drivers/mailbox/rockchip-mailbox.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2015, Fuzhou Rockchip Electronics Co., Ltd
   4  */
   5
   6 #include <linux/clk.h>
   7 #include <linux/interrupt.h>
   8 #include <linux/io.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mailbox_controller.h>
  11 #include <linux/module.h>
  12 #include <linux/of_device.h>
  13 #include <linux/platform_device.h>
  14
  15 #define MAILBOX_A2B_INTEN               0x00
  16 #define MAILBOX_A2B_STATUS              0x04
  17 #define MAILBOX_A2B_CMD(x)              (0x08 + (x) * 8)
  18 #define MAILBOX_A2B_DAT(x)              (0x0c + (x) * 8)
  19
  20 #define MAILBOX_B2A_INTEN               0x28
  21 #define MAILBOX_B2A_STATUS              0x2C
  22 #define MAILBOX_B2A_CMD(x)              (0x30 + (x) * 8)
  23 #define MAILBOX_B2A_DAT(x)              (0x34 + (x) * 8)
  24
  25 struct rockchip_mbox_msg {
  26         u32 cmd;
  27         int rx_size;
  28 };
  29
  30 struct rockchip_mbox_data {
  31         int num_chans;
  32 };
  33
  34 struct rockchip_mbox_chan {
  35         int idx;
  36         int irq;
  37         struct rockchip_mbox_msg *msg;
  38         struct rockchip_mbox *mb;
  39 };
  40
  41 struct rockchip_mbox {
  42         struct mbox_controller mbox;
  43         struct clk *pclk;
  44         void __iomem *mbox_base;
  45
  46         /* The maximum size of buf for each channel */
  47         u32 buf_size;
  48
  49         struct rockchip_mbox_chan *chans;
  50 };
  51
  52 static int rockchip_mbox_send_data(struct mbox_chan *chan, void *data)
  53 {
  54         struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
  55         struct rockchip_mbox_msg *msg = data;
  56         struct rockchip_mbox_chan *chans = mb->chans;
  57
  58         if (!msg)
  59                 return -EINVAL;
  60
  61         if (msg->rx_size > mb->buf_size) {
  62                 dev_err(mb->mbox.dev, "Transmit size over buf size(%d)\n",
  63                         mb->buf_size);
  64                 return -EINVAL;
  65         }
  66
  67         dev_dbg(mb->mbox.dev, "Chan[%d]: A2B message, cmd 0x%08x\n",
  68                 chans->idx, msg->cmd);
  69
  70         mb->chans[chans->idx].msg = msg;
  71
  72         writel_relaxed(msg->cmd, mb->mbox_base + MAILBOX_A2B_CMD(chans->idx));
  73         writel_relaxed(msg->rx_size, mb->mbox_base +
  74                        MAILBOX_A2B_DAT(chans->idx));
  75
  76         return 0;
  77 }
  78
  79 static int rockchip_mbox_startup(struct mbox_chan *chan)
  80 {
  81         struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
  82
  83         /* Enable all B2A interrupts */
  84         writel_relaxed((1 << mb->mbox.num_chans) - 1,
  85                        mb->mbox_base + MAILBOX_B2A_INTEN);
  86
  87         return 0;
  88 }
  89
  90 static void rockchip_mbox_shutdown(struct mbox_chan *chan)
  91 {
  92         struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
  93         struct rockchip_mbox_chan *chans = mb->chans;
  94
  95         /* Disable all B2A interrupts */
  96         writel_relaxed(0, mb->mbox_base + MAILBOX_B2A_INTEN);
  97
  98         mb->chans[chans->idx].msg = NULL;
  99 }
 100
 101 static const struct mbox_chan_ops rockchip_mbox_chan_ops = {
 102         .send_data      = rockchip_mbox_send_data,
 103         .startup        = rockchip_mbox_startup,
 104         .shutdown       = rockchip_mbox_shutdown,
 105 };
 106
 107 static irqreturn_t rockchip_mbox_irq(int irq, void *dev_id)
 108 {
 109         int idx;
 110         struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
 111         u32 status = readl_relaxed(mb->mbox_base + MAILBOX_B2A_STATUS);
 112
 113         for (idx = 0; idx < mb->mbox.num_chans; idx++) {
 114                 if ((status & (1 << idx)) && (irq == mb->chans[idx].irq)) {
 115                         /* Clear mbox interrupt */
 116                         writel_relaxed(1 << idx,
 117                                        mb->mbox_base + MAILBOX_B2A_STATUS);
 118                         return IRQ_WAKE_THREAD;
 119                 }
 120         }
 121
 122         return IRQ_NONE;
 123 }
 124
 125 static irqreturn_t rockchip_mbox_isr(int irq, void *dev_id)
 126 {
 127         int idx;
 128         struct rockchip_mbox_msg *msg = NULL;
 129         struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
 130
 131         for (idx = 0; idx < mb->mbox.num_chans; idx++) {
 132                 if (irq != mb->chans[idx].irq)
 133                         continue;
 134
 135                 msg = mb->chans[idx].msg;
 136                 if (!msg) {
 137                         dev_err(mb->mbox.dev,
 138                                 "Chan[%d]: B2A message is NULL\n", idx);
 139                         break; /* spurious */
 140                 }
 141
 142                 mbox_chan_received_data(&mb->mbox.chans[idx], msg);
 143                 mb->chans[idx].msg = NULL;
 144
 145                 dev_dbg(mb->mbox.dev, "Chan[%d]: B2A message, cmd 0x%08x\n",
 146                         idx, msg->cmd);
 147
 148                 break;
 149         }
 150
 151         return IRQ_HANDLED;
 152 }
 153
 154 static const struct rockchip_mbox_data rk3368_drv_data = {
 155         .num_chans = 4,
 156 };
 157
 158 static const struct of_device_id rockchip_mbox_of_match[] = {
 159         { .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data},
 160         { },
 161 };
 162 MODULE_DEVICE_TABLE(of, rockchp_mbox_of_match);
 163
 164 static int rockchip_mbox_probe(struct platform_device *pdev)
 165 {
 166         struct rockchip_mbox *mb;
 167         const struct of_device_id *match;
 168         const struct rockchip_mbox_data *drv_data;
 169         struct resource *res;
 170         int ret, irq, i;
 171
 172         if (!pdev->dev.of_node)
 173                 return -ENODEV;
 174
 175         match = of_match_node(rockchip_mbox_of_match, pdev->dev.of_node);
 176         drv_data = (const struct rockchip_mbox_data *)match->data;
 177
 178         mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL);
 179         if (!mb)
 180                 return -ENOMEM;
 181
 182         mb->chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
 183                                  sizeof(*mb->chans), GFP_KERNEL);
 184         if (!mb->chans)
 185                 return -ENOMEM;
 186
 187         mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
 188                                       sizeof(*mb->mbox.chans), GFP_KERNEL);
 189         if (!mb->mbox.chans)
 190                 return -ENOMEM;
 191
 192         platform_set_drvdata(pdev, mb);
 193
 194         mb->mbox.dev = &pdev->dev;
 195         mb->mbox.num_chans = drv_data->num_chans;
 196         mb->mbox.ops = &rockchip_mbox_chan_ops;
 197         mb->mbox.txdone_irq = true;
 198
 199         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 200         if (!res)
 201                 return -ENODEV;
 202
 203         mb->mbox_base = devm_ioremap_resource(&pdev->dev, res);
 204         if (IS_ERR(mb->mbox_base))
 205                 return PTR_ERR(mb->mbox_base);
 206
 207         /* Each channel has two buffers for A2B and B2A */
 208         mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2);
 209
 210         mb->pclk = devm_clk_get(&pdev->dev, "pclk_mailbox");
 211         if (IS_ERR(mb->pclk)) {
 212                 ret = PTR_ERR(mb->pclk);
 213                 dev_err(&pdev->dev, "failed to get pclk_mailbox clock: %d\n",
 214                         ret);
 215                 return ret;
 216         }
 217
 218         ret = clk_prepare_enable(mb->pclk);
 219         if (ret) {
 220                 dev_err(&pdev->dev, "failed to enable pclk: %d\n", ret);
 221                 return ret;
 222         }
 223
 224         for (i = 0; i < mb->mbox.num_chans; i++) {
 225                 irq = platform_get_irq(pdev, i);
 226                 if (irq < 0)
 227                         return irq;
 228
 229                 ret = devm_request_threaded_irq(&pdev->dev, irq,
 230                                                 rockchip_mbox_irq,
 231                                                 rockchip_mbox_isr, IRQF_ONESHOT,
 232                                                 dev_name(&pdev->dev), mb);
 233                 if (ret < 0)
 234                         return ret;
 235
 236                 mb->chans[i].idx = i;
 237                 mb->chans[i].irq = irq;
 238                 mb->chans[i].mb = mb;
 239                 mb->chans[i].msg = NULL;
 240         }
 241
 242         ret = devm_mbox_controller_register(&pdev->dev, &mb->mbox);
 243         if (ret < 0)
 244                 dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret);
 245
 246         return ret;
 247 }
 248
 249 static struct platform_driver rockchip_mbox_driver = {
 250         .probe  = rockchip_mbox_probe,
 251         .driver = {
 252                 .name = "rockchip-mailbox",
 253                 .of_match_table = of_match_ptr(rockchip_mbox_of_match),
 254         },
 255 };
 256
 257 module_platform_driver(rockchip_mbox_driver);
 258
 259 MODULE_LICENSE("GPL v2");
 260 MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU");
 261 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
 262 MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>");