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 #define DCAN_RAM_INIT_BIT (1 << 3)
44 static DEFINE_SPINLOCK(raminit_lock);
46 * 16-bit c_can registers can be arranged differently in the memory
47 * architecture of different implementations. For example: 16-bit
48 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
49 * Handle the same by providing a common read/write interface.
51 static u16 c_can_plat_read_reg_aligned_to_16bit(const struct c_can_priv *priv,
54 return readw(priv->base + priv->regs[index]);
57 static void c_can_plat_write_reg_aligned_to_16bit(const struct c_can_priv *priv,
58 enum reg index, u16 val)
60 writew(val, priv->base + priv->regs[index]);
63 static u16 c_can_plat_read_reg_aligned_to_32bit(const struct c_can_priv *priv,
66 return readw(priv->base + 2 * priv->regs[index]);
69 static void c_can_plat_write_reg_aligned_to_32bit(const struct c_can_priv *priv,
70 enum reg index, u16 val)
72 writew(val, priv->base + 2 * priv->regs[index]);
75 static void c_can_hw_raminit_wait_ti(const struct c_can_priv *priv, u32 mask,
78 /* We look only at the bits of our instance. */
80 while ((readl(priv->raminit_ctrlreg) & mask) != val)
84 static void c_can_hw_raminit_ti(const struct c_can_priv *priv, bool enable)
86 u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance);
89 spin_lock(&raminit_lock);
91 ctrl = readl(priv->raminit_ctrlreg);
92 /* We clear the done and start bit first. The start bit is
93 * looking at the 0 -> transition, but is not self clearing;
94 * And we clear the init done bit as well.
96 ctrl &= ~CAN_RAMINIT_START_MASK(priv->instance);
97 ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
98 writel(ctrl, priv->raminit_ctrlreg);
99 ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance);
100 c_can_hw_raminit_wait_ti(priv, ctrl, mask);
103 /* Set start bit and wait for the done bit. */
104 ctrl |= CAN_RAMINIT_START_MASK(priv->instance);
105 writel(ctrl, priv->raminit_ctrlreg);
106 ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
107 c_can_hw_raminit_wait_ti(priv, ctrl, mask);
109 spin_unlock(&raminit_lock);
112 static u32 c_can_plat_read_reg32(const struct c_can_priv *priv, enum reg index)
116 val = priv->read_reg(priv, index);
117 val |= ((u32) priv->read_reg(priv, index + 1)) << 16;
122 static void c_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index,
125 priv->write_reg(priv, index + 1, val >> 16);
126 priv->write_reg(priv, index, val);
129 static u32 d_can_plat_read_reg32(const struct c_can_priv *priv, enum reg index)
131 return readl(priv->base + priv->regs[index]);
134 static void d_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index,
137 writel(val, priv->base + priv->regs[index]);
140 static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask)
142 while (priv->read_reg32(priv, C_CAN_FUNCTION_REG) & mask)
146 static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
150 ctrl = priv->read_reg32(priv, C_CAN_FUNCTION_REG);
151 ctrl &= ~DCAN_RAM_INIT_BIT;
152 priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl);
153 c_can_hw_raminit_wait(priv, ctrl);
156 ctrl |= DCAN_RAM_INIT_BIT;
157 priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl);
158 c_can_hw_raminit_wait(priv, ctrl);
162 static struct platform_device_id c_can_id_table[] = {
163 [BOSCH_C_CAN_PLATFORM] = {
164 .name = KBUILD_MODNAME,
165 .driver_data = BOSCH_C_CAN,
169 .driver_data = BOSCH_C_CAN,
173 .driver_data = BOSCH_D_CAN,
177 MODULE_DEVICE_TABLE(platform, c_can_id_table);
179 static const struct of_device_id c_can_of_table[] = {
180 { .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
181 { .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
184 MODULE_DEVICE_TABLE(of, c_can_of_table);
186 static int c_can_plat_probe(struct platform_device *pdev)
190 struct net_device *dev;
191 struct c_can_priv *priv;
192 const struct of_device_id *match;
193 const struct platform_device_id *id;
194 struct resource *mem, *res;
198 if (pdev->dev.of_node) {
199 match = of_match_device(c_can_of_table, &pdev->dev);
201 dev_err(&pdev->dev, "Failed to find matching dt id\n");
207 id = platform_get_device_id(pdev);
210 /* get the appropriate clk */
211 clk = devm_clk_get(&pdev->dev, NULL);
217 /* get the platform data */
218 irq = platform_get_irq(pdev, 0);
224 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
225 addr = devm_ioremap_resource(&pdev->dev, mem);
231 /* allocate the c_can device */
232 dev = alloc_c_can_dev();
238 priv = netdev_priv(dev);
239 switch (id->driver_data) {
241 priv->regs = reg_map_c_can;
242 switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
243 case IORESOURCE_MEM_32BIT:
244 priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
245 priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
246 priv->read_reg32 = c_can_plat_read_reg32;
247 priv->write_reg32 = c_can_plat_write_reg32;
249 case IORESOURCE_MEM_16BIT:
251 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
252 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
253 priv->read_reg32 = c_can_plat_read_reg32;
254 priv->write_reg32 = c_can_plat_write_reg32;
259 priv->regs = reg_map_d_can;
260 priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
261 priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
262 priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
263 priv->read_reg32 = d_can_plat_read_reg32;
264 priv->write_reg32 = d_can_plat_write_reg32;
266 if (pdev->dev.of_node)
267 priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
269 priv->instance = pdev->id;
271 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
272 /* Not all D_CAN modules have a separate register for the D_CAN
273 * RAM initialization. Use default RAM init bit in D_CAN module
274 * if not specified in DT.
277 priv->raminit = c_can_hw_raminit;
281 priv->raminit_ctrlreg = devm_ioremap(&pdev->dev, res->start,
283 if (IS_ERR(priv->raminit_ctrlreg) || priv->instance < 0)
284 dev_info(&pdev->dev, "control memory is not used for raminit\n");
286 priv->raminit = c_can_hw_raminit_ti;
290 goto exit_free_device;
295 priv->device = &pdev->dev;
296 priv->can.clock.freq = clk_get_rate(clk);
298 priv->type = id->driver_data;
300 platform_set_drvdata(pdev, dev);
301 SET_NETDEV_DEV(dev, &pdev->dev);
303 ret = register_c_can_dev(dev);
305 dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
306 KBUILD_MODNAME, ret);
307 goto exit_free_device;
310 dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
311 KBUILD_MODNAME, priv->base, dev->irq);
317 dev_err(&pdev->dev, "probe failed\n");
322 static int c_can_plat_remove(struct platform_device *pdev)
324 struct net_device *dev = platform_get_drvdata(pdev);
326 unregister_c_can_dev(dev);
334 static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
337 struct net_device *ndev = platform_get_drvdata(pdev);
338 struct c_can_priv *priv = netdev_priv(ndev);
340 if (priv->type != BOSCH_D_CAN) {
341 dev_warn(&pdev->dev, "Not supported\n");
345 if (netif_running(ndev)) {
346 netif_stop_queue(ndev);
347 netif_device_detach(ndev);
350 ret = c_can_power_down(ndev);
352 netdev_err(ndev, "failed to enter power down mode\n");
356 priv->can.state = CAN_STATE_SLEEPING;
361 static int c_can_resume(struct platform_device *pdev)
364 struct net_device *ndev = platform_get_drvdata(pdev);
365 struct c_can_priv *priv = netdev_priv(ndev);
367 if (priv->type != BOSCH_D_CAN) {
368 dev_warn(&pdev->dev, "Not supported\n");
372 ret = c_can_power_up(ndev);
374 netdev_err(ndev, "Still in power down mode\n");
378 priv->can.state = CAN_STATE_ERROR_ACTIVE;
380 if (netif_running(ndev)) {
381 netif_device_attach(ndev);
382 netif_start_queue(ndev);
388 #define c_can_suspend NULL
389 #define c_can_resume NULL
392 static struct platform_driver c_can_plat_driver = {
394 .name = KBUILD_MODNAME,
395 .owner = THIS_MODULE,
396 .of_match_table = c_can_of_table,
398 .probe = c_can_plat_probe,
399 .remove = c_can_plat_remove,
400 .suspend = c_can_suspend,
401 .resume = c_can_resume,
402 .id_table = c_can_id_table,
405 module_platform_driver(c_can_plat_driver);
407 MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
408 MODULE_LICENSE("GPL v2");
409 MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");