drivers/dma/dw/idma32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2013,2018,2020-2021 Intel Corporation
   3
   4 #include <linux/bitops.h>
   5 #include <linux/dmaengine.h>
   6 #include <linux/errno.h>
   7 #include <linux/io.h>
   8 #include <linux/pci.h>
   9 #include <linux/slab.h>
  10 #include <linux/types.h>
  11
  12 #include "internal.h"
  13
  14 #define DMA_CTL_CH(x)                   (0x1000 + (x) * 4)
  15 #define DMA_SRC_ADDR_FILLIN(x)          (0x1100 + (x) * 4)
  16 #define DMA_DST_ADDR_FILLIN(x)          (0x1200 + (x) * 4)
  17 #define DMA_XBAR_SEL(x)                 (0x1300 + (x) * 4)
  18 #define DMA_REGACCESS_CHID_CFG          (0x1400)
  19
  20 #define CTL_CH_TRANSFER_MODE_MASK       GENMASK(1, 0)
  21 #define CTL_CH_TRANSFER_MODE_S2S        0
  22 #define CTL_CH_TRANSFER_MODE_S2D        1
  23 #define CTL_CH_TRANSFER_MODE_D2S        2
  24 #define CTL_CH_TRANSFER_MODE_D2D        3
  25 #define CTL_CH_RD_RS_MASK               GENMASK(4, 3)
  26 #define CTL_CH_WR_RS_MASK               GENMASK(6, 5)
  27 #define CTL_CH_RD_NON_SNOOP_BIT         BIT(8)
  28 #define CTL_CH_WR_NON_SNOOP_BIT         BIT(9)
  29
  30 #define XBAR_SEL_DEVID_MASK             GENMASK(15, 0)
  31 #define XBAR_SEL_RX_TX_BIT              BIT(16)
  32 #define XBAR_SEL_RX_TX_SHIFT            16
  33
  34 #define REGACCESS_CHID_MASK             GENMASK(2, 0)
  35
  36 static unsigned int idma32_get_slave_devfn(struct dw_dma_chan *dwc)
  37 {
  38         struct device *slave = dwc->chan.slave;
  39
  40         if (!slave || !dev_is_pci(slave))
  41                 return 0;
  42
  43         return to_pci_dev(slave)->devfn;
  44 }
  45
  46 static void idma32_initialize_chan_xbar(struct dw_dma_chan *dwc)
  47 {
  48         struct dw_dma *dw = to_dw_dma(dwc->chan.device);
  49         void __iomem *misc = __dw_regs(dw);
  50         u32 cfghi = 0, cfglo = 0;
  51         u8 dst_id, src_id;
  52         u32 value;
  53
  54         /* DMA Channel ID Configuration register must be programmed first */
  55         value = readl(misc + DMA_REGACCESS_CHID_CFG);
  56
  57         value &= ~REGACCESS_CHID_MASK;
  58         value |= dwc->chan.chan_id;
  59
  60         writel(value, misc + DMA_REGACCESS_CHID_CFG);
  61
  62         /* Configure channel attributes */
  63         value = readl(misc + DMA_CTL_CH(dwc->chan.chan_id));
  64
  65         value &= ~(CTL_CH_RD_NON_SNOOP_BIT | CTL_CH_WR_NON_SNOOP_BIT);
  66         value &= ~(CTL_CH_RD_RS_MASK | CTL_CH_WR_RS_MASK);
  67         value &= ~CTL_CH_TRANSFER_MODE_MASK;
  68
  69         switch (dwc->direction) {
  70         case DMA_MEM_TO_DEV:
  71                 value |= CTL_CH_TRANSFER_MODE_D2S;
  72                 value |= CTL_CH_WR_NON_SNOOP_BIT;
  73                 break;
  74         case DMA_DEV_TO_MEM:
  75                 value |= CTL_CH_TRANSFER_MODE_S2D;
  76                 value |= CTL_CH_RD_NON_SNOOP_BIT;
  77                 break;
  78         default:
  79                 /*
  80                  * Memory-to-Memory and Device-to-Device are ignored for now.
  81                  *
  82                  * For Memory-to-Memory transfers we would need to set mode
  83                  * and disable snooping on both sides.
  84                  */
  85                 return;
  86         }
  87
  88         writel(value, misc + DMA_CTL_CH(dwc->chan.chan_id));
  89
  90         /* Configure crossbar selection */
  91         value = readl(misc + DMA_XBAR_SEL(dwc->chan.chan_id));
  92
  93         /* DEVFN selection */
  94         value &= ~XBAR_SEL_DEVID_MASK;
  95         value |= idma32_get_slave_devfn(dwc);
  96
  97         switch (dwc->direction) {
  98         case DMA_MEM_TO_DEV:
  99                 value |= XBAR_SEL_RX_TX_BIT;
 100                 break;
 101         case DMA_DEV_TO_MEM:
 102                 value &= ~XBAR_SEL_RX_TX_BIT;
 103                 break;
 104         default:
 105                 /* Memory-to-Memory and Device-to-Device are ignored for now */
 106                 return;
 107         }
 108
 109         writel(value, misc + DMA_XBAR_SEL(dwc->chan.chan_id));
 110
 111         /* Configure DMA channel low and high registers */
 112         switch (dwc->direction) {
 113         case DMA_MEM_TO_DEV:
 114                 dst_id = dwc->chan.chan_id;
 115                 src_id = dwc->dws.src_id;
 116                 break;
 117         case DMA_DEV_TO_MEM:
 118                 dst_id = dwc->dws.dst_id;
 119                 src_id = dwc->chan.chan_id;
 120                 break;
 121         default:
 122                 /* Memory-to-Memory and Device-to-Device are ignored for now */
 123                 return;
 124         }
 125
 126         /* Set default burst alignment */
 127         cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;
 128
 129         /* Low 4 bits of the request lines */
 130         cfghi |= IDMA32C_CFGH_DST_PER(dst_id & 0xf);
 131         cfghi |= IDMA32C_CFGH_SRC_PER(src_id & 0xf);
 132
 133         /* Request line extension (2 bits) */
 134         cfghi |= IDMA32C_CFGH_DST_PER_EXT(dst_id >> 4 & 0x3);
 135         cfghi |= IDMA32C_CFGH_SRC_PER_EXT(src_id >> 4 & 0x3);
 136
 137         channel_writel(dwc, CFG_LO, cfglo);
 138         channel_writel(dwc, CFG_HI, cfghi);
 139 }
 140
 141 static void idma32_initialize_chan_generic(struct dw_dma_chan *dwc)
 142 {
 143         u32 cfghi = 0;
 144         u32 cfglo = 0;
 145
 146         /* Set default burst alignment */
 147         cfglo |= IDMA32C_CFGL_DST_BURST_ALIGN | IDMA32C_CFGL_SRC_BURST_ALIGN;
 148
 149         /* Low 4 bits of the request lines */
 150         cfghi |= IDMA32C_CFGH_DST_PER(dwc->dws.dst_id & 0xf);
 151         cfghi |= IDMA32C_CFGH_SRC_PER(dwc->dws.src_id & 0xf);
 152
 153         /* Request line extension (2 bits) */
 154         cfghi |= IDMA32C_CFGH_DST_PER_EXT(dwc->dws.dst_id >> 4 & 0x3);
 155         cfghi |= IDMA32C_CFGH_SRC_PER_EXT(dwc->dws.src_id >> 4 & 0x3);
 156
 157         channel_writel(dwc, CFG_LO, cfglo);
 158         channel_writel(dwc, CFG_HI, cfghi);
 159 }
 160
 161 static void idma32_suspend_chan(struct dw_dma_chan *dwc, bool drain)
 162 {
 163         u32 cfglo = channel_readl(dwc, CFG_LO);
 164
 165         if (drain)
 166                 cfglo |= IDMA32C_CFGL_CH_DRAIN;
 167
 168         channel_writel(dwc, CFG_LO, cfglo | DWC_CFGL_CH_SUSP);
 169 }
 170
 171 static void idma32_resume_chan(struct dw_dma_chan *dwc, bool drain)
 172 {
 173         u32 cfglo = channel_readl(dwc, CFG_LO);
 174
 175         if (drain)
 176                 cfglo &= ~IDMA32C_CFGL_CH_DRAIN;
 177
 178         channel_writel(dwc, CFG_LO, cfglo & ~DWC_CFGL_CH_SUSP);
 179 }
 180
 181 static u32 idma32_bytes2block(struct dw_dma_chan *dwc,
 182                               size_t bytes, unsigned int width, size_t *len)
 183 {
 184         u32 block;
 185
 186         if (bytes > dwc->block_size) {
 187                 block = dwc->block_size;
 188                 *len = dwc->block_size;
 189         } else {
 190                 block = bytes;
 191                 *len = bytes;
 192         }
 193
 194         return block;
 195 }
 196
 197 static size_t idma32_block2bytes(struct dw_dma_chan *dwc, u32 block, u32 width)
 198 {
 199         return IDMA32C_CTLH_BLOCK_TS(block);
 200 }
 201
 202 static inline u8 idma32_encode_maxburst(u32 maxburst)
 203 {
 204         return maxburst > 1 ? fls(maxburst) - 1 : 0;
 205 }
 206
 207 static u32 idma32_prepare_ctllo(struct dw_dma_chan *dwc)
 208 {
 209         struct dma_slave_config *sconfig = &dwc->dma_sconfig;
 210         u8 smsize = 0, dmsize = 0;
 211
 212         if (dwc->direction == DMA_MEM_TO_DEV)
 213                 dmsize = idma32_encode_maxburst(sconfig->dst_maxburst);
 214         else if (dwc->direction == DMA_DEV_TO_MEM)
 215                 smsize = idma32_encode_maxburst(sconfig->src_maxburst);
 216
 217         return DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN |
 218                DWC_CTLL_DST_MSIZE(dmsize) | DWC_CTLL_SRC_MSIZE(smsize);
 219 }
 220
 221 static void idma32_set_device_name(struct dw_dma *dw, int id)
 222 {
 223         snprintf(dw->name, sizeof(dw->name), "idma32:dmac%d", id);
 224 }
 225
 226 /*
 227  * Program FIFO size of channels.
 228  *
 229  * By default full FIFO (512 bytes) is assigned to channel 0. Here we
 230  * slice FIFO on equal parts between channels.
 231  */
 232 static void idma32_fifo_partition(struct dw_dma *dw)
 233 {
 234         u64 value = IDMA32C_FP_PSIZE_CH0(64) | IDMA32C_FP_PSIZE_CH1(64) |
 235                     IDMA32C_FP_UPDATE;
 236         u64 fifo_partition = 0;
 237
 238         /* Fill FIFO_PARTITION low bits (Channels 0..1, 4..5) */
 239         fifo_partition |= value << 0;
 240
 241         /* Fill FIFO_PARTITION high bits (Channels 2..3, 6..7) */
 242         fifo_partition |= value << 32;
 243
 244         /* Program FIFO Partition registers - 64 bytes per channel */
 245         idma32_writeq(dw, FIFO_PARTITION1, fifo_partition);
 246         idma32_writeq(dw, FIFO_PARTITION0, fifo_partition);
 247 }
 248
 249 static void idma32_disable(struct dw_dma *dw)
 250 {
 251         do_dw_dma_off(dw);
 252         idma32_fifo_partition(dw);
 253 }
 254
 255 static void idma32_enable(struct dw_dma *dw)
 256 {
 257         idma32_fifo_partition(dw);
 258         do_dw_dma_on(dw);
 259 }
 260
 261 int idma32_dma_probe(struct dw_dma_chip *chip)
 262 {
 263         struct dw_dma *dw;
 264
 265         dw = devm_kzalloc(chip->dev, sizeof(*dw), GFP_KERNEL);
 266         if (!dw)
 267                 return -ENOMEM;
 268
 269         /* Channel operations */
 270         if (chip->pdata->quirks & DW_DMA_QUIRK_XBAR_PRESENT)
 271                 dw->initialize_chan = idma32_initialize_chan_xbar;
 272         else
 273                 dw->initialize_chan = idma32_initialize_chan_generic;
 274         dw->suspend_chan = idma32_suspend_chan;
 275         dw->resume_chan = idma32_resume_chan;
 276         dw->prepare_ctllo = idma32_prepare_ctllo;
 277         dw->bytes2block = idma32_bytes2block;
 278         dw->block2bytes = idma32_block2bytes;
 279
 280         /* Device operations */
 281         dw->set_device_name = idma32_set_device_name;
 282         dw->disable = idma32_disable;
 283         dw->enable = idma32_enable;
 284
 285         chip->dw = dw;
 286         return do_dma_probe(chip);
 287 }
 288 EXPORT_SYMBOL_GPL(idma32_dma_probe);
 289
 290 int idma32_dma_remove(struct dw_dma_chip *chip)
 291 {
 292         return do_dma_remove(chip);
 293 }
 294 EXPORT_SYMBOL_GPL(idma32_dma_remove);