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(32, 0) 49 50 /* DM_CM_INFO1 and DM_CM_INFO1_MASK */ 51 #define INFO1_CLEAR 0 52 #define INFO1_DTRANEND1 BIT(17) 53 #define INFO1_DTRANEND0 BIT(16) 54 55 /* DM_CM_INFO2 and DM_CM_INFO2_MASK */ 56 #define INFO2_DTRANERR1 BIT(17) 57 #define INFO2_DTRANERR0 BIT(16) 58 59 /* 60 * Specification of this driver: 61 * - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma 62 * - Since this SDHI DMAC register set has 16 but 32-bit width, we 63 * need a custom accessor. 64 */ 65 66 static unsigned long global_flags; 67 /* 68 * Workaround for avoiding to use RX DMAC by multiple channels. 69 * On R-Car H3 ES1.* and M3-W ES1.0, when multiple SDHI channels use 70 * RX DMAC simultaneously, sometimes hundreds of bytes data are not 71 * stored into the system memory even if the DMAC interrupt happened. 72 * So, this driver then uses one RX DMAC channel only. 73 */ 74 #define SDHI_INTERNAL_DMAC_ONE_RX_ONLY 0 75 #define SDHI_INTERNAL_DMAC_RX_IN_USE 1 76 77 /* Definitions for sampling clocks */ 78 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = { 79 { 80 .clk_rate = 0, 81 .tap = 0x00000300, 82 }, 83 }; 84 85 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = { 86 .tmio_flags = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL | 87 TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2, 88 .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ | 89 MMC_CAP_CMD23, 90 .bus_shift = 2, 91 .scc_offset = 0x1000, 92 .taps = rcar_gen3_scc_taps, 93 .taps_num = ARRAY_SIZE(rcar_gen3_scc_taps), 94 /* Gen3 SDHI DMAC can handle 0xffffffff blk count, but seg = 1 */ 95 .max_blk_count = 0xffffffff, 96 .max_segs = 1, 97 }; 98 99 static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = { 100 { .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_gen3_compatible, }, 101 { .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_gen3_compatible, }, 102 { .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, }, 103 {}, 104 }; 105 MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match); 106 107 static void 108 renesas_sdhi_internal_dmac_dm_write(struct tmio_mmc_host *host, 109 int addr, u64 val) 110 { 111 writeq(val, host->ctl + addr); 112 } 113 114 static void 115 renesas_sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host, bool enable) 116 { 117 struct renesas_sdhi *priv = host_to_priv(host); 118 119 if (!host->chan_tx || !host->chan_rx) 120 return; 121 122 if (!enable) 123 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_INFO1, 124 INFO1_CLEAR); 125 126 if (priv->dma_priv.enable) 127 priv->dma_priv.enable(host, enable); 128 } 129 130 static void 131 renesas_sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host) { 132 u64 val = RST_DTRANRST1 | RST_DTRANRST0; 133 134 renesas_sdhi_internal_dmac_enable_dma(host, false); 135 136 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST, 137 RST_RESERVED_BITS & ~val); 138 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_RST, 139 RST_RESERVED_BITS | val); 140 141 if (host->data && host->data->flags & MMC_DATA_READ) 142 clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags); 143 144 renesas_sdhi_internal_dmac_enable_dma(host, true); 145 } 146 147 static void 148 renesas_sdhi_internal_dmac_dataend_dma(struct tmio_mmc_host *host) { 149 struct renesas_sdhi *priv = host_to_priv(host); 150 151 tasklet_schedule(&priv->dma_priv.dma_complete); 152 } 153 154 static void 155 renesas_sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host, 156 struct mmc_data *data) 157 { 158 struct scatterlist *sg = host->sg_ptr; 159 u32 dtran_mode = DTRAN_MODE_BUS_WID_TH | DTRAN_MODE_ADDR_MODE; 160 enum dma_data_direction dir; 161 int ret; 162 163 /* This DMAC cannot handle if sg_len is not 1 */ 164 WARN_ON(host->sg_len > 1); 165 166 /* This DMAC cannot handle if buffer is not 8-bytes alignment */ 167 if (!IS_ALIGNED(sg->offset, 8)) 168 goto force_pio; 169 170 if (data->flags & MMC_DATA_READ) { 171 dtran_mode |= DTRAN_MODE_CH_NUM_CH1; 172 dir = DMA_FROM_DEVICE; 173 if (test_bit(SDHI_INTERNAL_DMAC_ONE_RX_ONLY, &global_flags) && 174 test_and_set_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags)) 175 goto force_pio; 176 } else { 177 dtran_mode |= DTRAN_MODE_CH_NUM_CH0; 178 dir = DMA_TO_DEVICE; 179 } 180 181 ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len, dir); 182 if (ret == 0) 183 goto force_pio; 184 185 renesas_sdhi_internal_dmac_enable_dma(host, true); 186 187 /* set dma parameters */ 188 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_MODE, 189 dtran_mode); 190 renesas_sdhi_internal_dmac_dm_write(host, DM_DTRAN_ADDR, 191 sg->dma_address); 192 193 return; 194 195 force_pio: 196 host->force_pio = true; 197 renesas_sdhi_internal_dmac_enable_dma(host, false); 198 } 199 200 static void renesas_sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg) 201 { 202 struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg; 203 204 tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND); 205 206 /* start the DMAC */ 207 renesas_sdhi_internal_dmac_dm_write(host, DM_CM_DTRAN_CTRL, 208 DTRAN_CTRL_DM_START); 209 } 210 211 static void renesas_sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg) 212 { 213 struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg; 214 enum dma_data_direction dir; 215 216 spin_lock_irq(&host->lock); 217 218 if (!host->data) 219 goto out; 220 221 if (host->data->flags & MMC_DATA_READ) 222 dir = DMA_FROM_DEVICE; 223 else 224 dir = DMA_TO_DEVICE; 225 226 renesas_sdhi_internal_dmac_enable_dma(host, false); 227 dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir); 228 229 if (dir == DMA_FROM_DEVICE) 230 clear_bit(SDHI_INTERNAL_DMAC_RX_IN_USE, &global_flags); 231 232 tmio_mmc_do_data_irq(host); 233 out: 234 spin_unlock_irq(&host->lock); 235 } 236 237 static void 238 renesas_sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host, 239 struct tmio_mmc_data *pdata) 240 { 241 struct renesas_sdhi *priv = host_to_priv(host); 242 243 /* Each value is set to non-zero to assume "enabling" each DMA */ 244 host->chan_rx = host->chan_tx = (void *)0xdeadbeaf; 245 246 tasklet_init(&priv->dma_priv.dma_complete, 247 renesas_sdhi_internal_dmac_complete_tasklet_fn, 248 (unsigned long)host); 249 tasklet_init(&host->dma_issue, 250 renesas_sdhi_internal_dmac_issue_tasklet_fn, 251 (unsigned long)host); 252 } 253 254 static void 255 renesas_sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host) 256 { 257 /* Each value is set to zero to assume "disabling" each DMA */ 258 host->chan_rx = host->chan_tx = NULL; 259 } 260 261 static const struct tmio_mmc_dma_ops renesas_sdhi_internal_dmac_dma_ops = { 262 .start = renesas_sdhi_internal_dmac_start_dma, 263 .enable = renesas_sdhi_internal_dmac_enable_dma, 264 .request = renesas_sdhi_internal_dmac_request_dma, 265 .release = renesas_sdhi_internal_dmac_release_dma, 266 .abort = renesas_sdhi_internal_dmac_abort_dma, 267 .dataend = renesas_sdhi_internal_dmac_dataend_dma, 268 }; 269 270 /* 271 * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC 272 * implementation as others may use a different implementation. 273 */ 274 static const struct soc_device_attribute gen3_soc_whitelist[] = { 275 { .soc_id = "r8a7795", .revision = "ES1.*", 276 .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) }, 277 { .soc_id = "r8a7795", .revision = "ES2.0" }, 278 { .soc_id = "r8a7796", .revision = "ES1.0", 279 .data = (void *)BIT(SDHI_INTERNAL_DMAC_ONE_RX_ONLY) }, 280 { .soc_id = "r8a77995", .revision = "ES1.0" }, 281 { /* sentinel */ } 282 }; 283 284 static int renesas_sdhi_internal_dmac_probe(struct platform_device *pdev) 285 { 286 const struct soc_device_attribute *soc = soc_device_match(gen3_soc_whitelist); 287 288 if (!soc) 289 return -ENODEV; 290 291 global_flags |= (unsigned long)soc->data; 292 293 return renesas_sdhi_probe(pdev, &renesas_sdhi_internal_dmac_dma_ops); 294 } 295 296 static const struct dev_pm_ops renesas_sdhi_internal_dmac_dev_pm_ops = { 297 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 298 pm_runtime_force_resume) 299 SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend, 300 tmio_mmc_host_runtime_resume, 301 NULL) 302 }; 303 304 static struct platform_driver renesas_internal_dmac_sdhi_driver = { 305 .driver = { 306 .name = "renesas_sdhi_internal_dmac", 307 .pm = &renesas_sdhi_internal_dmac_dev_pm_ops, 308 .of_match_table = renesas_sdhi_internal_dmac_of_match, 309 }, 310 .probe = renesas_sdhi_internal_dmac_probe, 311 .remove = renesas_sdhi_remove, 312 }; 313 314 module_platform_driver(renesas_internal_dmac_sdhi_driver); 315 316 MODULE_DESCRIPTION("Renesas SDHI driver for internal DMAC"); 317 MODULE_AUTHOR("Yoshihiro Shimoda"); 318 MODULE_LICENSE("GPL v2"); 319