// SPDX-License-Identifier: GPL-2.0
/*
* Panel driver for the ARM Versatile family reference designs from
* ARM Limited.
*
* Author:
* Linus Walleij <linus.wallei@linaro.org>
*
* On the Versatile AB, these panels come mounted on daughterboards
* named "IB1" or "IB2" (Interface Board 1 & 2 respectively.) They
* are documented in ARM DUI 0225D Appendix C and D. These daughter
* boards support TFT display panels.
*
* - The IB1 is a passive board where the display connector defines a
* few wires for encoding the display type for autodetection,
* suitable display settings can then be looked up from this setting.
* The magic bits can be read out from the system controller.
*
* - The IB2 is a more complex board intended for GSM phone development
* with some logic and a control register, which needs to be accessed
* and the board display needs to be turned on explicitly.
*
* On the Versatile PB, a special CLCD adaptor board is available
* supporting the same displays as the Versatile AB, plus one more
* Epson QCIF display.
*
*/
#include <linux/bitops.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mfd/syscon.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <video/of_videomode.h>
#include <video/videomode.h>
#include <drm/drm_modes.h>
#include <drm/drm_panel.h>
/*
* This configuration register in the Versatile and RealView
* family is uniformly present but appears more and more
* unutilized starting with the RealView series.
*/
#define SYS_CLCD 0x50
/* The Versatile can detect the connected panel type */
#define SYS_CLCD_CLCDID_MASK (BIT(8)|BIT(9)|BIT(10)|BIT(11)|BIT(12))
#define SYS_CLCD_ID_SANYO_3_8 (0x00 << 8)
#define SYS_CLCD_ID_SHARP_8_4 (0x01 << 8)
#define SYS_CLCD_ID_EPSON_2_2 (0x02 << 8)
#define SYS_CLCD_ID_SANYO_2_5 (0x07 << 8)
#define SYS_CLCD_ID_VGA (0x1f << 8)
/* IB2 control register for the Versatile daughterboard */
#define IB2_CTRL 0x00
#define IB2_CTRL_LCD_SD BIT(1) /* 1 = shut down LCD */
#define IB2_CTRL_LCD_BL_ON BIT(0)
#define IB2_CTRL_LCD_MASK (BIT(0)|BIT(1))
/**
* struct versatile_panel_type - lookup struct for the supported panels
*/
struct versatile_panel_type {
/**
* @name: the name of this panel
*/
const char *name;
/**
* @magic: the magic value from the detection register
*/
u32 magic;
/**
* @mode: the DRM display mode for this panel
*/
struct drm_display_mode mode;
/**
* @bus_flags: the DRM bus flags for this panel e.g. inverted clock
*/
u32 bus_flags;
/**
* @width_mm: the panel width in mm
*/
u32 width_mm;
/**
* @height_mm: the panel height in mm
*/
u32 height_mm;
/**
* @ib2: the panel may be connected on an IB2 daughterboard
*/
bool ib2;
};
/**
* struct versatile_panel - state container for the Versatile panels
*/
struct versatile_panel {
/**
* @dev: the container device
*/
struct device *dev;
/**
* @panel: the DRM panel instance for this device
*/
struct drm_panel panel;
/**
* @panel_type: the Versatile panel type as detected
*/
const struct versatile_panel_type *panel_type;
/**
* @map: map to the parent syscon where the main register reside
*/
struct regmap *map;
/**
* @ib2_map: map to the IB2 syscon, if applicable
*/
struct regmap *ib2_map;
};
static const struct versatile_panel_type versatile_panels[] = {
/*
* Sanyo TM38QV67A02A - 3.8 inch QVGA (320x240) Color TFT
* found on the Versatile AB IB1 connector or the Versatile
* PB adaptor board connector.
*/
{
.name = "Sanyo TM38QV67A02A",
.magic = SYS_CLCD_ID_SANYO_3_8,
.width_mm = 79,
.height_mm = 54,
.mode = {
.clock = 10000,
.hdisplay = 320,
.hsync_start = 320 + 6,
.hsync_end = 320 + 6 + 6,
.htotal = 320 + 6 + 6 + 6,
.vdisplay = 240,
.vsync_start = 240 + 5,
.vsync_end = 240 + 5 + 6,
.vtotal = 240 + 5 + 6 + 5,
.vrefresh = 116,
.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
},
},
/*
* Sharp LQ084V1DG21 640x480 VGA Color TFT module
* found on the Versatile AB IB1 connector or the Versatile
* PB adaptor board connector.
*/
{
.name = "Sharp LQ084V1DG21",
.magic = SYS_CLCD_ID_SHARP_8_4,
.width_mm = 171,
.height_mm = 130,
.mode = {
.clock = 25000,
.hdisplay = 640,
.hsync_start = 640 + 24,
.hsync_end = 640 + 24 + 96,
.htotal = 640 + 24 + 96 + 24,
.vdisplay = 480,
.vsync_start = 480 + 11,
.vsync_end = 480 + 11 + 2,
.vtotal = 480 + 11 + 2 + 32,
.vrefresh = 60,
.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
},
},
/*
* Epson L2F50113T00 - 2.2 inch QCIF 176x220 Color TFT
* found on the Versatile PB adaptor board connector.
*/
{
.name = "Epson L2F50113T00",
.magic = SYS_CLCD_ID_EPSON_2_2,
.width_mm = 34,
.height_mm = 45,
.mode = {
.clock = 62500,
.hdisplay = 176,
.hsync_start = 176 + 2,
.hsync_end = 176 + 2 + 3,
.htotal = 176 + 2 + 3 + 3,
.vdisplay = 220,
.vsync_start = 220 + 0,
.vsync_end = 220 + 0 + 2,
.vtotal = 220 + 0 + 2 + 1,
.vrefresh = 390,
.flags = DRM_MODE_FLAG_PHSYNC | DRM_MODE_FLAG_PVSYNC,
},
.bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
},
/*
* Sanyo ALR252RGT 240x320 portrait display found on the
* Versatile AB IB2 daughterboard for GSM prototyping.
*/
{
.name = "Sanyo ALR252RGT",
.magic = SYS_CLCD_ID_SANYO_2_5,
.width_mm = 37,
.height_mm = 50,
.mode = {
.clock = 5400,
.hdisplay = 240,
.hsync_start = 240 + 10,
.hsync_end = 240 + 10 + 10,
.htotal = 240 + 10 + 10 + 20,
.vdisplay = 320,
.vsync_start = 320 + 2,
.vsync_end = 320 + 2 + 2,
.vtotal = 320 + 2 + 2 + 2,
.vrefresh = 116,
.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
},
.bus_flags = DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE,
.ib2 = true,
},
};
static inline struct versatile_panel *
to_versatile_panel(struct drm_panel *panel)
{
return container_of(panel, struct versatile_panel, panel);
}
static int versatile_panel_disable(struct drm_panel *panel)
{
struct versatile_panel *vpanel = to_versatile_panel(panel);
/* If we're on an IB2 daughterboard, turn off display */
if (vpanel->ib2_map) {
dev_dbg(vpanel->dev, "disable IB2 display\n");
regmap_update_bits(vpanel->ib2_map,
IB2_CTRL,
IB2_CTRL_LCD_MASK,
IB2_CTRL_LCD_SD);
}
return 0;
}
static int versatile_panel_enable(struct drm_panel *panel)
{
struct versatile_panel *vpanel = to_versatile_panel(panel);
/* If we're on an IB2 daughterboard, turn on display */
if (vpanel->ib2_map) {
dev_dbg(vpanel->dev, "enable IB2 display\n");
regmap_update_bits(vpanel->ib2_map,
IB2_CTRL,
IB2_CTRL_LCD_MASK,
IB2_CTRL_LCD_BL_ON);
}
return 0;
}
static int versatile_panel_get_modes(struct drm_panel *panel)
{
struct drm_connector *connector = panel->connector;
struct versatile_panel *vpanel = to_versatile_panel(panel);
struct drm_display_mode *mode;
connector->display_info.width_mm = vpanel->panel_type->width_mm;
connector->display_info.height_mm = vpanel->panel_type->height_mm;
connector->display_info.bus_flags = vpanel->panel_type->bus_flags;
mode = drm_mode_duplicate(panel->drm, &vpanel->panel_type->mode);
drm_mode_set_name(mode);
mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
mode->width_mm = vpanel->panel_type->width_mm;
mode->height_mm = vpanel->panel_type->height_mm;
drm_mode_probed_add(connector, mode);
return 1;
}
static const struct drm_panel_funcs versatile_panel_drm_funcs = {
.disable = versatile_panel_disable,
.enable = versatile_panel_enable,
.get_modes = versatile_panel_get_modes,
};
static int versatile_panel_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct versatile_panel *vpanel;
struct device *parent;
struct regmap *map;
int ret;
u32 val;
int i;
parent = dev->parent;
if (!parent) {
dev_err(dev, "no parent for versatile panel\n");
return -ENODEV;
}
map = syscon_node_to_regmap(parent->of_node);
if (IS_ERR(map)) {
dev_err(dev, "no regmap for versatile panel parent\n");
return PTR_ERR(map);
}
vpanel = devm_kzalloc(dev, sizeof(*vpanel), GFP_KERNEL);
if (!vpanel)
return -ENOMEM;
ret = regmap_read(map, SYS_CLCD, &val);
if (ret) {
dev_err(dev, "cannot access syscon regs\n");
return ret;
}
val &= SYS_CLCD_CLCDID_MASK;
for (i = 0; i < ARRAY_SIZE(versatile_panels); i++) {
const struct versatile_panel_type *pt;
pt = &versatile_panels[i];
if (pt->magic == val) {
vpanel->panel_type = pt;
break;
}
}
/* No panel detected or VGA, let's leave this show */
if (i == ARRAY_SIZE(versatile_panels)) {
dev_info(dev, "no panel detected\n");
return -ENODEV;
}
dev_info(dev, "detected: %s\n", vpanel->panel_type->name);
vpanel->dev = dev;
vpanel->map = map;
/* Check if the panel is mounted on an IB2 daughterboard */
if (vpanel->panel_type->ib2) {
vpanel->ib2_map = syscon_regmap_lookup_by_compatible(
"arm,versatile-ib2-syscon");
if (IS_ERR(vpanel->ib2_map))
vpanel->ib2_map = NULL;
else
dev_info(dev, "panel mounted on IB2 daughterboard\n");
}
drm_panel_init(&vpanel->panel);
vpanel->panel.dev = dev;
vpanel->panel.funcs = &versatile_panel_drm_funcs;
return drm_panel_add(&vpanel->panel);
}
static const struct of_device_id versatile_panel_match[] = {
{ .compatible = "arm,versatile-tft-panel", },
{},
};
MODULE_DEVICE_TABLE(of, versatile_panel_match);
static struct platform_driver versatile_panel_driver = {
.probe = versatile_panel_probe,
.driver = {
.name = "versatile-tft-panel",
.of_match_table = versatile_panel_match,
},
};
module_platform_driver(versatile_panel_driver);
MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("ARM Versatile panel driver");
MODULE_LICENSE("GPL v2");