1 /* 2 * Platform CAN bus driver for Bosch C_CAN controller 3 * 4 * Copyright (C) 2010 ST Microelectronics 5 * Bhupesh Sharma <bhupesh.sharma@st.com> 6 * 7 * Borrowed heavily from the C_CAN driver originally written by: 8 * Copyright (C) 2007 9 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de> 10 * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch> 11 * 12 * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B. 13 * Bosch C_CAN user manual can be obtained from: 14 * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/ 15 * users_manual_c_can.pdf 16 * 17 * This file is licensed under the terms of the GNU General Public 18 * License version 2. This program is licensed "as is" without any 19 * warranty of any kind, whether express or implied. 20 */ 21 22 #include <linux/kernel.h> 23 #include <linux/module.h> 24 #include <linux/interrupt.h> 25 #include <linux/delay.h> 26 #include <linux/netdevice.h> 27 #include <linux/if_arp.h> 28 #include <linux/if_ether.h> 29 #include <linux/list.h> 30 #include <linux/io.h> 31 #include <linux/platform_device.h> 32 #include <linux/clk.h> 33 #include <linux/of.h> 34 #include <linux/of_device.h> 35 #include <linux/pinctrl/consumer.h> 36 37 #include <linux/can/dev.h> 38 39 #include "c_can.h" 40 41 /* 42 * 16-bit c_can registers can be arranged differently in the memory 43 * architecture of different implementations. For example: 16-bit 44 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc. 45 * Handle the same by providing a common read/write interface. 46 */ 47 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv, 48 enum reg index) 49 { 50 return readw(priv->base + priv->regs[index]); 51 } 52 53 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv, 54 enum reg index, u16 val) 55 { 56 writew(val, priv->base + priv->regs[index]); 57 } 58 59 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv, 60 enum reg index) 61 { 62 return readw(priv->base + 2 * priv->regs[index]); 63 } 64 65 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv, 66 enum reg index, u16 val) 67 { 68 writew(val, priv->base + 2 * priv->regs[index]); 69 } 70 71 static struct platform_device_id c_can_id_table[] = { 72 [BOSCH_C_CAN_PLATFORM] = { 73 .name = KBUILD_MODNAME, 74 .driver_data = BOSCH_C_CAN, 75 }, 76 [BOSCH_C_CAN] = { 77 .name = "c_can", 78 .driver_data = BOSCH_C_CAN, 79 }, 80 [BOSCH_D_CAN] = { 81 .name = "d_can", 82 .driver_data = BOSCH_D_CAN, 83 }, { 84 } 85 }; 86 87 static const struct of_device_id c_can_of_table[] = { 88 { .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] }, 89 { .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] }, 90 { /* sentinel */ }, 91 }; 92 93 static int __devinit c_can_plat_probe(struct platform_device *pdev) 94 { 95 int ret; 96 void __iomem *addr; 97 struct net_device *dev; 98 struct c_can_priv *priv; 99 const struct of_device_id *match; 100 const struct platform_device_id *id; 101 struct pinctrl *pinctrl; 102 struct resource *mem; 103 int irq; 104 struct clk *clk; 105 106 if (pdev->dev.of_node) { 107 match = of_match_device(c_can_of_table, &pdev->dev); 108 if (!match) { 109 dev_err(&pdev->dev, "Failed to find matching dt id\n"); 110 ret = -EINVAL; 111 goto exit; 112 } 113 id = match->data; 114 } else { 115 id = platform_get_device_id(pdev); 116 } 117 118 pinctrl = devm_pinctrl_get_select_default(&pdev->dev); 119 if (IS_ERR(pinctrl)) 120 dev_warn(&pdev->dev, 121 "failed to configure pins from driver\n"); 122 123 /* get the appropriate clk */ 124 clk = clk_get(&pdev->dev, NULL); 125 if (IS_ERR(clk)) { 126 dev_err(&pdev->dev, "no clock defined\n"); 127 ret = -ENODEV; 128 goto exit; 129 } 130 131 /* get the platform data */ 132 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 133 irq = platform_get_irq(pdev, 0); 134 if (!mem || irq <= 0) { 135 ret = -ENODEV; 136 goto exit_free_clk; 137 } 138 139 if (!request_mem_region(mem->start, resource_size(mem), 140 KBUILD_MODNAME)) { 141 dev_err(&pdev->dev, "resource unavailable\n"); 142 ret = -ENODEV; 143 goto exit_free_clk; 144 } 145 146 addr = ioremap(mem->start, resource_size(mem)); 147 if (!addr) { 148 dev_err(&pdev->dev, "failed to map can port\n"); 149 ret = -ENOMEM; 150 goto exit_release_mem; 151 } 152 153 /* allocate the c_can device */ 154 dev = alloc_c_can_dev(); 155 if (!dev) { 156 ret = -ENOMEM; 157 goto exit_iounmap; 158 } 159 160 priv = netdev_priv(dev); 161 switch (id->driver_data) { 162 case BOSCH_C_CAN: 163 priv->regs = reg_map_c_can; 164 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) { 165 case IORESOURCE_MEM_32BIT: 166 priv->read_reg = c_can_plat_read_reg_aligned_to_32bit; 167 priv->write_reg = c_can_plat_write_reg_aligned_to_32bit; 168 break; 169 case IORESOURCE_MEM_16BIT: 170 default: 171 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit; 172 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit; 173 break; 174 } 175 break; 176 case BOSCH_D_CAN: 177 priv->regs = reg_map_d_can; 178 priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES; 179 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit; 180 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit; 181 break; 182 default: 183 ret = -EINVAL; 184 goto exit_free_device; 185 } 186 187 dev->irq = irq; 188 priv->base = addr; 189 priv->device = &pdev->dev; 190 priv->can.clock.freq = clk_get_rate(clk); 191 priv->priv = clk; 192 priv->type = id->driver_data; 193 194 platform_set_drvdata(pdev, dev); 195 SET_NETDEV_DEV(dev, &pdev->dev); 196 197 ret = register_c_can_dev(dev); 198 if (ret) { 199 dev_err(&pdev->dev, "registering %s failed (err=%d)\n", 200 KBUILD_MODNAME, ret); 201 goto exit_free_device; 202 } 203 204 dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n", 205 KBUILD_MODNAME, priv->base, dev->irq); 206 return 0; 207 208 exit_free_device: 209 platform_set_drvdata(pdev, NULL); 210 free_c_can_dev(dev); 211 exit_iounmap: 212 iounmap(addr); 213 exit_release_mem: 214 release_mem_region(mem->start, resource_size(mem)); 215 exit_free_clk: 216 clk_put(clk); 217 exit: 218 dev_err(&pdev->dev, "probe failed\n"); 219 220 return ret; 221 } 222 223 static int __devexit c_can_plat_remove(struct platform_device *pdev) 224 { 225 struct net_device *dev = platform_get_drvdata(pdev); 226 struct c_can_priv *priv = netdev_priv(dev); 227 struct resource *mem; 228 229 unregister_c_can_dev(dev); 230 platform_set_drvdata(pdev, NULL); 231 232 free_c_can_dev(dev); 233 iounmap(priv->base); 234 235 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 236 release_mem_region(mem->start, resource_size(mem)); 237 238 clk_put(priv->priv); 239 240 return 0; 241 } 242 243 #ifdef CONFIG_PM 244 static int c_can_suspend(struct platform_device *pdev, pm_message_t state) 245 { 246 int ret; 247 struct net_device *ndev = platform_get_drvdata(pdev); 248 struct c_can_priv *priv = netdev_priv(ndev); 249 250 if (priv->type != BOSCH_D_CAN) { 251 dev_warn(&pdev->dev, "Not supported\n"); 252 return 0; 253 } 254 255 if (netif_running(ndev)) { 256 netif_stop_queue(ndev); 257 netif_device_detach(ndev); 258 } 259 260 ret = c_can_power_down(ndev); 261 if (ret) { 262 netdev_err(ndev, "failed to enter power down mode\n"); 263 return ret; 264 } 265 266 priv->can.state = CAN_STATE_SLEEPING; 267 268 return 0; 269 } 270 271 static int c_can_resume(struct platform_device *pdev) 272 { 273 int ret; 274 struct net_device *ndev = platform_get_drvdata(pdev); 275 struct c_can_priv *priv = netdev_priv(ndev); 276 277 if (priv->type != BOSCH_D_CAN) { 278 dev_warn(&pdev->dev, "Not supported\n"); 279 return 0; 280 } 281 282 ret = c_can_power_up(ndev); 283 if (ret) { 284 netdev_err(ndev, "Still in power down mode\n"); 285 return ret; 286 } 287 288 priv->can.state = CAN_STATE_ERROR_ACTIVE; 289 290 if (netif_running(ndev)) { 291 netif_device_attach(ndev); 292 netif_start_queue(ndev); 293 } 294 295 return 0; 296 } 297 #else 298 #define c_can_suspend NULL 299 #define c_can_resume NULL 300 #endif 301 302 static struct platform_driver c_can_plat_driver = { 303 .driver = { 304 .name = KBUILD_MODNAME, 305 .owner = THIS_MODULE, 306 .of_match_table = of_match_ptr(c_can_of_table), 307 }, 308 .probe = c_can_plat_probe, 309 .remove = __devexit_p(c_can_plat_remove), 310 .suspend = c_can_suspend, 311 .resume = c_can_resume, 312 .id_table = c_can_id_table, 313 }; 314 315 module_platform_driver(c_can_plat_driver); 316 317 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>"); 318 MODULE_LICENSE("GPL v2"); 319 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller"); 320