drivers/mailbox/mailbox-xgene-slimpro.c

   1 /*
   2  * APM X-Gene SLIMpro MailBox Driver
   3  *
   4  * Copyright (c) 2015, Applied Micro Circuits Corporation
   5  * Author: Feng Kan fkan@apm.com
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  *
  20  */
  21 #include <linux/acpi.h>
  22 #include <linux/delay.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/io.h>
  25 #include <linux/mailbox_controller.h>
  26 #include <linux/module.h>
  27 #include <linux/of.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/spinlock.h>
  30
  31 #define MBOX_CON_NAME                   "slimpro-mbox"
  32 #define MBOX_REG_SET_OFFSET             0x1000
  33 #define MBOX_CNT                        8
  34 #define MBOX_STATUS_AVAIL_MASK          BIT(16)
  35 #define MBOX_STATUS_ACK_MASK            BIT(0)
  36
  37 /* Configuration and Status Registers */
  38 #define REG_DB_IN               0x00
  39 #define REG_DB_DIN0             0x04
  40 #define REG_DB_DIN1             0x08
  41 #define REG_DB_OUT              0x10
  42 #define REG_DB_DOUT0            0x14
  43 #define REG_DB_DOUT1            0x18
  44 #define REG_DB_STAT             0x20
  45 #define REG_DB_STATMASK         0x24
  46
  47 /**
  48  * X-Gene SlimPRO mailbox channel information
  49  *
  50  * @dev:        Device to which it is attached
  51  * @chan:       Pointer to mailbox communication channel
  52  * @reg:        Base address to access channel registers
  53  * @irq:        Interrupt number of the channel
  54  * @rx_msg:     Received message storage
  55  */
  56 struct slimpro_mbox_chan {
  57         struct device           *dev;
  58         struct mbox_chan        *chan;
  59         void __iomem            *reg;
  60         int                     irq;
  61         u32                     rx_msg[3];
  62 };
  63
  64 /**
  65  * X-Gene SlimPRO Mailbox controller data
  66  *
  67  * X-Gene SlimPRO Mailbox controller has 8 commnunication channels.
  68  * Each channel has a separate IRQ number assgined to it.
  69  *
  70  * @mb_ctrl:    Representation of the commnunication channel controller
  71  * @mc:         Array of SlimPRO mailbox channels of the controller
  72  * @chans:      Array of mailbox communication channels
  73  *
  74  */
  75 struct slimpro_mbox {
  76         struct mbox_controller          mb_ctrl;
  77         struct slimpro_mbox_chan        mc[MBOX_CNT];
  78         struct mbox_chan                chans[MBOX_CNT];
  79 };
  80
  81 static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
  82 {
  83         writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
  84         writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
  85         writel(msg[0], mb_chan->reg + REG_DB_OUT);
  86 }
  87
  88 static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
  89 {
  90         mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
  91         mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
  92         mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
  93 }
  94
  95 static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
  96 {
  97         u32 val = readl(mb_chan->reg + REG_DB_STAT);
  98
  99         if (val & MBOX_STATUS_ACK_MASK) {
 100                 writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
 101                 return 1;
 102         }
 103         return 0;
 104 }
 105
 106 static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
 107 {
 108         u32 val = readl(mb_chan->reg + REG_DB_STAT);
 109
 110         if (val & MBOX_STATUS_AVAIL_MASK) {
 111                 mb_chan_recv_msg(mb_chan);
 112                 writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
 113                 return 1;
 114         }
 115         return 0;
 116 }
 117
 118 static irqreturn_t slimpro_mbox_irq(int irq, void *id)
 119 {
 120         struct slimpro_mbox_chan *mb_chan = id;
 121
 122         if (mb_chan_status_ack(mb_chan))
 123                 mbox_chan_txdone(mb_chan->chan, 0);
 124
 125         if (mb_chan_status_avail(mb_chan))
 126                 mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
 127
 128         return IRQ_HANDLED;
 129 }
 130
 131 static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
 132 {
 133         struct slimpro_mbox_chan *mb_chan = chan->con_priv;
 134
 135         mb_chan_send_msg(mb_chan, msg);
 136         return 0;
 137 }
 138
 139 static int slimpro_mbox_startup(struct mbox_chan *chan)
 140 {
 141         struct slimpro_mbox_chan *mb_chan = chan->con_priv;
 142         int rc;
 143         u32 val;
 144
 145         rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
 146                               MBOX_CON_NAME, mb_chan);
 147         if (unlikely(rc)) {
 148                 dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
 149                         mb_chan->irq);
 150                 return rc;
 151         }
 152
 153         /* Enable HW interrupt */
 154         writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
 155                mb_chan->reg + REG_DB_STAT);
 156         /* Unmask doorbell status interrupt */
 157         val = readl(mb_chan->reg + REG_DB_STATMASK);
 158         val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
 159         writel(val, mb_chan->reg + REG_DB_STATMASK);
 160
 161         return 0;
 162 }
 163
 164 static void slimpro_mbox_shutdown(struct mbox_chan *chan)
 165 {
 166         struct slimpro_mbox_chan *mb_chan = chan->con_priv;
 167         u32 val;
 168
 169         /* Mask doorbell status interrupt */
 170         val = readl(mb_chan->reg + REG_DB_STATMASK);
 171         val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
 172         writel(val, mb_chan->reg + REG_DB_STATMASK);
 173
 174         devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
 175 }
 176
 177 static const struct mbox_chan_ops slimpro_mbox_ops = {
 178         .send_data = slimpro_mbox_send_data,
 179         .startup = slimpro_mbox_startup,
 180         .shutdown = slimpro_mbox_shutdown,
 181 };
 182
 183 static int slimpro_mbox_probe(struct platform_device *pdev)
 184 {
 185         struct slimpro_mbox *ctx;
 186         struct resource *regs;
 187         void __iomem *mb_base;
 188         int rc;
 189         int i;
 190
 191         ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
 192         if (!ctx)
 193                 return -ENOMEM;
 194
 195         platform_set_drvdata(pdev, ctx);
 196
 197         regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 198         mb_base = devm_ioremap_resource(&pdev->dev, regs);
 199         if (IS_ERR(mb_base))
 200                 return PTR_ERR(mb_base);
 201
 202         /* Setup mailbox links */
 203         for (i = 0; i < MBOX_CNT; i++) {
 204                 ctx->mc[i].irq = platform_get_irq(pdev, i);
 205                 if (ctx->mc[i].irq < 0) {
 206                         if (i == 0) {
 207                                 dev_err(&pdev->dev, "no available IRQ\n");
 208                                 return -EINVAL;
 209                         }
 210                         dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
 211                         break;
 212                 }
 213
 214                 ctx->mc[i].dev = &pdev->dev;
 215                 ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
 216                 ctx->mc[i].chan = &ctx->chans[i];
 217                 ctx->chans[i].con_priv = &ctx->mc[i];
 218         }
 219
 220         /* Setup mailbox controller */
 221         ctx->mb_ctrl.dev = &pdev->dev;
 222         ctx->mb_ctrl.chans = ctx->chans;
 223         ctx->mb_ctrl.txdone_irq = true;
 224         ctx->mb_ctrl.ops = &slimpro_mbox_ops;
 225         ctx->mb_ctrl.num_chans = i;
 226
 227         rc = mbox_controller_register(&ctx->mb_ctrl);
 228         if (rc) {
 229                 dev_err(&pdev->dev,
 230                         "APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
 231                 return rc;
 232         }
 233
 234         dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
 235         return 0;
 236 }
 237
 238 static int slimpro_mbox_remove(struct platform_device *pdev)
 239 {
 240         struct slimpro_mbox *smb = platform_get_drvdata(pdev);
 241
 242         mbox_controller_unregister(&smb->mb_ctrl);
 243         return 0;
 244 }
 245
 246 static const struct of_device_id slimpro_of_match[] = {
 247         {.compatible = "apm,xgene-slimpro-mbox" },
 248         { },
 249 };
 250 MODULE_DEVICE_TABLE(of, slimpro_of_match);
 251
 252 #ifdef CONFIG_ACPI
 253 static const struct acpi_device_id slimpro_acpi_ids[] = {
 254         {"APMC0D01", 0},
 255         {}
 256 };
 257 MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
 258 #endif
 259
 260 static struct platform_driver slimpro_mbox_driver = {
 261         .probe  = slimpro_mbox_probe,
 262         .remove = slimpro_mbox_remove,
 263         .driver = {
 264                 .name = "xgene-slimpro-mbox",
 265                 .of_match_table = of_match_ptr(slimpro_of_match),
 266                 .acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
 267         },
 268 };
 269
 270 static int __init slimpro_mbox_init(void)
 271 {
 272         return platform_driver_register(&slimpro_mbox_driver);
 273 }
 274
 275 static void __exit slimpro_mbox_exit(void)
 276 {
 277         platform_driver_unregister(&slimpro_mbox_driver);
 278 }
 279
 280 subsys_initcall(slimpro_mbox_init);
 281 module_exit(slimpro_mbox_exit);
 282
 283 MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
 284 MODULE_LICENSE("GPL");