| 1 | /* |
| 2 | * Copyright (C) 2009, Lars-Peter Clausen <lars@metafoo.de> |
| 3 | * JZ4720/JZ4740 SoC LCD framebuffer driver |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License as published by the |
| 7 | * Free Software Foundation; either version 2 of the License, or (at your |
| 8 | * option) any later version. |
| 9 | * |
| 10 | * You should have received a copy of the GNU General Public License along |
| 11 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 12 | * 675 Mass Ave, Cambridge, MA 02139, USA. |
| 13 | * |
| 14 | */ |
| 15 | |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/spi/spi.h> |
| 18 | #include <linux/lcd.h> |
| 19 | #include <linux/backlight.h> |
| 20 | #include <linux/delay.h> |
| 21 | |
| 22 | struct gpm940b0 { |
| 23 | struct spi_device *spi; |
| 24 | struct lcd_device *lcd; |
| 25 | struct backlight_device *bl; |
| 26 | unsigned enabled:1; |
| 27 | }; |
| 28 | |
| 29 | static int gpm940b0_write_reg(struct spi_device *spi, uint8_t reg, |
| 30 | uint8_t data) |
| 31 | { |
| 32 | uint8_t buf[2]; |
| 33 | buf[0] = ((reg & 0x40) << 1) | (reg & 0x3f); |
| 34 | buf[1] = data; |
| 35 | |
| 36 | return spi_write(spi, buf, sizeof(buf)); |
| 37 | } |
| 38 | |
| 39 | static void gpm940b0_power_disable(struct gpm940b0 *gpm940b0) |
| 40 | { |
| 41 | int ret = gpm940b0_write_reg(gpm940b0->spi, 0x5, 0xc6) ; |
| 42 | if (ret < 0) |
| 43 | printk("Failed to disable power: %d\n", ret); |
| 44 | } |
| 45 | |
| 46 | static void gpm940b0_power_enable(struct gpm940b0 *gpm940b0) |
| 47 | { |
| 48 | gpm940b0_write_reg(gpm940b0->spi, 0x5, 0xc7); |
| 49 | } |
| 50 | |
| 51 | |
| 52 | static int gpm940b0_set_power(struct lcd_device *lcd, int power) |
| 53 | { |
| 54 | struct gpm940b0 *gpm940b0 = lcd_get_data(lcd); |
| 55 | |
| 56 | switch (power) { |
| 57 | case FB_BLANK_UNBLANK: |
| 58 | mdelay(20); |
| 59 | gpm940b0->enabled = 1; |
| 60 | gpm940b0_power_enable(gpm940b0); |
| 61 | break; |
| 62 | default: |
| 63 | gpm940b0->enabled = 0; |
| 64 | gpm940b0_power_disable(gpm940b0); |
| 65 | mdelay(20); |
| 66 | break; |
| 67 | } |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | static int gpm940b0_set_contrast(struct lcd_device *lcd, int contrast) |
| 72 | { |
| 73 | struct gpm940b0 *gpm940b0 = lcd_get_data(lcd); |
| 74 | gpm940b0_write_reg(gpm940b0->spi, 0x0d, contrast); |
| 75 | return 0; |
| 76 | } |
| 77 | |
| 78 | static int gpm940b0_set_mode(struct lcd_device *lcd, struct fb_videomode *mode) |
| 79 | { |
| 80 | if (mode->xres != 320 && mode->yres != 240) |
| 81 | return -EINVAL; |
| 82 | |
| 83 | return 0; |
| 84 | } |
| 85 | |
| 86 | int gpm940b0_bl_get_brightness(struct backlight_device *bl) |
| 87 | { |
| 88 | return bl->props.brightness; |
| 89 | } |
| 90 | |
| 91 | int gpm940b0_bl_update_status(struct backlight_device *bl) |
| 92 | { |
| 93 | struct gpm940b0 *gpm940b0 = bl_get_data(bl); |
| 94 | |
| 95 | gpm940b0_write_reg(gpm940b0->spi, 0x3, (bl->props.brightness)); |
| 96 | |
| 97 | return 0; |
| 98 | } |
| 99 | |
| 100 | static ssize_t reg_write(struct device *dev, struct device_attribute *attr, |
| 101 | const char *buf, size_t count) |
| 102 | { |
| 103 | char *buf2; |
| 104 | uint32_t reg = simple_strtoul(buf, &buf2, 10); |
| 105 | uint32_t val = simple_strtoul(buf2 + 1, NULL, 10); |
| 106 | struct gpm940b0 *gpm940b0 = dev_get_drvdata(dev); |
| 107 | |
| 108 | if (reg < 0 || val < 0) |
| 109 | return -EINVAL; |
| 110 | |
| 111 | gpm940b0_write_reg(gpm940b0->spi, reg, val); |
| 112 | return count; |
| 113 | } |
| 114 | |
| 115 | static DEVICE_ATTR(reg, 0644, NULL, reg_write); |
| 116 | |
| 117 | static struct lcd_ops gpm940b0_lcd_ops = { |
| 118 | .set_power = gpm940b0_set_power, |
| 119 | .set_contrast = gpm940b0_set_contrast, |
| 120 | .set_mode = gpm940b0_set_mode, |
| 121 | }; |
| 122 | |
| 123 | static struct backlight_ops gpm940b0_bl_ops = { |
| 124 | .get_brightness = gpm940b0_bl_get_brightness, |
| 125 | .update_status = gpm940b0_bl_update_status, |
| 126 | }; |
| 127 | |
| 128 | static int __devinit gpm940b0_probe(struct spi_device *spi) |
| 129 | { |
| 130 | int ret; |
| 131 | struct gpm940b0 *gpm940b0; |
| 132 | |
| 133 | gpm940b0 = kmalloc(sizeof(*gpm940b0), GFP_KERNEL); |
| 134 | |
| 135 | spi->bits_per_word = 8; |
| 136 | |
| 137 | ret = spi_setup(spi); |
| 138 | if (ret) { |
| 139 | dev_err(&spi->dev, "Failed to setup spi\n"); |
| 140 | goto err_free_gpm940b0; |
| 141 | } |
| 142 | |
| 143 | gpm940b0->spi = spi; |
| 144 | |
| 145 | gpm940b0->lcd = lcd_device_register("gpm940b0-lcd", &spi->dev, gpm940b0, |
| 146 | &gpm940b0_lcd_ops); |
| 147 | |
| 148 | if (IS_ERR(gpm940b0->lcd)) { |
| 149 | ret = PTR_ERR(gpm940b0->lcd); |
| 150 | dev_err(&spi->dev, "Failed to register lcd device: %d\n", ret); |
| 151 | goto err_free_gpm940b0; |
| 152 | } |
| 153 | |
| 154 | gpm940b0->lcd->props.max_contrast = 255; |
| 155 | |
| 156 | gpm940b0->bl = backlight_device_register("gpm940b0-bl", &spi->dev, gpm940b0, |
| 157 | &gpm940b0_bl_ops); |
| 158 | |
| 159 | if (IS_ERR(gpm940b0->bl)) { |
| 160 | ret = PTR_ERR(gpm940b0->bl); |
| 161 | dev_err(&spi->dev, "Failed to register backlight device: %d\n", ret); |
| 162 | gpm940b0->bl = NULL; |
| 163 | } else { |
| 164 | gpm940b0->bl->props.max_brightness = 255; |
| 165 | gpm940b0->bl->props.brightness = 64; |
| 166 | gpm940b0->bl->props.power = FB_BLANK_UNBLANK; |
| 167 | } |
| 168 | backlight_update_status(gpm940b0->bl); |
| 169 | |
| 170 | ret = device_create_file(&spi->dev, &dev_attr_reg); |
| 171 | if (ret) |
| 172 | goto err_unregister_lcd; |
| 173 | |
| 174 | gpm940b0->enabled = 1; |
| 175 | dev_set_drvdata(&spi->dev, gpm940b0); |
| 176 | |
| 177 | gpm940b0_write_reg(spi, 0x07, 0x8d); |
| 178 | gpm940b0_write_reg(spi, 0x13, 0x01); |
| 179 | gpm940b0_write_reg(spi, 0x5, 0xc7); |
| 180 | return 0; |
| 181 | err_unregister_lcd: |
| 182 | lcd_device_unregister(gpm940b0->lcd); |
| 183 | err_free_gpm940b0: |
| 184 | kfree(gpm940b0); |
| 185 | return ret; |
| 186 | } |
| 187 | |
| 188 | static int __devexit gpm940b0_remove(struct spi_device *spi) |
| 189 | { |
| 190 | struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi); |
| 191 | if (gpm940b0->bl) |
| 192 | backlight_device_unregister(gpm940b0->bl); |
| 193 | |
| 194 | lcd_device_unregister(gpm940b0->lcd); |
| 195 | |
| 196 | spi_set_drvdata(spi, NULL); |
| 197 | kfree(gpm940b0); |
| 198 | return 0; |
| 199 | } |
| 200 | |
| 201 | #ifdef CONFIG_PM |
| 202 | |
| 203 | static int gpm940b0_suspend(struct spi_device *spi, pm_message_t state) |
| 204 | { |
| 205 | struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi); |
| 206 | if (gpm940b0->enabled) { |
| 207 | gpm940b0_power_disable(gpm940b0); |
| 208 | mdelay(10); |
| 209 | } |
| 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | static int gpm940b0_resume(struct spi_device *spi) |
| 214 | { |
| 215 | struct gpm940b0 *gpm940b0 = spi_get_drvdata(spi); |
| 216 | if (gpm940b0->enabled) |
| 217 | gpm940b0_power_enable(gpm940b0); |
| 218 | return 0; |
| 219 | } |
| 220 | |
| 221 | #else |
| 222 | #define gpm940b0_suspend NULL |
| 223 | #define gpm940b0_resume NULL |
| 224 | #endif |
| 225 | |
| 226 | static struct spi_driver gpm940b0_driver = { |
| 227 | .driver = { |
| 228 | .name = "gpm940b0", |
| 229 | .owner = THIS_MODULE, |
| 230 | }, |
| 231 | .probe = gpm940b0_probe, |
| 232 | .remove = __devexit_p(gpm940b0_remove), |
| 233 | .suspend = gpm940b0_suspend, |
| 234 | .resume = gpm940b0_resume, |
| 235 | }; |
| 236 | |
| 237 | static int __init gpm940b0_init(void) |
| 238 | { |
| 239 | return spi_register_driver(&gpm940b0_driver); |
| 240 | } |
| 241 | module_init(gpm940b0_init); |
| 242 | |
| 243 | static void __exit gpm940b0_exit(void) |
| 244 | { |
| 245 | return spi_unregister_driver(&gpm940b0_driver); |
| 246 | } |
| 247 | module_exit(gpm940b0_exit) |
| 248 | |
| 249 | MODULE_AUTHOR("Lars-Peter Clausen"); |
| 250 | MODULE_LICENSE("GPL v2"); |
| 251 | MODULE_DESCRIPTION("LCD and backlight controll for Giantplus GPM940B0"); |
| 252 | MODULE_ALIAS("spi:gpm940b0"); |
| 253 | |
