2 * Platform CAN bus driver for Bosch C_CAN controller
4 * Copyright (C) 2010 ST Microelectronics
5 * Bhupesh Sharma <bhupesh.sharma@st.com>
7 * Borrowed heavily from the C_CAN driver originally written by:
9 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de>
10 * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch>
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
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.
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>
31 #include <linux/platform_device.h>
32 #include <linux/clk.h>
34 #include <linux/of_device.h>
36 #include <linux/can/dev.h>
40 #define CAN_RAMINIT_START_MASK(i) (0x001 << (i))
41 #define CAN_RAMINIT_DONE_MASK(i) (0x100 << (i))
42 #define CAN_RAMINIT_ALL_MASK(i) (0x101 << (i))
43 static DEFINE_SPINLOCK(raminit_lock);
45 * 16-bit c_can registers can be arranged differently in the memory
46 * architecture of different implementations. For example: 16-bit
47 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
48 * Handle the same by providing a common read/write interface.
50 static u16 c_can_plat_read_reg_aligned_to_16bit(struct c_can_priv *priv,
53 return readw(priv->base + priv->regs[index]);
56 static void c_can_plat_write_reg_aligned_to_16bit(struct c_can_priv *priv,
57 enum reg index, u16 val)
59 writew(val, priv->base + priv->regs[index]);
62 static u16 c_can_plat_read_reg_aligned_to_32bit(struct c_can_priv *priv,
65 return readw(priv->base + 2 * priv->regs[index]);
68 static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
69 enum reg index, u16 val)
71 writew(val, priv->base + 2 * priv->regs[index]);
74 static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask,
77 /* We look only at the bits of our instance. */
79 while ((readl(priv->raminit_ctrlreg) & mask) != val)
83 static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
85 u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance);
88 spin_lock(&raminit_lock);
90 ctrl = readl(priv->raminit_ctrlreg);
91 /* We clear the done and start bit first. The start bit is
92 * looking at the 0 -> transition, but is not self clearing;
93 * And we clear the init done bit as well.
95 ctrl &= ~CAN_RAMINIT_START_MASK(priv->instance);
96 ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
97 writel(ctrl, priv->raminit_ctrlreg);
98 ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance);
99 c_can_hw_raminit_wait(priv, ctrl, mask);
102 /* Set start bit and wait for the done bit. */
103 ctrl |= CAN_RAMINIT_START_MASK(priv->instance);
104 writel(ctrl, priv->raminit_ctrlreg);
105 ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
106 c_can_hw_raminit_wait(priv, ctrl, mask);
108 spin_unlock(&raminit_lock);
111 static struct platform_device_id c_can_id_table[] = {
112 [BOSCH_C_CAN_PLATFORM] = {
113 .name = KBUILD_MODNAME,
114 .driver_data = BOSCH_C_CAN,
118 .driver_data = BOSCH_C_CAN,
122 .driver_data = BOSCH_D_CAN,
126 MODULE_DEVICE_TABLE(platform, c_can_id_table);
128 static const struct of_device_id c_can_of_table[] = {
129 { .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
130 { .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
133 MODULE_DEVICE_TABLE(of, c_can_of_table);
135 static int c_can_plat_probe(struct platform_device *pdev)
139 struct net_device *dev;
140 struct c_can_priv *priv;
141 const struct of_device_id *match;
142 const struct platform_device_id *id;
143 struct resource *mem, *res;
147 if (pdev->dev.of_node) {
148 match = of_match_device(c_can_of_table, &pdev->dev);
150 dev_err(&pdev->dev, "Failed to find matching dt id\n");
156 id = platform_get_device_id(pdev);
159 /* get the appropriate clk */
160 clk = clk_get(&pdev->dev, NULL);
162 dev_err(&pdev->dev, "no clock defined\n");
167 /* get the platform data */
168 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
169 irq = platform_get_irq(pdev, 0);
170 if (!mem || irq <= 0) {
175 if (!request_mem_region(mem->start, resource_size(mem),
177 dev_err(&pdev->dev, "resource unavailable\n");
182 addr = ioremap(mem->start, resource_size(mem));
184 dev_err(&pdev->dev, "failed to map can port\n");
186 goto exit_release_mem;
189 /* allocate the c_can device */
190 dev = alloc_c_can_dev();
196 priv = netdev_priv(dev);
197 switch (id->driver_data) {
199 priv->regs = reg_map_c_can;
200 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
201 case IORESOURCE_MEM_32BIT:
202 priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
203 priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
205 case IORESOURCE_MEM_16BIT:
207 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
208 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
213 priv->regs = reg_map_d_can;
214 priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
215 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
216 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
218 if (pdev->dev.of_node)
219 priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
221 priv->instance = pdev->id;
223 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
224 priv->raminit_ctrlreg = devm_ioremap_resource(&pdev->dev, res);
225 if (IS_ERR(priv->raminit_ctrlreg) || (int)priv->instance < 0)
226 dev_info(&pdev->dev, "control memory is not used for raminit\n");
228 priv->raminit = c_can_hw_raminit;
232 goto exit_free_device;
237 priv->device = &pdev->dev;
238 priv->can.clock.freq = clk_get_rate(clk);
240 priv->type = id->driver_data;
242 platform_set_drvdata(pdev, dev);
243 SET_NETDEV_DEV(dev, &pdev->dev);
245 ret = register_c_can_dev(dev);
247 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
248 KBUILD_MODNAME, ret);
249 goto exit_free_device;
252 dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
253 KBUILD_MODNAME, priv->base, dev->irq);
261 release_mem_region(mem->start, resource_size(mem));
265 dev_err(&pdev->dev, "probe failed\n");
270 static int c_can_plat_remove(struct platform_device *pdev)
272 struct net_device *dev = platform_get_drvdata(pdev);
273 struct c_can_priv *priv = netdev_priv(dev);
274 struct resource *mem;
276 unregister_c_can_dev(dev);
281 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
282 release_mem_region(mem->start, resource_size(mem));
290 static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
293 struct net_device *ndev = platform_get_drvdata(pdev);
294 struct c_can_priv *priv = netdev_priv(ndev);
296 if (priv->type != BOSCH_D_CAN) {
297 dev_warn(&pdev->dev, "Not supported\n");
301 if (netif_running(ndev)) {
302 netif_stop_queue(ndev);
303 netif_device_detach(ndev);
306 ret = c_can_power_down(ndev);
308 netdev_err(ndev, "failed to enter power down mode\n");
312 priv->can.state = CAN_STATE_SLEEPING;
317 static int c_can_resume(struct platform_device *pdev)
320 struct net_device *ndev = platform_get_drvdata(pdev);
321 struct c_can_priv *priv = netdev_priv(ndev);
323 if (priv->type != BOSCH_D_CAN) {
324 dev_warn(&pdev->dev, "Not supported\n");
328 ret = c_can_power_up(ndev);
330 netdev_err(ndev, "Still in power down mode\n");
334 priv->can.state = CAN_STATE_ERROR_ACTIVE;
336 if (netif_running(ndev)) {
337 netif_device_attach(ndev);
338 netif_start_queue(ndev);
344 #define c_can_suspend NULL
345 #define c_can_resume NULL
348 static struct platform_driver c_can_plat_driver = {
350 .name = KBUILD_MODNAME,
351 .owner = THIS_MODULE,
352 .of_match_table = c_can_of_table,
354 .probe = c_can_plat_probe,
355 .remove = c_can_plat_remove,
356 .suspend = c_can_suspend,
357 .resume = c_can_resume,
358 .id_table = c_can_id_table,
361 module_platform_driver(c_can_plat_driver);
363 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
364 MODULE_LICENSE("GPL v2");
365 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");