target/linux/s3c24xx/files-2.6.30/drivers/mfd/glamo/glamo-lcm-spi.c

   1 /*
   2  * Copyright (C) 2007 Openmoko, Inc.
   3  * Author: Harald Welte <laforge@openmoko.org>
   4  *
   5  * Smedia Glamo GPIO based SPI driver
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This driver currently only implements a minimum subset of the hardware
  12  * features, esp. those features that are required to drive the jbt6k74
  13  * LCM controller asic in the TD028TTEC1 LCM.
  14  *
  15 */
  16
  17 #define DEBUG
  18
  19 #include <linux/kernel.h>
  20 #include <linux/init.h>
  21 #include <linux/delay.h>
  22 #include <linux/device.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/workqueue.h>
  25 #include <linux/platform_device.h>
  26
  27 #include <linux/spi/spi.h>
  28 #include <linux/spi/spi_bitbang.h>
  29 #include <linux/spi/glamo.h>
  30
  31 #include <linux/glamofb.h>
  32
  33 #include <mach/hardware.h>
  34
  35 #include "glamo-core.h"
  36 #include "glamo-regs.h"
  37
  38 struct glamo_spi {
  39         struct spi_bitbang      bitbang;
  40         struct spi_master       *master;
  41         struct glamo_spi_info   *info;
  42         struct device           *dev;
  43 };
  44
  45 static inline struct glamo_spi *to_gs(struct spi_device *spi)
  46 {
  47         return spi->controller_data;
  48 }
  49
  50 static int glamo_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t)
  51 {
  52         unsigned int bpw;
  53
  54         bpw = t ? t->bits_per_word : spi->bits_per_word;
  55
  56         if (bpw != 9 && bpw != 8) {
  57                 dev_err(&spi->dev, "invalid bits-per-word (%d)\n", bpw);
  58                 return -EINVAL;
  59         }
  60
  61         return 0;
  62 }
  63
  64 static void glamo_spi_chipsel(struct spi_device *spi, int value)
  65 {
  66 #if 0
  67         struct glamo_spi *gs = to_gs(spi);
  68
  69         dev_dbg(&spi->dev, "chipsel %d: spi=%p, gs=%p, info=%p, handle=%p\n",
  70                 value, spi, gs, gs->info, gs->info->glamofb_handle);
  71
  72         glamofb_cmd_mode(gs->info->glamofb_handle, value);
  73 #endif
  74 }
  75
  76 static int glamo_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
  77 {
  78         struct glamo_spi *gs = to_gs(spi);
  79         const u_int16_t *ui16 = (const u_int16_t *) t->tx_buf;
  80         u_int16_t nine_bits;
  81         int i;
  82
  83         dev_dbg(&spi->dev, "txrx: tx %p, rx %p, bpw %d, len %d\n",
  84                 t->tx_buf, t->rx_buf, t->bits_per_word, t->len);
  85
  86         if (spi->bits_per_word == 9)
  87                 nine_bits = (1 << 9);
  88         else
  89                 nine_bits = 0;
  90
  91         if (t->len > 3 * sizeof(u_int16_t)) {
  92                 dev_err(&spi->dev, "this driver doesn't support "
  93                         "%u sized xfers\n", t->len);
  94                 return -EINVAL;
  95         }
  96
  97         for (i = 0; i < t->len/sizeof(u_int16_t); i++) {
  98                 /* actually transfer the data */
  99 #if 1
 100                 glamofb_cmd_write(gs->info->glamofb_handle,
 101                                   GLAMO_LCD_CMD_TYPE_SERIAL | nine_bits |
 102                                   (1 << 10) | (1 << 11) | (ui16[i] & 0x1ff));
 103 #endif
 104                 /* FIXME: fire ?!? */
 105                 if (i == 0 && (ui16[i] & 0x1ff) == 0x29) {
 106                         dev_dbg(&spi->dev, "leaving command mode\n");
 107                         glamofb_cmd_mode(gs->info->glamofb_handle, 0);
 108                 }
 109         }
 110
 111         return t->len;
 112 }
 113
 114 static int glamo_spi_setup(struct spi_device *spi)
 115 {
 116         int ret;
 117
 118         if (!spi->bits_per_word)
 119                 spi->bits_per_word = 9;
 120
 121         /* FIXME: hardware can do this */
 122         if (spi->mode & SPI_LSB_FIRST)
 123                 return -EINVAL;
 124
 125         ret = glamo_spi_setupxfer(spi, NULL);
 126         if (ret < 0) {
 127                 dev_err(&spi->dev, "setupxfer returned %d\n", ret);
 128                 return ret;
 129         }
 130
 131         dev_dbg(&spi->dev, "%s: mode %d, %u bpw\n",
 132                 __FUNCTION__, spi->mode, spi->bits_per_word);
 133
 134         return 0;
 135 }
 136
 137 static int glamo_spi_probe(struct platform_device *pdev)
 138 {
 139         struct spi_master *master;
 140         struct glamo_spi *sp;
 141         int ret;
 142         int i;
 143
 144         master = spi_alloc_master(&pdev->dev, sizeof(struct glamo_spi));
 145         if (master == NULL) {
 146                 dev_err(&pdev->dev, "failed to allocate spi master\n");
 147                 ret = -ENOMEM;
 148                 goto err;
 149         }
 150
 151         sp = spi_master_get_devdata(master);
 152         memset(sp, 0, sizeof(struct glamo_spi));
 153
 154         sp->master = spi_master_get(master);
 155         sp->info = pdev->dev.platform_data;
 156         if (!sp->info) {
 157                 dev_err(&pdev->dev, "can't operate without platform data\n");
 158                 ret = -EIO;
 159                 goto err_no_pdev;
 160         }
 161         dev_dbg(&pdev->dev, "sp->info(pdata) = %p\n", sp->info);
 162
 163         sp->dev = &pdev->dev;
 164
 165         platform_set_drvdata(pdev, sp);
 166
 167         sp->bitbang.master = sp->master;
 168         sp->bitbang.setup_transfer = glamo_spi_setupxfer;
 169         sp->bitbang.chipselect = glamo_spi_chipsel;
 170         sp->bitbang.txrx_bufs = glamo_spi_txrx;
 171         sp->bitbang.master->setup = glamo_spi_setup;
 172
 173         ret = spi_bitbang_start(&sp->bitbang);
 174         if (ret)
 175                 goto err_no_bitbang;
 176
 177         /* register the chips to go with the board */
 178
 179         glamofb_cmd_mode(sp->info->glamofb_handle, 1);
 180
 181         for (i = 0; i < sp->info->board_size; i++) {
 182                 dev_info(&pdev->dev, "registering %p: %s\n",
 183                          &sp->info->board_info[i],
 184                          sp->info->board_info[i].modalias);
 185
 186                 sp->info->board_info[i].controller_data = sp;
 187                 spi_new_device(master, sp->info->board_info + i);
 188         }
 189
 190         return 0;
 191
 192 err_no_bitbang:
 193         platform_set_drvdata(pdev, NULL);
 194 err_no_pdev:
 195         spi_master_put(sp->bitbang.master);
 196 err:
 197         return ret;
 198
 199 }
 200
 201 static int glamo_spi_remove(struct platform_device *pdev)
 202 {
 203         struct glamo_spi *sp = platform_get_drvdata(pdev);
 204
 205         spi_bitbang_stop(&sp->bitbang);
 206         spi_master_put(sp->bitbang.master);
 207
 208         return 0;
 209 }
 210
 211 #define glamo_spi_suspend NULL
 212 #define glamo_spi_resume NULL
 213
 214 static struct platform_driver glamo_spi_drv = {
 215         .probe          = glamo_spi_probe,
 216         .remove         = glamo_spi_remove,
 217         .suspend        = glamo_spi_suspend,
 218         .resume         = glamo_spi_resume,
 219         .driver         = {
 220                 .name   = "glamo-lcm-spi",
 221                 .owner  = THIS_MODULE,
 222         },
 223 };
 224
 225 static int __init glamo_spi_init(void)
 226 {
 227         return platform_driver_register(&glamo_spi_drv);
 228 }
 229
 230 static void __exit glamo_spi_exit(void)
 231 {
 232         platform_driver_unregister(&glamo_spi_drv);
 233 }
 234
 235 module_init(glamo_spi_init);
 236 module_exit(glamo_spi_exit);
 237
 238 MODULE_DESCRIPTION("Smedia Glamo 336x/337x LCM serial command SPI Driver");
 239 MODULE_AUTHOR("Harald Welte <laforge@openmoko.org>")
 240 MODULE_LICENSE("GPL");