drivers/mailbox/rockchip-mailbox.c

   1 /*
   2  * Copyright (c) 2015, Fuzhou Rockchip Electronics Co., Ltd
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  */
  13
  14 #include <linux/clk.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/mailbox_controller.h>
  19 #include <linux/module.h>
  20 #include <linux/of_device.h>
  21 #include <linux/platform_device.h>
  22
  23 #define MAILBOX_A2B_INTEN               0x00
  24 #define MAILBOX_A2B_STATUS              0x04
  25 #define MAILBOX_A2B_CMD(x)              (0x08 + (x) * 8)
  26 #define MAILBOX_A2B_DAT(x)              (0x0c + (x) * 8)
  27
  28 #define MAILBOX_B2A_INTEN               0x28
  29 #define MAILBOX_B2A_STATUS              0x2C
  30 #define MAILBOX_B2A_CMD(x)              (0x30 + (x) * 8)
  31 #define MAILBOX_B2A_DAT(x)              (0x34 + (x) * 8)
  32
  33 struct rockchip_mbox_msg {
  34         u32 cmd;
  35         int rx_size;
  36 };
  37
  38 struct rockchip_mbox_data {
  39         int num_chans;
  40 };
  41
  42 struct rockchip_mbox_chan {
  43         int idx;
  44         int irq;
  45         struct rockchip_mbox_msg *msg;
  46         struct rockchip_mbox *mb;
  47 };
  48
  49 struct rockchip_mbox {
  50         struct mbox_controller mbox;
  51         struct clk *pclk;
  52         void __iomem *mbox_base;
  53
  54         /* The maximum size of buf for each channel */
  55         u32 buf_size;
  56
  57         struct rockchip_mbox_chan *chans;
  58 };
  59
  60 static int rockchip_mbox_send_data(struct mbox_chan *chan, void *data)
  61 {
  62         struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
  63         struct rockchip_mbox_msg *msg = data;
  64         struct rockchip_mbox_chan *chans = mb->chans;
  65
  66         if (!msg)
  67                 return -EINVAL;
  68
  69         if (msg->rx_size > mb->buf_size) {
  70                 dev_err(mb->mbox.dev, "Transmit size over buf size(%d)\n",
  71                         mb->buf_size);
  72                 return -EINVAL;
  73         }
  74
  75         dev_dbg(mb->mbox.dev, "Chan[%d]: A2B message, cmd 0x%08x\n",
  76                 chans->idx, msg->cmd);
  77
  78         mb->chans[chans->idx].msg = msg;
  79
  80         writel_relaxed(msg->cmd, mb->mbox_base + MAILBOX_A2B_CMD(chans->idx));
  81         writel_relaxed(msg->rx_size, mb->mbox_base +
  82                        MAILBOX_A2B_DAT(chans->idx));
  83
  84         return 0;
  85 }
  86
  87 static int rockchip_mbox_startup(struct mbox_chan *chan)
  88 {
  89         struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
  90
  91         /* Enable all B2A interrupts */
  92         writel_relaxed((1 << mb->mbox.num_chans) - 1,
  93                        mb->mbox_base + MAILBOX_B2A_INTEN);
  94
  95         return 0;
  96 }
  97
  98 static void rockchip_mbox_shutdown(struct mbox_chan *chan)
  99 {
 100         struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
 101         struct rockchip_mbox_chan *chans = mb->chans;
 102
 103         /* Disable all B2A interrupts */
 104         writel_relaxed(0, mb->mbox_base + MAILBOX_B2A_INTEN);
 105
 106         mb->chans[chans->idx].msg = NULL;
 107 }
 108
 109 static const struct mbox_chan_ops rockchip_mbox_chan_ops = {
 110         .send_data      = rockchip_mbox_send_data,
 111         .startup        = rockchip_mbox_startup,
 112         .shutdown       = rockchip_mbox_shutdown,
 113 };
 114
 115 static irqreturn_t rockchip_mbox_irq(int irq, void *dev_id)
 116 {
 117         int idx;
 118         struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
 119         u32 status = readl_relaxed(mb->mbox_base + MAILBOX_B2A_STATUS);
 120
 121         for (idx = 0; idx < mb->mbox.num_chans; idx++) {
 122                 if ((status & (1 << idx)) && (irq == mb->chans[idx].irq)) {
 123                         /* Clear mbox interrupt */
 124                         writel_relaxed(1 << idx,
 125                                        mb->mbox_base + MAILBOX_B2A_STATUS);
 126                         return IRQ_WAKE_THREAD;
 127                 }
 128         }
 129
 130         return IRQ_NONE;
 131 }
 132
 133 static irqreturn_t rockchip_mbox_isr(int irq, void *dev_id)
 134 {
 135         int idx;
 136         struct rockchip_mbox_msg *msg = NULL;
 137         struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
 138
 139         for (idx = 0; idx < mb->mbox.num_chans; idx++) {
 140                 if (irq != mb->chans[idx].irq)
 141                         continue;
 142
 143                 msg = mb->chans[idx].msg;
 144                 if (!msg) {
 145                         dev_err(mb->mbox.dev,
 146                                 "Chan[%d]: B2A message is NULL\n", idx);
 147                         break; /* spurious */
 148                 }
 149
 150                 mbox_chan_received_data(&mb->mbox.chans[idx], msg);
 151                 mb->chans[idx].msg = NULL;
 152
 153                 dev_dbg(mb->mbox.dev, "Chan[%d]: B2A message, cmd 0x%08x\n",
 154                         idx, msg->cmd);
 155
 156                 break;
 157         }
 158
 159         return IRQ_HANDLED;
 160 }
 161
 162 static const struct rockchip_mbox_data rk3368_drv_data = {
 163         .num_chans = 4,
 164 };
 165
 166 static const struct of_device_id rockchip_mbox_of_match[] = {
 167         { .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data},
 168         { },
 169 };
 170 MODULE_DEVICE_TABLE(of, rockchp_mbox_of_match);
 171
 172 static int rockchip_mbox_probe(struct platform_device *pdev)
 173 {
 174         struct rockchip_mbox *mb;
 175         const struct of_device_id *match;
 176         const struct rockchip_mbox_data *drv_data;
 177         struct resource *res;
 178         int ret, irq, i;
 179
 180         if (!pdev->dev.of_node)
 181                 return -ENODEV;
 182
 183         match = of_match_node(rockchip_mbox_of_match, pdev->dev.of_node);
 184         drv_data = (const struct rockchip_mbox_data *)match->data;
 185
 186         mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL);
 187         if (!mb)
 188                 return -ENOMEM;
 189
 190         mb->chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
 191                                  sizeof(*mb->chans), GFP_KERNEL);
 192         if (!mb->chans)
 193                 return -ENOMEM;
 194
 195         mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
 196                                       sizeof(*mb->mbox.chans), GFP_KERNEL);
 197         if (!mb->mbox.chans)
 198                 return -ENOMEM;
 199
 200         platform_set_drvdata(pdev, mb);
 201
 202         mb->mbox.dev = &pdev->dev;
 203         mb->mbox.num_chans = drv_data->num_chans;
 204         mb->mbox.ops = &rockchip_mbox_chan_ops;
 205         mb->mbox.txdone_irq = true;
 206
 207         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 208         if (!res)
 209                 return -ENODEV;
 210
 211         mb->mbox_base = devm_ioremap_resource(&pdev->dev, res);
 212         if (IS_ERR(mb->mbox_base))
 213                 return PTR_ERR(mb->mbox_base);
 214
 215         /* Each channel has two buffers for A2B and B2A */
 216         mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2);
 217
 218         mb->pclk = devm_clk_get(&pdev->dev, "pclk_mailbox");
 219         if (IS_ERR(mb->pclk)) {
 220                 ret = PTR_ERR(mb->pclk);
 221                 dev_err(&pdev->dev, "failed to get pclk_mailbox clock: %d\n",
 222                         ret);
 223                 return ret;
 224         }
 225
 226         ret = clk_prepare_enable(mb->pclk);
 227         if (ret) {
 228                 dev_err(&pdev->dev, "failed to enable pclk: %d\n", ret);
 229                 return ret;
 230         }
 231
 232         for (i = 0; i < mb->mbox.num_chans; i++) {
 233                 irq = platform_get_irq(pdev, i);
 234                 if (irq < 0)
 235                         return irq;
 236
 237                 ret = devm_request_threaded_irq(&pdev->dev, irq,
 238                                                 rockchip_mbox_irq,
 239                                                 rockchip_mbox_isr, IRQF_ONESHOT,
 240                                                 dev_name(&pdev->dev), mb);
 241                 if (ret < 0)
 242                         return ret;
 243
 244                 mb->chans[i].idx = i;
 245                 mb->chans[i].irq = irq;
 246                 mb->chans[i].mb = mb;
 247                 mb->chans[i].msg = NULL;
 248         }
 249
 250         ret = mbox_controller_register(&mb->mbox);
 251         if (ret < 0)
 252                 dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret);
 253
 254         return ret;
 255 }
 256
 257 static int rockchip_mbox_remove(struct platform_device *pdev)
 258 {
 259         struct rockchip_mbox *mb = platform_get_drvdata(pdev);
 260
 261         if (!mb)
 262                 return -EINVAL;
 263
 264         mbox_controller_unregister(&mb->mbox);
 265
 266         return 0;
 267 }
 268
 269 static struct platform_driver rockchip_mbox_driver = {
 270         .probe  = rockchip_mbox_probe,
 271         .remove = rockchip_mbox_remove,
 272         .driver = {
 273                 .name = "rockchip-mailbox",
 274                 .of_match_table = of_match_ptr(rockchip_mbox_of_match),
 275         },
 276 };
 277
 278 module_platform_driver(rockchip_mbox_driver);
 279
 280 MODULE_LICENSE("GPL v2");
 281 MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU");
 282 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
 283 MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>");