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>"); 284