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 34 #include <linux/can/dev.h> 35 36 #include "c_can.h" 37 38 /* 39 * 16-bit c_can registers can be arranged differently in the memory 40 * architecture of different implementations. For example: 16-bit 41 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc. 42 * Handle the same by providing a common read/write interface. 43 */ 44 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv, 45 enum reg index) 46 { 47 return readw(priv->base + priv->regs[index]); 48 } 49 50 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv, 51 enum reg index, u16 val) 52 { 53 writew(val, priv->base + priv->regs[index]); 54 } 55 56 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv, 57 enum reg index) 58 { 59 return readw(priv->base + 2 * priv->regs[index]); 60 } 61 62 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv, 63 enum reg index, u16 val) 64 { 65 writew(val, priv->base + 2 * priv->regs[index]); 66 } 67 68 static int __devinit c_can_plat_probe(struct platform_device *pdev) 69 { 70 int ret; 71 void __iomem *addr; 72 struct net_device *dev; 73 struct c_can_priv *priv; 74 const struct platform_device_id *id; 75 struct resource *mem; 76 int irq; 77 struct clk *clk; 78 79 /* get the appropriate clk */ 80 clk = clk_get(&pdev->dev, NULL); 81 if (IS_ERR(clk)) { 82 dev_err(&pdev->dev, "no clock defined\n"); 83 ret = -ENODEV; 84 goto exit; 85 } 86 87 /* get the platform data */ 88 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 89 irq = platform_get_irq(pdev, 0); 90 if (!mem || irq <= 0) { 91 ret = -ENODEV; 92 goto exit_free_clk; 93 } 94 95 if (!request_mem_region(mem->start, resource_size(mem), 96 KBUILD_MODNAME)) { 97 dev_err(&pdev->dev, "resource unavailable\n"); 98 ret = -ENODEV; 99 goto exit_free_clk; 100 } 101 102 addr = ioremap(mem->start, resource_size(mem)); 103 if (!addr) { 104 dev_err(&pdev->dev, "failed to map can port\n"); 105 ret = -ENOMEM; 106 goto exit_release_mem; 107 } 108 109 /* allocate the c_can device */ 110 dev = alloc_c_can_dev(); 111 if (!dev) { 112 ret = -ENOMEM; 113 goto exit_iounmap; 114 } 115 116 priv = netdev_priv(dev); 117 id = platform_get_device_id(pdev); 118 switch (id->driver_data) { 119 case C_CAN_DEVTYPE: 120 priv->regs = reg_map_c_can; 121 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) { 122 case IORESOURCE_MEM_32BIT: 123 priv->read_reg = c_can_plat_read_reg_aligned_to_32bit; 124 priv->write_reg = c_can_plat_write_reg_aligned_to_32bit; 125 break; 126 case IORESOURCE_MEM_16BIT: 127 default: 128 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit; 129 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit; 130 break; 131 } 132 break; 133 case D_CAN_DEVTYPE: 134 priv->regs = reg_map_d_can; 135 priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES; 136 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit; 137 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit; 138 break; 139 default: 140 ret = -EINVAL; 141 goto exit_free_device; 142 } 143 144 dev->irq = irq; 145 priv->base = addr; 146 priv->can.clock.freq = clk_get_rate(clk); 147 priv->priv = clk; 148 149 platform_set_drvdata(pdev, dev); 150 SET_NETDEV_DEV(dev, &pdev->dev); 151 152 ret = register_c_can_dev(dev); 153 if (ret) { 154 dev_err(&pdev->dev, "registering %s failed (err=%d)\n", 155 KBUILD_MODNAME, ret); 156 goto exit_free_device; 157 } 158 159 dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n", 160 KBUILD_MODNAME, priv->base, dev->irq); 161 return 0; 162 163 exit_free_device: 164 platform_set_drvdata(pdev, NULL); 165 free_c_can_dev(dev); 166 exit_iounmap: 167 iounmap(addr); 168 exit_release_mem: 169 release_mem_region(mem->start, resource_size(mem)); 170 exit_free_clk: 171 clk_put(clk); 172 exit: 173 dev_err(&pdev->dev, "probe failed\n"); 174 175 return ret; 176 } 177 178 static int __devexit c_can_plat_remove(struct platform_device *pdev) 179 { 180 struct net_device *dev = platform_get_drvdata(pdev); 181 struct c_can_priv *priv = netdev_priv(dev); 182 struct resource *mem; 183 184 unregister_c_can_dev(dev); 185 platform_set_drvdata(pdev, NULL); 186 187 free_c_can_dev(dev); 188 iounmap(priv->base); 189 190 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 191 release_mem_region(mem->start, resource_size(mem)); 192 193 clk_put(priv->priv); 194 195 return 0; 196 } 197 198 static const struct platform_device_id c_can_id_table[] = { 199 { 200 .name = KBUILD_MODNAME, 201 .driver_data = C_CAN_DEVTYPE, 202 }, { 203 .name = "c_can", 204 .driver_data = C_CAN_DEVTYPE, 205 }, { 206 .name = "d_can", 207 .driver_data = D_CAN_DEVTYPE, 208 }, { 209 } 210 }; 211 212 static struct platform_driver c_can_plat_driver = { 213 .driver = { 214 .name = KBUILD_MODNAME, 215 .owner = THIS_MODULE, 216 }, 217 .probe = c_can_plat_probe, 218 .remove = __devexit_p(c_can_plat_remove), 219 .id_table = c_can_id_table, 220 }; 221 222 module_platform_driver(c_can_plat_driver); 223 224 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>"); 225 MODULE_LICENSE("GPL v2"); 226 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller"); 227