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#include <linux/amba/bus.h>
#include <linux/amba/clcd.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_graph.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "amba-clcd-nomadik.h"
static struct gpio_desc *grestb;
static struct gpio_desc *scen;
static struct gpio_desc *scl;
static struct gpio_desc *sda;
static u8 tpg110_readwrite_reg(bool write, u8 address, u8 outval)
{
int i;
u8 inval = 0;
/* Assert SCEN */
gpiod_set_value_cansleep(scen, 1);
ndelay(150);
/* Hammer out the address */
for (i = 5; i >= 0; i--) {
if (address & BIT(i))
gpiod_set_value_cansleep(sda, 1);
else
gpiod_set_value_cansleep(sda, 0);
ndelay(150);
/* Send an SCL pulse */
gpiod_set_value_cansleep(scl, 1);
ndelay(160);
gpiod_set_value_cansleep(scl, 0);
ndelay(160);
}
if (write) {
/* WRITE */
gpiod_set_value_cansleep(sda, 0);
} else {
/* READ */
gpiod_set_value_cansleep(sda, 1);
}
ndelay(150);
/* Send an SCL pulse */
gpiod_set_value_cansleep(scl, 1);
ndelay(160);
gpiod_set_value_cansleep(scl, 0);
ndelay(160);
if (!write)
/* HiZ turn-around cycle */
gpiod_direction_input(sda);
ndelay(150);
/* Send an SCL pulse */
gpiod_set_value_cansleep(scl, 1);
ndelay(160);
gpiod_set_value_cansleep(scl, 0);
ndelay(160);
/* Hammer in/out the data */
for (i = 7; i >= 0; i--) {
int value;
if (write) {
value = !!(outval & BIT(i));
gpiod_set_value_cansleep(sda, value);
} else {
value = gpiod_get_value(sda);
if (value)
inval |= BIT(i);
}
ndelay(150);
/* Send an SCL pulse */
gpiod_set_value_cansleep(scl, 1);
ndelay(160);
gpiod_set_value_cansleep(scl, 0);
ndelay(160);
}
gpiod_direction_output(sda, 0);
/* Deassert SCEN */
gpiod_set_value_cansleep(scen, 0);
/* Satisfies SCEN pulse width */
udelay(1);
return inval;
}
static u8 tpg110_read_reg(u8 address)
{
return tpg110_readwrite_reg(false, address, 0);
}
static void tpg110_write_reg(u8 address, u8 outval)
{
tpg110_readwrite_reg(true, address, outval);
}
static void tpg110_startup(struct device *dev)
{
u8 val;
dev_info(dev, "TPG110 display enable\n");
/* De-assert the reset signal */
gpiod_set_value_cansleep(grestb, 0);
mdelay(1);
dev_info(dev, "de-asserted GRESTB\n");
/* Test display communication */
tpg110_write_reg(0x00, 0x55);
val = tpg110_read_reg(0x00);
if (val == 0x55)
dev_info(dev, "passed communication test\n");
val = tpg110_read_reg(0x01);
dev_info(dev, "TPG110 chip ID: %d version: %d\n",
val>>4, val&0x0f);
/* Show display resolution */
val = tpg110_read_reg(0x02);
val &= 7;
switch (val) {
case 0x0:
dev_info(dev, "IN 400x240 RGB -> OUT 800x480 RGB (dual scan)");
break;
case 0x1:
dev_info(dev, "IN 480x272 RGB -> OUT 800x480 RGB (dual scan)");
break;
case 0x4:
dev_info(dev, "480x640 RGB");
break;
case 0x5:
dev_info(dev, "480x272 RGB");
break;
case 0x6:
dev_info(dev, "640x480 RGB");
break;
case 0x7:
dev_info(dev, "800x480 RGB");
break;
default:
dev_info(dev, "ILLEGAL RESOLUTION");
break;
}
val = tpg110_read_reg(0x03);
dev_info(dev, "resolution is controlled by %s\n",
(val & BIT(7)) ? "software" : "hardware");
}
static void tpg110_enable(struct clcd_fb *fb)
{
struct device *dev = &fb->dev->dev;
static bool startup;
u8 val;
if (!startup) {
tpg110_startup(dev);
startup = true;
}
/* Take chip out of standby */
val = tpg110_read_reg(0x03);
val |= BIT(0);
tpg110_write_reg(0x03, val);
}
static void tpg110_disable(struct clcd_fb *fb)
{
u8 val;
dev_info(&fb->dev->dev, "TPG110 display disable\n");
val = tpg110_read_reg(0x03);
/* Put into standby */
val &= ~BIT(0);
tpg110_write_reg(0x03, val);
}
static void tpg110_init(struct device *dev, struct device_node *np,
struct clcd_board *board)
{
dev_info(dev, "TPG110 display init\n");
/* This asserts the GRESTB signal, putting the display into reset */
grestb = devm_get_gpiod_from_child(dev, "grestb", &np->fwnode,
GPIOD_OUT_HIGH, "grestb");
if (IS_ERR(grestb)) {
dev_err(dev, "no GRESTB GPIO\n");
return;
}
scen = devm_get_gpiod_from_child(dev, "scen", &np->fwnode,
GPIOD_OUT_LOW, "scen");
if (IS_ERR(scen)) {
dev_err(dev, "no SCEN GPIO\n");
return;
}
scl = devm_get_gpiod_from_child(dev, "scl", &np->fwnode, GPIOD_OUT_LOW,
"scl");
if (IS_ERR(scl)) {
dev_err(dev, "no SCL GPIO\n");
return;
}
sda = devm_get_gpiod_from_child(dev, "sda", &np->fwnode, GPIOD_OUT_LOW,
"sda");
if (IS_ERR(sda)) {
dev_err(dev, "no SDA GPIO\n");
return;
}
board->enable = tpg110_enable;
board->disable = tpg110_disable;
}
int nomadik_clcd_init_panel(struct clcd_fb *fb,
struct device_node *endpoint)
{
struct device_node *panel;
panel = of_graph_get_remote_port_parent(endpoint);
if (!panel)
return -ENODEV;
if (of_device_is_compatible(panel, "tpo,tpg110"))
tpg110_init(&fb->dev->dev, panel, fb->board);
else
dev_info(&fb->dev->dev, "unknown panel\n");
/* Unknown panel, fall through */
return 0;
}
EXPORT_SYMBOL_GPL(nomadik_clcd_init_panel);
#define PMU_CTRL_OFFSET 0x0000
#define PMU_CTRL_LCDNDIF BIT(26)
int nomadik_clcd_init_board(struct amba_device *adev,
struct clcd_board *board)
{
struct regmap *pmu_regmap;
dev_info(&adev->dev, "Nomadik CLCD board init\n");
pmu_regmap =
syscon_regmap_lookup_by_compatible("stericsson,nomadik-pmu");
if (IS_ERR(pmu_regmap)) {
dev_err(&adev->dev, "could not find PMU syscon regmap\n");
return PTR_ERR(pmu_regmap);
}
regmap_update_bits(pmu_regmap,
PMU_CTRL_OFFSET,
PMU_CTRL_LCDNDIF,
0);
dev_info(&adev->dev, "set PMU mux to CLCD mode\n");
return 0;
}
EXPORT_SYMBOL_GPL(nomadik_clcd_init_board);
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