// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2023 Microchip Technology Inc. and its subsidiaries
*
* Author: Manikandan Muralidharan <[email protected]>
* Author: Dharma Balasubiramani <[email protected]>
*
*/
#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 <[email protected]>");
MODULE_AUTHOR("Dharma Balasubiramani <[email protected]>");
MODULE_DESCRIPTION("Low Voltage Differential Signaling Controller Driver");
MODULE_LICENSE("GPL");
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