1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/device.h> 4 #include <linux/module.h> 5 #include <linux/spi/spi.h> 6 #include <linux/delay.h> 7 8 #include <drm/drm_print.h> 9 10 #include "panel-samsung-s6e63m0.h" 11 12 #define DATA_MASK 0x100 13 14 static int s6e63m0_spi_dcs_read(struct device *dev, const u8 cmd, u8 *data) 15 { 16 /* 17 * FIXME: implement reading DCS commands over SPI so we can 18 * properly identify which physical panel is connected. 19 */ 20 *data = 0; 21 22 return 0; 23 } 24 25 static int s6e63m0_spi_write_word(struct device *dev, u16 data) 26 { 27 struct spi_device *spi = to_spi_device(dev); 28 struct spi_transfer xfer = { 29 .len = 2, 30 .tx_buf = &data, 31 }; 32 struct spi_message msg; 33 34 spi_message_init(&msg); 35 spi_message_add_tail(&xfer, &msg); 36 37 return spi_sync(spi, &msg); 38 } 39 40 static int s6e63m0_spi_dcs_write(struct device *dev, const u8 *data, size_t len) 41 { 42 int ret = 0; 43 44 dev_dbg(dev, "SPI writing dcs seq: %*ph\n", (int)len, data); 45 ret = s6e63m0_spi_write_word(dev, *data); 46 47 while (!ret && --len) { 48 ++data; 49 ret = s6e63m0_spi_write_word(dev, *data | DATA_MASK); 50 } 51 52 if (ret) { 53 dev_err(dev, "SPI error %d writing dcs seq: %*ph\n", ret, 54 (int)len, data); 55 } 56 57 usleep_range(300, 310); 58 59 return ret; 60 } 61 62 static int s6e63m0_spi_probe(struct spi_device *spi) 63 { 64 struct device *dev = &spi->dev; 65 int ret; 66 67 spi->bits_per_word = 9; 68 spi->mode = SPI_MODE_3; 69 ret = spi_setup(spi); 70 if (ret < 0) { 71 dev_err(dev, "spi setup failed.\n"); 72 return ret; 73 } 74 return s6e63m0_probe(dev, s6e63m0_spi_dcs_read, s6e63m0_spi_dcs_write, 75 false); 76 } 77 78 static int s6e63m0_spi_remove(struct spi_device *spi) 79 { 80 return s6e63m0_remove(&spi->dev); 81 } 82 83 static const struct of_device_id s6e63m0_spi_of_match[] = { 84 { .compatible = "samsung,s6e63m0" }, 85 { /* sentinel */ } 86 }; 87 MODULE_DEVICE_TABLE(of, s6e63m0_spi_of_match); 88 89 static struct spi_driver s6e63m0_spi_driver = { 90 .probe = s6e63m0_spi_probe, 91 .remove = s6e63m0_spi_remove, 92 .driver = { 93 .name = "panel-samsung-s6e63m0", 94 .of_match_table = s6e63m0_spi_of_match, 95 }, 96 }; 97 module_spi_driver(s6e63m0_spi_driver); 98 99 MODULE_AUTHOR("Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>"); 100 MODULE_DESCRIPTION("s6e63m0 LCD SPI Driver"); 101 MODULE_LICENSE("GPL v2"); 102