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 void 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; 236 237 hyperbus_unregister_device(&priv->hbdev); 238 239 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 } 245 246 static const struct of_device_id am654_hbmc_dt_ids[] = { 247 { 248 .compatible = "ti,am654-hbmc", 249 }, 250 { /* end of table */ } 251 }; 252 253 MODULE_DEVICE_TABLE(of, am654_hbmc_dt_ids); 254 255 static struct platform_driver am654_hbmc_platform_driver = { 256 .probe = am654_hbmc_probe, 257 .remove_new = am654_hbmc_remove, 258 .driver = { 259 .name = "hbmc-am654", 260 .of_match_table = am654_hbmc_dt_ids, 261 }, 262 }; 263 264 module_platform_driver(am654_hbmc_platform_driver); 265 266 MODULE_DESCRIPTION("HBMC driver for AM654 SoC"); 267 MODULE_LICENSE("GPL v2"); 268 MODULE_ALIAS("platform:hbmc-am654"); 269 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>"); 270