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/device.h>
  13 #include <linux/dma-mapping.h>
  14 #include <linux/io-64-nonatomic-hi-lo.h>
  15 #include <linux/mfd/tmio.h>
  16 #include <linux/mmc/host.h>
  17 #include <linux/mod_devicetable.h>
  18 #include <linux/module.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/scatterlist.h>
  21 #include <linux/sys_soc.h>
  22
  23 #include "renesas_sdhi.h"
  24 #include "tmio_mmc.h"
  25
  26 #define DM_CM_DTRAN_MODE        0x820
  27 #define DM_CM_DTRAN_CTRL        0x828
  28 #define DM_CM_RST               0x830
  29 #define DM_CM_INFO1             0x840
  30 #define DM_CM_INFO1_MASK        0x848
  31 #define DM_CM_INFO2             0x850
  32 #define DM_CM_INFO2_MASK        0x858
  33 #define DM_DTRAN_ADDR           0x880
  34
  35 /* DM_CM_DTRAN_MODE */
  36 #define DTRAN_MODE_CH_NUM_CH0   0       /* "downstream" = for write commands */
  37 #define DTRAN_MODE_CH_NUM_CH1   BIT(16) /* "uptream" = for read commands */
  38 #define DTRAN_MODE_BUS_WID_TH   (BIT(5) | BIT(4))
  39 #define DTRAN_MODE_ADDR_MODE    BIT(0)  /* 1 = Increment address */
  40
  41 /* DM_CM_DTRAN_CTRL */
  42 #define DTRAN_CTRL_DM_START     BIT(0)
  43
  44 /* DM_CM_RST */
  45 #define RST_DTRANRST1           BIT(9)
  46 #define RST_DTRANRST0           BIT(8)
  47 #define RST_RESERVED_BITS       GENMASK_ULL(31, 0)
  48
  49 /* DM_CM_INFO1 and DM_CM_INFO1_MASK */
  50 #define INFO1_CLEAR             0
  51 #define INFO1_DTRANEND1         BIT(17)
  52 #define INFO1_DTRANEND0         BIT(16)
  53
  54 /* DM_CM_INFO2 and DM_CM_INFO2_MASK */
  55 #define INFO2_DTRANERR1         BIT(17)
  56 #define INFO2_DTRANERR0         BIT(16)
  57
  58 /*
  59  * Specification of this driver:
  60  * - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma
  61  * - Since this SDHI DMAC register set has 16 but 32-bit width, we
  62  *   need a custom accessor.
  63  */
  64
  65 /* Definitions for sampling clocks */
  66 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
  67         {
  68                 .clk_rate = 0,
  69                 .tap = 0x00000300,
  70         },
  71 };
  72
  73 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
  74         .tmio_flags     = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE |
  75                           TMIO_MMC_CLK_ACTUAL | TMIO_MMC_HAVE_CBSY |
  76                           TMIO_MMC_MIN_RCAR2,
  77         .capabilities   = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
  78                           MMC_CAP_CMD23,
  79         .bus_shift      = 2,
  80         .scc_offset     = 0x1000,
  81         .taps           = rcar_gen3_scc_taps,
  82         .taps_num       = ARRAY_SIZE(rcar_gen3_scc_taps),
  83         /* Gen3 SDHI DMAC can handle 0xffffffff blk count, but seg = 1 */
  84         .max_blk_count  = 0xffffffff,
  85         .max_segs       = 1,
  86 };
  87
  88 static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = {
  89         { .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_gen3_compatible, },
  90         { .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_gen3_compatible, },
  91         {},
  92 };
  93 MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match);
  94
  95 static void
  96 renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host *host,
  97                                     int addr, u64 val)
  98 {
  99         writeq(val, host->ctl + addr);
 100 }
 101
 102 static void
 103 renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host, bool enable)
 104 {
 105         if (!host->chan_tx || !host->chan_rx)
 106                 return;
 107
 108         if (!enable)
 109                 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1,
 110                                                     INFO1_CLEAR);
 111
 112         if (host->dma->enable)
 113                 host->dma->enable(host, enable);
 114 }
 115
 116 static void
 117 renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) {
 118         u64 val = RST_DTRANRST1 | RST_DTRANRST0;
 119
 120         renesas_sdhi_internal_dmac_enable_dma(host, false);
 121
 122         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
 123                                             RST_RESERVED_BITS & ~val);
 124         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST,
 125                                             RST_RESERVED_BITS | val);
 126
 127         renesas_sdhi_internal_dmac_enable_dma(host, true);
 128 }
 129
 130 static void
 131 renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host *host) {
 132         tasklet_schedule(&host->dma_complete);
 133 }
 134
 135 static void
 136 renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
 137                                      struct mmc_data *data)
 138 {
 139         struct scatterlist *sg = host->sg_ptr;
 140         u32 dtran_mode = DTRAN_MODE_BUS_WID_TH | DTRAN_MODE_ADDR_MODE;
 141         enum dma_data_direction dir;
 142         int ret;
 143         u32 irq_mask;
 144
 145         /* This DMAC cannot handle if sg_len is not 1 */
 146         WARN_ON(host->sg_len > 1);
 147
 148         /* This DMAC cannot handle if buffer is not 8-bytes alignment */
 149         if (!IS_ALIGNED(sg->offset, 8))
 150                 goto force_pio;
 151
 152         if (data->flags & MMC_DATA_READ) {
 153                 dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
 154                 dir = DMA_FROM_DEVICE;
 155                 irq_mask = TMIO_STAT_RXRDY;
 156         } else {
 157                 dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
 158                 dir = DMA_TO_DEVICE;
 159                 irq_mask = TMIO_STAT_TXRQ;
 160         }
 161
 162         ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len, dir);
 163         if (ret == 0)
 164                 goto force_pio;
 165
 166         renesas_sdhi_internal_dmac_enable_dma(host, true);
 167
 168         /* disable PIO irqs to avoid "PIO IRQ in DMA mode!" */
 169         tmio_mmc_disable_mmc_irqs(host, irq_mask);
 170
 171         /* set dma parameters */
 172         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_MODE,
 173                                             dtran_mode);
 174         renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR,
 175                                             sg->dma_address);
 176
 177         return;
 178
 179 force_pio:
 180         host->force_pio = true;
 181         renesas_sdhi_internal_dmac_enable_dma(host, false);
 182 }
 183
 184 static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)
 185 {
 186         struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
 187
 188         tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
 189
 190         /* start the DMAC */
 191         renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_CTRL,
 192                                             DTRAN_CTRL_DM_START);
 193 }
 194
 195 static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)
 196 {
 197         struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
 198         enum dma_data_direction dir;
 199
 200         spin_lock_irq(&host->lock);
 201
 202         if (!host->data)
 203                 goto out;
 204
 205         if (host->data->flags & MMC_DATA_READ)
 206                 dir = DMA_FROM_DEVICE;
 207         else
 208                 dir = DMA_TO_DEVICE;
 209
 210         renesas_sdhi_internal_dmac_enable_dma(host, false);
 211         dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir);
 212
 213         tmio_mmc_do_data_irq(host);
 214 out:
 215         spin_unlock_irq(&host->lock);
 216 }
 217
 218 static void
 219 renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host,
 220                                        struct tmio_mmc_data *pdata)
 221 {
 222         /* Each value is set to non-zero to assume "enabling" each DMA */
 223         host->chan_rx = host->chan_tx = (void *)0xdeadbeaf;
 224
 225         tasklet_init(&host->dma_complete,
 226                      renesas_sdhi_internal_dmac_complete_tasklet_fn,
 227                      (unsigned long)host);
 228         tasklet_init(&host->dma_issue,
 229                      renesas_sdhi_internal_dmac_issue_tasklet_fn,
 230                      (unsigned long)host);
 231 }
 232
 233 static void
 234 renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host)
 235 {
 236         /* Each value is set to zero to assume "disabling" each DMA */
 237         host->chan_rx = host->chan_tx = NULL;
 238 }
 239
 240 static const struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = {
 241         .start = renesas_sdhi_internal_dmac_start_dma,
 242         .enable = renesas_sdhi_internal_dmac_enable_dma,
 243         .request = renesas_sdhi_internal_dmac_request_dma,
 244         .release = renesas_sdhi_internal_dmac_release_dma,
 245         .abort = renesas_sdhi_internal_dmac_abort_dma,
 246         .dataend = renesas_sdhi_internal_dmac_dataend_dma,
 247 };
 248
 249 /*
 250  * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
 251  * implementation as others may use a different implementation.
 252  */
 253 static const struct soc_device_attribute gen3_soc_whitelist[] = {
 254         { .soc_id = "r8a7795", .revision = "ES1.*" },
 255         { .soc_id = "r8a7795", .revision = "ES2.0" },
 256         { .soc_id = "r8a7796", .revision = "ES1.0" },
 257         { /* sentinel */ }
 258 };
 259
 260 static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev)
 261 {
 262         if (!soc_device_match(gen3_soc_whitelist))
 263                 return -ENODEV;
 264
 265         return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops);
 266 }
 267
 268 static const struct dev_pm_ops renesas_sdhi_internal_dmac_dev_pm_ops = {
 269         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 270                                 pm_runtime_force_resume)
 271         SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
 272                            tmio_mmc_host_runtime_resume,
 273                            NULL)
 274 };
 275
 276 static struct platform_driver renesas_internal_dmac_sdhi_driver = {
 277         .driver         = {
 278                 .name   = "renesas_sdhi_internal_dmac",
 279                 .pm     = &renesas_sdhi_internal_dmac_dev_pm_ops,
 280                 .of_match_table = renesas_sdhi_internal_dmac_of_match,
 281         },
 282         .probe          = renesas_sdhi_internal_dmac_probe,
 283         .remove         = renesas_sdhi_remove,
 284 };
 285
 286 module_platform_driver(renesas_internal_dmac_sdhi_driver);
 287
 288 MODULE_DESCRIPTION("Renesas SDHI driver for internal DMAC");
 289 MODULE_AUTHOR("Yoshihiro Shimoda");
 290 MODULE_LICENSE("GPL v2");