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 void __iomem *mbox_base; 44 45 /* The maximum size of buf for each channel */ 46 u32 buf_size; 47 48 struct rockchip_mbox_chan chans[]; 49 }; 50 51 static int rockchip_mbox_send_data(struct mbox_chan *chan, void *data) 52 { 53 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev); 54 struct rockchip_mbox_msg *msg = data; 55 struct rockchip_mbox_chan *chans = mb->chans; 56 57 if (!msg) 58 return -EINVAL; 59 60 if (msg->rx_size > mb->buf_size) { 61 dev_err(mb->mbox.dev, "Transmit size over buf size(%d)\n", 62 mb->buf_size); 63 return -EINVAL; 64 } 65 66 dev_dbg(mb->mbox.dev, "Chan[%d]: A2B message, cmd 0x%08x\n", 67 chans->idx, msg->cmd); 68 69 mb->chans[chans->idx].msg = msg; 70 71 writel_relaxed(msg->cmd, mb->mbox_base + MAILBOX_A2B_CMD(chans->idx)); 72 writel_relaxed(msg->rx_size, mb->mbox_base + 73 MAILBOX_A2B_DAT(chans->idx)); 74 75 return 0; 76 } 77 78 static int rockchip_mbox_startup(struct mbox_chan *chan) 79 { 80 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev); 81 82 /* Enable all B2A interrupts */ 83 writel_relaxed((1 << mb->mbox.num_chans) - 1, 84 mb->mbox_base + MAILBOX_B2A_INTEN); 85 86 return 0; 87 } 88 89 static void rockchip_mbox_shutdown(struct mbox_chan *chan) 90 { 91 struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev); 92 struct rockchip_mbox_chan *chans = mb->chans; 93 94 /* Disable all B2A interrupts */ 95 writel_relaxed(0, mb->mbox_base + MAILBOX_B2A_INTEN); 96 97 mb->chans[chans->idx].msg = NULL; 98 } 99 100 static const struct mbox_chan_ops rockchip_mbox_chan_ops = { 101 .send_data = rockchip_mbox_send_data, 102 .startup = rockchip_mbox_startup, 103 .shutdown = rockchip_mbox_shutdown, 104 }; 105 106 static irqreturn_t rockchip_mbox_irq(int irq, void *dev_id) 107 { 108 int idx; 109 struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id; 110 u32 status = readl_relaxed(mb->mbox_base + MAILBOX_B2A_STATUS); 111 112 for (idx = 0; idx < mb->mbox.num_chans; idx++) { 113 if ((status & (1 << idx)) && (irq == mb->chans[idx].irq)) { 114 /* Clear mbox interrupt */ 115 writel_relaxed(1 << idx, 116 mb->mbox_base + MAILBOX_B2A_STATUS); 117 return IRQ_WAKE_THREAD; 118 } 119 } 120 121 return IRQ_NONE; 122 } 123 124 static irqreturn_t rockchip_mbox_isr(int irq, void *dev_id) 125 { 126 int idx; 127 struct rockchip_mbox_msg *msg = NULL; 128 struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id; 129 130 for (idx = 0; idx < mb->mbox.num_chans; idx++) { 131 if (irq != mb->chans[idx].irq) 132 continue; 133 134 msg = mb->chans[idx].msg; 135 if (!msg) { 136 dev_err(mb->mbox.dev, 137 "Chan[%d]: B2A message is NULL\n", idx); 138 break; /* spurious */ 139 } 140 141 mbox_chan_received_data(&mb->mbox.chans[idx], msg); 142 mb->chans[idx].msg = NULL; 143 144 dev_dbg(mb->mbox.dev, "Chan[%d]: B2A message, cmd 0x%08x\n", 145 idx, msg->cmd); 146 147 break; 148 } 149 150 return IRQ_HANDLED; 151 } 152 153 static const struct rockchip_mbox_data rk3368_drv_data = { 154 .num_chans = 4, 155 }; 156 157 static const struct of_device_id rockchip_mbox_of_match[] = { 158 { .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data}, 159 { }, 160 }; 161 MODULE_DEVICE_TABLE(of, rockchip_mbox_of_match); 162 163 static int rockchip_mbox_probe(struct platform_device *pdev) 164 { 165 struct rockchip_mbox *mb; 166 const struct rockchip_mbox_data *drv_data; 167 struct resource *res; 168 struct clk *pclk; 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, struct_size(mb, chans, drv_data->num_chans), GFP_KERNEL); 177 if (!mb) 178 return -ENOMEM; 179 180 mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans, 181 sizeof(*mb->mbox.chans), GFP_KERNEL); 182 if (!mb->mbox.chans) 183 return -ENOMEM; 184 185 platform_set_drvdata(pdev, mb); 186 187 mb->mbox.dev = &pdev->dev; 188 mb->mbox.num_chans = drv_data->num_chans; 189 mb->mbox.ops = &rockchip_mbox_chan_ops; 190 mb->mbox.txdone_irq = true; 191 192 mb->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 193 if (IS_ERR(mb->mbox_base)) 194 return PTR_ERR(mb->mbox_base); 195 196 /* Each channel has two buffers for A2B and B2A */ 197 mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2); 198 199 pclk = devm_clk_get_enabled(&pdev->dev, "pclk_mailbox"); 200 if (IS_ERR(pclk)) 201 return dev_err_probe(&pdev->dev, PTR_ERR(pclk), 202 "failed to get and enable pclk_mailbox clock\n"); 203 204 for (i = 0; i < mb->mbox.num_chans; i++) { 205 irq = platform_get_irq(pdev, i); 206 if (irq < 0) 207 return irq; 208 209 ret = devm_request_threaded_irq(&pdev->dev, irq, 210 rockchip_mbox_irq, 211 rockchip_mbox_isr, IRQF_ONESHOT, 212 dev_name(&pdev->dev), mb); 213 if (ret < 0) 214 return ret; 215 216 mb->chans[i].idx = i; 217 mb->chans[i].irq = irq; 218 mb->chans[i].mb = mb; 219 mb->chans[i].msg = NULL; 220 } 221 222 ret = devm_mbox_controller_register(&pdev->dev, &mb->mbox); 223 if (ret < 0) 224 dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret); 225 226 return ret; 227 } 228 229 static struct platform_driver rockchip_mbox_driver = { 230 .probe = rockchip_mbox_probe, 231 .driver = { 232 .name = "rockchip-mailbox", 233 .of_match_table = rockchip_mbox_of_match, 234 }, 235 }; 236 237 module_platform_driver(rockchip_mbox_driver); 238 239 MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU"); 240 MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>"); 241 MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>"); 242