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/of.h> 12 #include <linux/module.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, rockchip_mbox_of_match); 163 164 static int rockchip_mbox_probe(struct platform_device *pdev) 165 { 166 struct rockchip_mbox *mb; 167 const struct rockchip_mbox_data *drv_data; 168 struct resource *res; 169 int ret, irq, i; 170 171 if (!pdev->dev.of_node) 172 return -ENODEV; 173 174 drv_data = (const struct rockchip_mbox_data *) device_get_match_data(&pdev->dev); 175 176 mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL); 177 if (!mb) 178 return -ENOMEM; 179 180 mb->chans = devm_kcalloc(&pdev->dev, drv_data->num_chans, 181 sizeof(*mb->chans), GFP_KERNEL); 182 if (!mb->chans) 183 return -ENOMEM; 184 185 mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans, 186 sizeof(*mb->mbox.chans), GFP_KERNEL); 187 if (!mb->mbox.chans) 188 return -ENOMEM; 189 190 platform_set_drvdata(pdev, mb); 191 192 mb->mbox.dev = &pdev->dev; 193 mb->mbox.num_chans = drv_data->num_chans; 194 mb->mbox.ops = &rockchip_mbox_chan_ops; 195 mb->mbox.txdone_irq = true; 196 197 mb->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 198 if (IS_ERR(mb->mbox_base)) 199 return PTR_ERR(mb->mbox_base); 200 201 /* Each channel has two buffers for A2B and B2A */ 202 mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2); 203 204 mb->pclk = devm_clk_get(&pdev->dev, "pclk_mailbox"); 205 if (IS_ERR(mb->pclk)) { 206 ret = PTR_ERR(mb->pclk); 207 dev_err(&pdev->dev, "failed to get pclk_mailbox clock: %d\n", 208 ret); 209 return ret; 210 } 211 212 ret = clk_prepare_enable(mb->pclk); 213 if (ret) { 214 dev_err(&pdev->dev, "failed to enable pclk: %d\n", ret); 215 return ret; 216 } 217 218 for (i = 0; i < mb->mbox.num_chans; i++) { 219 irq = platform_get_irq(pdev, i); 220 if (irq < 0) 221 return irq; 222 223 ret = devm_request_threaded_irq(&pdev->dev, irq, 224 rockchip_mbox_irq, 225 rockchip_mbox_isr, IRQF_ONESHOT, 226 dev_name(&pdev->dev), mb); 227 if (ret < 0) 228 return ret; 229 230 mb->chans[i].idx = i; 231 mb->chans[i].irq = irq; 232 mb->chans[i].mb = mb; 233 mb->chans[i].msg = NULL; 234 } 235 236 ret = devm_mbox_controller_register(&pdev->dev, &mb->mbox); 237 if (ret < 0) 238 dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret); 239 240 return ret; 241 } 242 243 static struct platform_driver rockchip_mbox_driver = { 244 .probe = rockchip_mbox_probe, 245 .driver = { 246 .name = "rockchip-mailbox", 247 .of_match_table = rockchip_mbox_of_match, 248 }, 249 }; 250 251 module_platform_driver(rockchip_mbox_driver); 252 253 MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU"); 254 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>"); 255 MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>"); 256