diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/gpu/drm/bridge/microchip-lvds.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/microchip-lvds.c b/drivers/gpu/drm/bridge/microchip-lvds.c new file mode 100644 index 0000000000..b8313dad60 --- /dev/null +++ b/drivers/gpu/drm/bridge/microchip-lvds.c @@ -0,0 +1,229 @@ +// 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)) { + dev_err(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); + + 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_prepare_enable(lvds->pclk); + if (ret < 0) { + dev_err(lvds->dev, "failed to enable lvds pclk %d\n", ret); + return; + } + + ret = pm_runtime_get_sync(lvds->dev); + if (ret < 0) { + dev_err(lvds->dev, "failed to get pm runtime: %d\n", ret); + 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_unprepare(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; + int ret; + + 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(lvds->dev, "pclk"); + if (IS_ERR(lvds->pclk)) + return dev_err_probe(lvds->dev, PTR_ERR(lvds->pclk), + "could not get pclk_lvds\n"); + + port = of_graph_get_remote_node(dev->of_node, 1, 0); + if (!port) { + dev_err(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_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); + ret = devm_pm_runtime_enable(dev); + if (ret < 0) { + dev_err(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"); |