diff options
Diffstat (limited to 'drivers/video/fbdev/amba-clcd-nomadik.c')
| -rw-r--r-- | drivers/video/fbdev/amba-clcd-nomadik.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/drivers/video/fbdev/amba-clcd-nomadik.c b/drivers/video/fbdev/amba-clcd-nomadik.c new file mode 100644 index 000000000..cd2db1113 --- /dev/null +++ b/drivers/video/fbdev/amba-clcd-nomadik.c @@ -0,0 +1,251 @@ +#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_fwnode_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_fwnode_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_fwnode_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_fwnode_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 *panel) +{ + 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); |