c_can_platform.c revision 33f8100977693fa09c2a32b1ca6dbf4d6eabdd0c
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 */ 44static 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 50static 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 56static 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 62static 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 68static 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 struct resource *mem; 75 int irq; 76#ifdef CONFIG_HAVE_CLK 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#endif 87 88 /* get the platform data */ 89 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 90 irq = platform_get_irq(pdev, 0); 91 if (!mem || irq <= 0) { 92 ret = -ENODEV; 93 goto exit_free_clk; 94 } 95 96 if (!request_mem_region(mem->start, resource_size(mem), 97 KBUILD_MODNAME)) { 98 dev_err(&pdev->dev, "resource unavailable\n"); 99 ret = -ENODEV; 100 goto exit_free_clk; 101 } 102 103 addr = ioremap(mem->start, resource_size(mem)); 104 if (!addr) { 105 dev_err(&pdev->dev, "failed to map can port\n"); 106 ret = -ENOMEM; 107 goto exit_release_mem; 108 } 109 110 /* allocate the c_can device */ 111 dev = alloc_c_can_dev(); 112 if (!dev) { 113 ret = -ENOMEM; 114 goto exit_iounmap; 115 } 116 117 priv = netdev_priv(dev); 118 priv->regs = reg_map_c_can; 119 120 dev->irq = irq; 121 priv->base = addr; 122#ifdef CONFIG_HAVE_CLK 123 priv->can.clock.freq = clk_get_rate(clk); 124 priv->priv = clk; 125#endif 126 127 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) { 128 case IORESOURCE_MEM_32BIT: 129 priv->read_reg = c_can_plat_read_reg_aligned_to_32bit; 130 priv->write_reg = c_can_plat_write_reg_aligned_to_32bit; 131 break; 132 case IORESOURCE_MEM_16BIT: 133 default: 134 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit; 135 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit; 136 break; 137 } 138 139 platform_set_drvdata(pdev, dev); 140 SET_NETDEV_DEV(dev, &pdev->dev); 141 142 ret = register_c_can_dev(dev); 143 if (ret) { 144 dev_err(&pdev->dev, "registering %s failed (err=%d)\n", 145 KBUILD_MODNAME, ret); 146 goto exit_free_device; 147 } 148 149 dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n", 150 KBUILD_MODNAME, priv->base, dev->irq); 151 return 0; 152 153exit_free_device: 154 platform_set_drvdata(pdev, NULL); 155 free_c_can_dev(dev); 156exit_iounmap: 157 iounmap(addr); 158exit_release_mem: 159 release_mem_region(mem->start, resource_size(mem)); 160exit_free_clk: 161#ifdef CONFIG_HAVE_CLK 162 clk_put(clk); 163exit: 164#endif 165 dev_err(&pdev->dev, "probe failed\n"); 166 167 return ret; 168} 169 170static int __devexit c_can_plat_remove(struct platform_device *pdev) 171{ 172 struct net_device *dev = platform_get_drvdata(pdev); 173 struct c_can_priv *priv = netdev_priv(dev); 174 struct resource *mem; 175 176 unregister_c_can_dev(dev); 177 platform_set_drvdata(pdev, NULL); 178 179 free_c_can_dev(dev); 180 iounmap(priv->base); 181 182 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 183 release_mem_region(mem->start, resource_size(mem)); 184 185#ifdef CONFIG_HAVE_CLK 186 clk_put(priv->priv); 187#endif 188 189 return 0; 190} 191 192static struct platform_driver c_can_plat_driver = { 193 .driver = { 194 .name = KBUILD_MODNAME, 195 .owner = THIS_MODULE, 196 }, 197 .probe = c_can_plat_probe, 198 .remove = __devexit_p(c_can_plat_remove), 199}; 200 201module_platform_driver(c_can_plat_driver); 202 203MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>"); 204MODULE_LICENSE("GPL v2"); 205MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller"); 206