drivers/mtd/hyperbus/hbmc-am654.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/
   4 // Author: Vignesh Raghavendra <vigneshr@ti.com>
   5
   6 #include <linux/completion.h>
   7 #include <linux/dma-direction.h>
   8 #include <linux/dma-mapping.h>
   9 #include <linux/dmaengine.h>
  10 #include <linux/err.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/mtd/cfi.h>
  14 #include <linux/mtd/hyperbus.h>
  15 #include <linux/mtd/mtd.h>
  16 #include <linux/mux/consumer.h>
  17 #include <linux/of.h>
  18 #include <linux/of_address.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/sched/task_stack.h>
  21 #include <linux/types.h>
  22
  23 #define AM654_HBMC_CALIB_COUNT 25
  24
  25 struct am654_hbmc_device_priv {
  26         struct completion rx_dma_complete;
  27         phys_addr_t device_base;
  28         struct hyperbus_ctlr *ctlr;
  29         struct dma_chan *rx_chan;
  30 };
  31
  32 struct am654_hbmc_priv {
  33         struct hyperbus_ctlr ctlr;
  34         struct hyperbus_device hbdev;
  35         struct mux_control *mux_ctrl;
  36 };
  37
  38 static int am654_hbmc_calibrate(struct hyperbus_device *hbdev)
  39 {
  40         struct map_info *map = &hbdev->map;
  41         struct cfi_private cfi;
  42         int count = AM654_HBMC_CALIB_COUNT;
  43         int pass_count = 0;
  44         int ret;
  45
  46         cfi.interleave = 1;
  47         cfi.device_type = CFI_DEVICETYPE_X16;
  48         cfi_send_gen_cmd(0xF0, 0, 0, map, &cfi, cfi.device_type, NULL);
  49         cfi_send_gen_cmd(0x98, 0x55, 0, map, &cfi, cfi.device_type, NULL);
  50
  51         while (count--) {
  52                 ret = cfi_qry_present(map, 0, &cfi);
  53                 if (ret)
  54                         pass_count++;
  55                 else
  56                         pass_count = 0;
  57                 if (pass_count == 5)
  58                         break;
  59         }
  60
  61         cfi_qry_mode_off(0, map, &cfi);
  62
  63         return ret;
  64 }
  65
  66 static void am654_hbmc_dma_callback(void *param)
  67 {
  68         struct am654_hbmc_device_priv *priv = param;
  69
  70         complete(&priv->rx_dma_complete);
  71 }
  72
  73 static int am654_hbmc_dma_read(struct am654_hbmc_device_priv *priv, void *to,
  74                                unsigned long from, ssize_t len)
  75
  76 {
  77         enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
  78         struct dma_chan *rx_chan = priv->rx_chan;
  79         struct dma_async_tx_descriptor *tx;
  80         dma_addr_t dma_dst, dma_src;
  81         dma_cookie_t cookie;
  82         int ret;
  83
  84         if (!priv->rx_chan || !virt_addr_valid(to) || object_is_on_stack(to))
  85                 return -EINVAL;
  86
  87         dma_dst = dma_map_single(rx_chan->device->dev, to, len, DMA_FROM_DEVICE);
  88         if (dma_mapping_error(rx_chan->device->dev, dma_dst)) {
  89                 dev_dbg(priv->ctlr->dev, "DMA mapping failed\n");
  90                 return -EIO;
  91         }
  92
  93         dma_src = priv->device_base + from;
  94         tx = dmaengine_prep_dma_memcpy(rx_chan, dma_dst, dma_src, len, flags);
  95         if (!tx) {
  96                 dev_err(priv->ctlr->dev, "device_prep_dma_memcpy error\n");
  97                 ret = -EIO;
  98                 goto unmap_dma;
  99         }
 100
 101         reinit_completion(&priv->rx_dma_complete);
 102         tx->callback = am654_hbmc_dma_callback;
 103         tx->callback_param = priv;
 104         cookie = dmaengine_submit(tx);
 105
 106         ret = dma_submit_error(cookie);
 107         if (ret) {
 108                 dev_err(priv->ctlr->dev, "dma_submit_error %d\n", cookie);
 109                 goto unmap_dma;
 110         }
 111
 112         dma_async_issue_pending(rx_chan);
 113         if (!wait_for_completion_timeout(&priv->rx_dma_complete,  msecs_to_jiffies(len + 1000))) {
 114                 dmaengine_terminate_sync(rx_chan);
 115                 dev_err(priv->ctlr->dev, "DMA wait_for_completion_timeout\n");
 116                 ret = -ETIMEDOUT;
 117         }
 118
 119 unmap_dma:
 120         dma_unmap_single(rx_chan->device->dev, dma_dst, len, DMA_FROM_DEVICE);
 121         return ret;
 122 }
 123
 124 static void am654_hbmc_read(struct hyperbus_device *hbdev, void *to,
 125                             unsigned long from, ssize_t len)
 126 {
 127         struct am654_hbmc_device_priv *priv = hbdev->priv;
 128
 129         if (len < SZ_1K || am654_hbmc_dma_read(priv, to, from, len))
 130                 memcpy_fromio(to, hbdev->map.virt + from, len);
 131 }
 132
 133 static const struct hyperbus_ops am654_hbmc_ops = {
 134         .calibrate = am654_hbmc_calibrate,
 135         .copy_from = am654_hbmc_read,
 136 };
 137
 138 static int am654_hbmc_request_mmap_dma(struct am654_hbmc_device_priv *priv)
 139 {
 140         struct dma_chan *rx_chan;
 141         dma_cap_mask_t mask;
 142
 143         dma_cap_zero(mask);
 144         dma_cap_set(DMA_MEMCPY, mask);
 145
 146         rx_chan = dma_request_chan_by_mask(&mask);
 147         if (IS_ERR(rx_chan)) {
 148                 if (PTR_ERR(rx_chan) == -EPROBE_DEFER)
 149                         return -EPROBE_DEFER;
 150                 dev_dbg(priv->ctlr->dev, "No DMA channel available\n");
 151                 return 0;
 152         }
 153         priv->rx_chan = rx_chan;
 154         init_completion(&priv->rx_dma_complete);
 155
 156         return 0;
 157 }
 158
 159 static int am654_hbmc_probe(struct platform_device *pdev)
 160 {
 161         struct device_node *np = pdev->dev.of_node;
 162         struct am654_hbmc_device_priv *dev_priv;
 163         struct device *dev = &pdev->dev;
 164         struct am654_hbmc_priv *priv;
 165         struct resource res;
 166         int ret;
 167
 168         priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 169         if (!priv)
 170                 return -ENOMEM;
 171
 172         platform_set_drvdata(pdev, priv);
 173
 174         priv->hbdev.np = of_get_next_child(np, NULL);
 175         ret = of_address_to_resource(priv->hbdev.np, 0, &res);
 176         if (ret)
 177                 return ret;
 178
 179         if (of_property_read_bool(dev->of_node, "mux-controls")) {
 180                 struct mux_control *control = devm_mux_control_get(dev, NULL);
 181
 182                 if (IS_ERR(control))
 183                         return PTR_ERR(control);
 184
 185                 ret = mux_control_select(control, 1);
 186                 if (ret) {
 187                         dev_err(dev, "Failed to select HBMC mux\n");
 188                         return ret;
 189                 }
 190                 priv->mux_ctrl = control;
 191         }
 192
 193         priv->hbdev.map.size = resource_size(&res);
 194         priv->hbdev.map.virt = devm_ioremap_resource(dev, &res);
 195         if (IS_ERR(priv->hbdev.map.virt))
 196                 return PTR_ERR(priv->hbdev.map.virt);
 197
 198         priv->ctlr.dev = dev;
 199         priv->ctlr.ops = &am654_hbmc_ops;
 200         priv->hbdev.ctlr = &priv->ctlr;
 201
 202         dev_priv = devm_kzalloc(dev, sizeof(*dev_priv), GFP_KERNEL);
 203         if (!dev_priv) {
 204                 ret = -ENOMEM;
 205                 goto disable_mux;
 206         }
 207
 208         priv->hbdev.priv = dev_priv;
 209         dev_priv->device_base = res.start;
 210         dev_priv->ctlr = &priv->ctlr;
 211
 212         ret = am654_hbmc_request_mmap_dma(dev_priv);
 213         if (ret)
 214                 goto disable_mux;
 215
 216         ret = hyperbus_register_device(&priv->hbdev);
 217         if (ret) {
 218                 dev_err(dev, "failed to register controller\n");
 219                 goto release_dma;
 220         }
 221
 222         return 0;
 223 release_dma:
 224         if (dev_priv->rx_chan)
 225                 dma_release_channel(dev_priv->rx_chan);
 226 disable_mux:
 227         if (priv->mux_ctrl)
 228                 mux_control_deselect(priv->mux_ctrl);
 229         return ret;
 230 }
 231
 232 static int am654_hbmc_remove(struct platform_device *pdev)
 233 {
 234         struct am654_hbmc_priv *priv = platform_get_drvdata(pdev);
 235         struct am654_hbmc_device_priv *dev_priv = priv->hbdev.priv;
 236         int ret;
 237
 238         ret = hyperbus_unregister_device(&priv->hbdev);
 239         if (priv->mux_ctrl)
 240                 mux_control_deselect(priv->mux_ctrl);
 241
 242         if (dev_priv->rx_chan)
 243                 dma_release_channel(dev_priv->rx_chan);
 244
 245         return ret;
 246 }
 247
 248 static const struct of_device_id am654_hbmc_dt_ids[] = {
 249         {
 250                 .compatible = "ti,am654-hbmc",
 251         },
 252         { /* end of table */ }
 253 };
 254
 255 MODULE_DEVICE_TABLE(of, am654_hbmc_dt_ids);
 256
 257 static struct platform_driver am654_hbmc_platform_driver = {
 258         .probe = am654_hbmc_probe,
 259         .remove = am654_hbmc_remove,
 260         .driver = {
 261                 .name = "hbmc-am654",
 262                 .of_match_table = am654_hbmc_dt_ids,
 263         },
 264 };
 265
 266 module_platform_driver(am654_hbmc_platform_driver);
 267
 268 MODULE_DESCRIPTION("HBMC driver for AM654 SoC");
 269 MODULE_LICENSE("GPL v2");
 270 MODULE_ALIAS("platform:hbmc-am654");
 271 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");