drivers/mmc/host/renesas_sdhi_internal_dmac.c

   1 /*
   2  * DMA support for Internal DMAC with SDHI SD/SDIO controller
   3  *
   4  * Copyright (C) 2016-17 Renesas Electronics Corporation
   5  * Copyright (C) 2016-17 Horms Solutions, Simon Horman
   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
  12 #include <linux/bitops.h>
  13 #include <linux/device.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/io-64-nonatomic-hi-lo.h>
  16 #include <linux/mfd/tmio.h>
  17 #include <linux/mmc/host.h>
  18 #include <linux/mod_devicetable.h>
  19 #include <linux/module.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/scatterlist.h>
  22 #include <linux/sys_soc.h>
  23
  24 #include "renesas_sdhi.h"
  25 #include "tmio_mmc.h"
  26
  27 #define DM_CM_DTRAN_MODE        0x820
  28 #define DM_CM_DTRAN_CTRL        0x828
  29 #define DM_CM_RST               0x830
  30 #define DM_CM_INFO1             0x840
  31 #define DM_CM_INFO1_MASK        0x848
  32 #define DM_CM_INFO2             0x850
  33 #define DM_CM_INFO2_MASK        0x858
  34 #define DM_DTRAN_ADDR           0x880
  35
  36 /* DM_CM_DTRAN_MODE */
  37 #define DTRAN_MODE_CH_NUM_CH0   0       /* "downstream" = for write commands */
  38 #define DTRAN_MODE_CH_NUM_CH1   BIT(16) /* "uptream" = for read commands */
  39 #define DTRAN_MODE_BUS_WID_TH   (BIT(5) | BIT(4))
  40 #define DTRAN_MODE_ADDR_MODE    BIT(0)  /* 1 = Increment address */
  41
  42 /* DM_CM_DTRAN_CTRL */
  43 #define DTRAN_CTRL_DM_START     BIT(0)
  44
  45 /* DM_CM_RST */
  46 #define RST_DTRANRST1           BIT(9)
  47 #define RST_DTRANRST0           BIT(8)
  48 #define RST_RESERVED_BITS       GENMASK_ULL(31, 0)
  49
  50 /* DM_CM_INFO1 and DM_CM_INFO1_MASK */
  51 #define INFO1_CLEAR             0
  52 #define INFO1_MASK_CLEAR        GENMASK_ULL(31, 0)
  53 #define INFO1_DTRANEND1         BIT(17)
  54 #define INFO1_DTRANEND0         BIT(16)
  55
  56 /* DM_CM_INFO2 and DM_CM_INFO2_MASK */
  57 #define INFO2_MASK_CLEAR        GENMASK_ULL(31, 0)
  58 #define INFO2_DTRANERR1         BIT(17)
  59 #define INFO2_DTRANERR0         BIT(16)
  60
  61 /*
  62  * Specification of this driver:
  63  * - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma
  64  * - Since this SDHI DMAC register set has 16 but 32-bit width, we
  65  *   need a custom accessor.
  66  */
  67
  68 static unsigned long global_flags;
  69 /*
  70  * Workaround for avoiding to use RX DMAC by multiple channels.
  71  * On R-Car H3 ES1.* and M3-W ES1.0, when multiple SDHI channels use
  72  * RX DMAC simultaneously, sometimes hundreds of bytes data are not
  73  * stored into the system memory even if the DMAC interrupt happened.
  74  * So, this driver then uses one RX DMAC channel only.
  75  */
  76 #define SDHI_INTERNAL_DMAC_ONE_RX_ONLY  0
  77 #define SDHI_INTERNAL_DMAC_RX_IN_USE    1
  78
  79 /* Definitions for sampling clocks */
  80 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
  81         {
  82                 .clk_rate = 0,
  83                 .tap = 0x00000300,
  84         },
  85 };
  86
  87 static const struct renesas_sdhi_of_data of_rcar_r8a7795_compatible = {
  88         .tmio_flags     = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
  89                           TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2 |
  90                           TMIO_MMC_HAVE_4TAP_HS400,
  91         .capabilities   = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
  92                           MMC_CAP_CMD23,
  93         .capabilities2  = MMC_CAP2_NO_WRITE_PROTECT,
  94         .bus_shift      = 2,
  95         .scc_offset     = 0x1000,
  96         .taps           = rcar_gen3_scc_taps,
  97         .taps_num       = ARRAY_SIZE(rcar_gen3_scc_taps),
  98         /* DMAC can handle 0xffffffff blk count but only 1 segment */
  99         .max_blk_count  = 0xffffffff,
 100         .max_segs       = 1,
 101 };
 102
 103 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
 104         .tmio_flags     = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
 105                           TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
 106         .capabilities   = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
 107                           MMC_CAP_CMD23,
 108         .capabilities2  = MMC_CAP2_NO_WRITE_PROTECT,
 109         .bus_shift      = 2,
 110         .scc_offset     = 0x1000,
 111         .taps           = rcar_gen3_scc_taps,
 112         .taps_num       = ARRAY_SIZE(rcar_gen3_scc_taps),
 113         /* DMAC can handle 0xffffffff blk count but only 1 segment */
 114         .max_blk_count  = 0xffffffff,
 115         .max_segs       = 1,
 116 };
 117
 118 static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = {
 119         { .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_r8a7795_compatible, },
 120         { .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_r8a7795_compatible, },
 121         { .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
 122         {},
 123 };
 124 MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match);
 125
 126 static void
 127 renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host *host,
 128                                     int addr, u64 val)
 129 {
 130         writeq(val, host->ctl + addr);
 131 }
 132
 133 static void
 134 renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host, bool enable)
 135 {
 136         struct renesas_sdhi *priv = host_to_priv(host);
 137
 138         if (!host->chan_tx || !host->chan_rx)
 139                 return;
 140
 141         if (!enable)
 142                 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1,
 143                                                     INFO1_CLEAR);
 144
 145         if (priv->dma_priv.enable)
 146                 priv->dma_priv.enable(host, enable);
 147 }
 148
 149 static void
 150 renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) {
 151         u64 val = RST_DTRANRST1 | RST_DTRANRST0;
 152
 153         renesas_sdhi_internal_dmac_enable_dma(host, false);
 154
 155         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
 156                                             RST_RESERVED_BITS & ~val);
 157         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
 158                                             RST_RESERVED_BITS | val);
 159
 160         clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
 161
 162         renesas_sdhi_internal_dmac_enable_dma(host, true);
 163 }
 164
 165 static void
 166 renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host *host) {
 167         struct renesas_sdhi *priv = host_to_priv(host);
 168
 169         tasklet_schedule(&priv->dma_priv.dma_complete);
 170 }
 171
 172 static void
 173 renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
 174                                      struct mmc_data *data)
 175 {
 176         struct scatterlist *sg = host->sg_ptr;
 177         u32 dtran_mode = DTRAN_MODE_BUS_WID_TH | DTRAN_MODE_ADDR_MODE;
 178
 179         if (!dma_map_sg(&host->pdev->dev, sg, host->sg_len,
 180                         mmc_get_dma_dir(data)))
 181                 goto force_pio;
 182
 183         /* This DMAC cannot handle if buffer is not 128-bytes alignment */
 184         if (!IS_ALIGNED(sg_dma_address(sg), 128))
 185                 goto force_pio_with_unmap;
 186
 187         if (data->flags & MMC_DATA_READ) {
 188                 dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
 189                 if (test_bit(SDHI_INTERNAL_DMAC_ONE_RX_ONLY, &global_flags) &&
 190                     test_and_set_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags))
 191                         goto force_pio_with_unmap;
 192         } else {
 193                 dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
 194         }
 195
 196         renesas_sdhi_internal_dmac_enable_dma(host, true);
 197
 198         /* set dma parameters */
 199         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_MODE,
 200                                             dtran_mode);
 201         renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
 202                                             sg_dma_address(sg));
 203
 204         return;
 205
 206 force_pio_with_unmap:
 207         dma_unmap_sg(&host->pdev->dev, sg, host->sg_len, mmc_get_dma_dir(data));
 208
 209 force_pio:
 210         host->force_pio = true;
 211         renesas_sdhi_internal_dmac_enable_dma(host, false);
 212 }
 213
 214 static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)
 215 {
 216         struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
 217
 218         tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
 219
 220         /* start the DMAC */
 221         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_CTRL,
 222                                             DTRAN_CTRL_DM_START);
 223 }
 224
 225 static bool renesas_sdhi_internal_dmac_complete(struct tmio_mmc_host *host)
 226 {
 227         enum dma_data_direction dir;
 228
 229         if (!host->data)
 230                 return false;
 231
 232         if (host->data->flags & MMC_DATA_READ)
 233                 dir = DMA_FROM_DEVICE;
 234         else
 235                 dir = DMA_TO_DEVICE;
 236
 237         renesas_sdhi_internal_dmac_enable_dma(host, false);
 238         dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir);
 239
 240         if (dir == DMA_FROM_DEVICE)
 241                 clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags);
 242
 243         return true;
 244 }
 245
 246 static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)
 247 {
 248         struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
 249
 250         spin_lock_irq(&host->lock);
 251         if (!renesas_sdhi_internal_dmac_complete(host))
 252                 goto out;
 253
 254         tmio_mmc_do_data_irq(host);
 255 out:
 256         spin_unlock_irq(&host->lock);
 257 }
 258
 259 static void
 260 renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host,
 261                                        struct tmio_mmc_data *pdata)
 262 {
 263         struct renesas_sdhi *priv = host_to_priv(host);
 264
 265         /* Disable DMAC interrupts, we don't use them */
 266         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1_MASK,
 267                                             INFO1_MASK_CLEAR);
 268         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO2_MASK,
 269                                             INFO2_MASK_CLEAR);
 270
 271         /* Each value is set to non-zero to assume "enabling" each DMA */
 272         host->chan_rx = host->chan_tx = (void *)0xdeadbeaf;
 273
 274         tasklet_init(&priv->dma_priv.dma_complete,
 275                      renesas_sdhi_internal_dmac_complete_tasklet_fn,
 276                      (unsigned long)host);
 277         tasklet_init(&host->dma_issue,
 278                      renesas_sdhi_internal_dmac_issue_tasklet_fn,
 279                      (unsigned long)host);
 280 }
 281
 282 static void
 283 renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host)
 284 {
 285         /* Each value is set to zero to assume "disabling" each DMA */
 286         host->chan_rx = host->chan_tx = NULL;
 287 }
 288
 289 static const struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = {
 290         .start = renesas_sdhi_internal_dmac_start_dma,
 291         .enable = renesas_sdhi_internal_dmac_enable_dma,
 292         .request = renesas_sdhi_internal_dmac_request_dma,
 293         .release = renesas_sdhi_internal_dmac_release_dma,
 294         .abort = renesas_sdhi_internal_dmac_abort_dma,
 295         .dataend = renesas_sdhi_internal_dmac_dataend_dma,
 296 };
 297
 298 /*
 299  * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
 300  * implementation as others may use a different implementation.
 301  */
 302 static const struct soc_device_attribute gen3_soc_whitelist[] = {
 303         /* specific ones */
 304         { .soc_id = "r8a7795", .revision = "ES1.*",
 305           .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
 306         { .soc_id = "r8a7796", .revision = "ES1.0",
 307           .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) },
 308         /* generic ones */
 309         { .soc_id = "r8a774a1" },
 310         { .soc_id = "r8a7795" },
 311         { .soc_id = "r8a7796" },
 312         { .soc_id = "r8a77965" },
 313         { .soc_id = "r8a77980" },
 314         { .soc_id = "r8a77995" },
 315         { /* sentinel */ }
 316 };
 317
 318 static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
 319 {
 320         const struct soc_device_attribute *soc = soc_device_match(gen3_soc_whitelist);
 321         struct device *dev = &pdev->dev;
 322
 323         if (!soc)
 324                 return -ENODEV;
 325
 326         global_flags |= (unsigned long)soc->data;
 327
 328         dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), GFP_KERNEL);
 329         if (!dev->dma_parms)
 330                 return -ENOMEM;
 331
 332         /* value is max of SD_SECCNT. Confirmed by HW engineers */
 333         dma_set_max_seg_size(dev, 0xffffffff);
 334
 335         return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
 336 }
 337
 338 static const struct dev_pm_ops renesas_sdhi_internal_dmac_dev_pm_ops = {
 339         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 340                                 pm_runtime_force_resume)
 341         SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
 342                            tmio_mmc_host_runtime_resume,
 343                            NULL)
 344 };
 345
 346 static struct platform_driver renesas_internal_dmac_sdhi_driver = {
 347         .driver         = {
 348                 .name   = "renesas_sdhi_internal_dmac",
 349                 .pm     = &renesas_sdhi_internal_dmac_dev_pm_ops,
 350                 .of_match_table = renesas_sdhi_internal_dmac_of_match,
 351         },
 352         .probe          = renesas_sdhi_internal_dmac_probe,
 353         .remove         = renesas_sdhi_remove,
 354 };
 355
 356 module_platform_driver(renesas_internal_dmac_sdhi_driver);
 357
 358 MODULE_DESCRIPTION("Renesas SDHI driver for internal DMAC");
 359 MODULE_AUTHOR("Yoshihiro Shimoda");
 360 MODULE_LICENSE("GPL v2");