm/drm_of.h> +#include <drm/drm_panel.h> +#include <drm/drm_print.h> +#include <drm/drm_probe_helper.h> +#include <drm/drm_simple_kms_helper.h> + +#define LVDS_POLL_TIMEOUT_MS 1000 + +/* LVDSC register offsets */ +#define LVDSC_CR 0x00 +#define LVDSC_CFGR 0x04 +#define LVDSC_SR 0x0C +#define LVDSC_WPMR 0xE4 + +/* Bitfields in LVDSC_CR (Control Register) */ +#define LVDSC_CR_SER_EN BIT(0) + +/* Bitfields in LVDSC_CFGR (Configuration Register) */ +#define LVDSC_CFGR_PIXSIZE_24BITS 0 +#define LVDSC_CFGR_DEN_POL_HIGH 0 +#define LVDSC_CFGR_DC_UNBALANCED 0 +#define LVDSC_CFGR_MAPPING_JEIDA BIT(6) + +/*Bitfields in LVDSC_SR */ +#define LVDSC_SR_CS BIT(0) + +/* Bitfields in LVDSC_WPMR (Write Protection Mode Register) */ +#define LVDSC_WPMR_WPKEY_MASK GENMASK(31, 8) +#define LVDSC_WPMR_WPKEY_PSSWD 0x4C5644 + +struct mchp_lvds { + struct device *dev; + void __iomem *regs; + struct clk *pclk; + struct drm_panel *panel; + struct drm_bridge bridge; + struct drm_bridge *panel_bridge; +}; + +static inline struct mchp_lvds *bridge_to_lvds(struct drm_bridge *bridge) +{ + return container_of(bridge, struct mchp_lvds, bridge); +} + +static inline u32 lvds_readl(struct mchp_lvds *lvds, u32 offset) +{ + return readl_relaxed(lvds->regs + offset); +} + +static inline void lvds_writel(struct mchp_lvds *lvds, u32 offset, u32 val) +{ + writel_relaxed(val, lvds->regs + offset); +} + +static void lvds_serialiser_on(struct mchp_lvds *lvds) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(LVDS_POLL_TIMEOUT_MS); + + /* The LVDSC registers can only be written if WPEN is cleared */ + lvds_writel(lvds, LVDSC_WPMR, (LVDSC_WPMR_WPKEY_PSSWD & + LVDSC_WPMR_WPKEY_MASK)); + + /* Wait for the status of configuration registers to be changed */ + while (lvds_readl(lvds, LVDSC_SR) & LVDSC_SR_CS) { + if (time_after(jiffies, timeout)) { + DRM_DEV_ERROR(lvds->dev, "%s: timeout error\n", + __func__); + return; + } + usleep_range(1000, 2000); + } + + /* Configure the LVDSC */ + lvds_writel(lvds, LVDSC_CFGR, (LVDSC_CFGR_MAPPING_JEIDA | + LVDSC_CFGR_DC_UNBALANCED | + LVDSC_CFGR_DEN_POL_HIGH | + LVDSC_CFGR_PIXSIZE_24BITS)); + + /* Enable the LVDS serializer */ + lvds_writel(lvds, LVDSC_CR, LVDSC_CR_SER_EN); +} + +static int mchp_lvds_attach(struct drm_bridge *bridge, + enum drm_bridge_attach_flags flags) +{ + struct mchp_lvds *lvds = bridge_to_lvds(bridge); + + bridge->encoder->encoder_type = DRM_MODE_ENCODER_LVDS; + + return drm_bridge_attach(bridge->encoder, lvds->panel_bridge, + bridge, flags); +} + +static void mchp_lvds_enable(struct drm_bridge *bridge) +{ + struct mchp_lvds *lvds = bridge_to_lvds(bridge); + int ret; + + ret = clk_enable(lvds->pclk); + if (ret < 0) { + DRM_DEV_ERROR(lvds->dev, "failed to enable lvds pclk %d\n", ret); + return; + } + + ret = pm_runtime_get_sync(lvds->dev); + if (ret < 0) { + DRM_DEV_ERROR(lvds->dev, "failed to get pm runtime: %d\n", ret); + clk_disable(lvds->pclk); + return; + } + + lvds_serialiser_on(lvds); +} + +static void mchp_lvds_disable(struct drm_bridge *bridge) +{ + struct mchp_lvds *lvds = bridge_to_lvds(bridge); + + pm_runtime_put(lvds->dev); + clk_disable(lvds->pclk); +} + +static const struct drm_bridge_funcs mchp_lvds_bridge_funcs = { + .attach = mchp_lvds_attach, + .enable = mchp_lvds_enable, + .disable = mchp_lvds_disable, +}; + +static int mchp_lvds_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mchp_lvds *lvds; + struct device_node *port; + + if (!dev->of_node) + return -ENODEV; + + lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL); + if (!lvds) + return -ENOMEM; + + lvds->dev = dev; + + lvds->regs = devm_ioremap_resource(lvds->dev, + platform_get_resource(pdev, IORESOURCE_MEM, 0)); + if (IS_ERR(lvds->regs)) + return PTR_ERR(lvds->regs); + + lvds->pclk = devm_clk_get_prepared(lvds->dev, "pclk"); + if (IS_ERR(lvds->pclk)) + return dev_err_probe(lvds->dev, PTR_ERR(lvds->pclk), + "could not get pclk_lvds prepared\n"); + + port = of_graph_get_remote_node(dev->of_node, 1, 0); + if (!port) { + DRM_DEV_ERROR(dev, + "can't find port point, please init lvds panel port!\n"); + return -ENODEV; + } + + lvds->panel = of_drm_find_panel(port); + of_node_put(port); + + if (IS_ERR(lvds->panel)) + return -EPROBE_DEFER; + + lvds->panel_bridge = devm_drm_panel_bridge_add(dev, lvds->panel); + + if (IS_ERR(lvds->panel_bridge)) + return PTR_ERR(lvds->panel_bridge); + + lvds->bridge.of_node = dev->of_node; + lvds->bridge.type = DRM_MODE_CONNECTOR_LVDS; + lvds->bridge.funcs = &mchp_lvds_bridge_funcs; + + dev_set_drvdata(dev, lvds); + devm_pm_runtime_enable(dev); + + drm_bridge_add(&lvds->bridge); + + return 0; +} + +static const struct of_device_id mchp_lvds_dt_ids[] = { + { + .compatible = "microchip,sam9x75-lvds", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, mchp_lvds_dt_ids); + +static struct platform_driver mchp_lvds_driver = { + .probe = mchp_lvds_probe, + .driver = { + .name = "microchip-lvds", + .of_match_table = mchp_lvds_dt_ids, + }, +}; +module_platform_driver(mchp_lvds_driver); + +MODULE_AUTHOR("Manikandan Muralidharan <manikandan.m@microchip.com>"); +MODULE_AUTHOR("Dharma Balasubiramani <dharma.b@microchip.com>"); +MODULE_DESCRIPTION("Low Voltage Differential Signaling Controller Driver"); +MODULE_LICENSE("GPL");