c_can_platform.c 10.8 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
/*
 * Platform CAN bus driver for Bosch C_CAN controller
 *
 * Copyright (C) 2010 ST Microelectronics
 * Bhupesh Sharma <bhupesh.sharma@st.com>
 *
 * Borrowed heavily from the C_CAN driver originally written by:
 * Copyright (C) 2007
 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix <s.hauer@pengutronix.de>
 * - Simon Kallweit, intefo AG <simon.kallweit@intefo.ch>
 *
 * Bosch C_CAN controller is compliant to CAN protocol version 2.0 part A and B.
 * Bosch C_CAN user manual can be obtained from:
 * http://www.semiconductors.bosch.de/media/en/pdf/ipmodules_1/c_can/
 * users_manual_c_can.pdf
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
33 34
#include <linux/of.h>
#include <linux/of_device.h>
35 36 37 38 39

#include <linux/can/dev.h>

#include "c_can.h"

40 41 42
#define CAN_RAMINIT_START_MASK(i)	(0x001 << (i))
#define CAN_RAMINIT_DONE_MASK(i)	(0x100 << (i))
#define CAN_RAMINIT_ALL_MASK(i)		(0x101 << (i))
43
#define DCAN_RAM_INIT_BIT		(1 << 3)
44
static DEFINE_SPINLOCK(raminit_lock);
45 46 47 48 49 50
/*
 * 16-bit c_can registers can be arranged differently in the memory
 * architecture of different implementations. For example: 16-bit
 * registers can be aligned to a 16-bit boundary or 32-bit boundary etc.
 * 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,
52
						enum reg index)
53
{
54
	return readw(priv->base + priv->regs[index]);
55 56
}

57
static void c_can_plat_write_reg_aligned_to_16bit(const struct c_can_priv *priv,
58
						enum reg index, u16 val)
59
{
60
	writew(val, priv->base + priv->regs[index]);
61 62
}

63
static u16 c_can_plat_read_reg_aligned_to_32bit(const struct c_can_priv *priv,
64
						enum reg index)
65
{
66
	return readw(priv->base + 2 * priv->regs[index]);
67 68
}

69
static void c_can_plat_write_reg_aligned_to_32bit(const struct c_can_priv *priv,
70
						enum reg index, u16 val)
71
{
72
	writew(val, priv->base + 2 * priv->regs[index]);
73 74
}

75
static void c_can_hw_raminit_wait_ti(const struct c_can_priv *priv, u32 mask,
76 77 78 79 80 81 82 83
				  u32 val)
{
	/* We look only at the bits of our instance. */
	val &= mask;
	while ((readl(priv->raminit_ctrlreg) & mask) != val)
		udelay(1);
}

84
static void c_can_hw_raminit_ti(const struct c_can_priv *priv, bool enable)
85
{
86 87
	u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance);
	u32 ctrl;
88

89 90 91 92 93 94 95 96 97 98 99
	spin_lock(&raminit_lock);

	ctrl = readl(priv->raminit_ctrlreg);
	/* We clear the done and start bit first. The start bit is
	 * looking at the 0 -> transition, but is not self clearing;
	 * And we clear the init done bit as well.
	 */
	ctrl &= ~CAN_RAMINIT_START_MASK(priv->instance);
	ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
	writel(ctrl, priv->raminit_ctrlreg);
	ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance);
100
	c_can_hw_raminit_wait_ti(priv, ctrl, mask);
101 102 103 104 105 106

	if (enable) {
		/* Set start bit and wait for the done bit. */
		ctrl |= CAN_RAMINIT_START_MASK(priv->instance);
		writel(ctrl, priv->raminit_ctrlreg);
		ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
107
		c_can_hw_raminit_wait_ti(priv, ctrl, mask);
108 109
	}
	spin_unlock(&raminit_lock);
110 111
}

112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139
static u32 c_can_plat_read_reg32(const struct c_can_priv *priv, enum reg index)
{
	u32 val;

	val = priv->read_reg(priv, index);
	val |= ((u32) priv->read_reg(priv, index + 1)) << 16;

	return val;
}

static void c_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index,
		u32 val)
{
	priv->write_reg(priv, index + 1, val >> 16);
	priv->write_reg(priv, index, val);
}

static u32 d_can_plat_read_reg32(const struct c_can_priv *priv, enum reg index)
{
	return readl(priv->base + priv->regs[index]);
}

static void d_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index,
		u32 val)
{
	writel(val, priv->base + priv->regs[index]);
}

140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161
static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask)
{
	while (priv->read_reg32(priv, C_CAN_FUNCTION_REG) & mask)
		udelay(1);
}

static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
{
	u32 ctrl;

	ctrl = priv->read_reg32(priv, C_CAN_FUNCTION_REG);
	ctrl &= ~DCAN_RAM_INIT_BIT;
	priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl);
	c_can_hw_raminit_wait(priv, ctrl);

	if (enable) {
		ctrl |= DCAN_RAM_INIT_BIT;
		priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl);
		c_can_hw_raminit_wait(priv, ctrl);
	}
}

162 163 164 165 166 167 168 169 170 171 172 173 174 175 176
static struct platform_device_id c_can_id_table[] = {
	[BOSCH_C_CAN_PLATFORM] = {
		.name = KBUILD_MODNAME,
		.driver_data = BOSCH_C_CAN,
	},
	[BOSCH_C_CAN] = {
		.name = "c_can",
		.driver_data = BOSCH_C_CAN,
	},
	[BOSCH_D_CAN] = {
		.name = "d_can",
		.driver_data = BOSCH_D_CAN,
	}, {
	}
};
177
MODULE_DEVICE_TABLE(platform, c_can_id_table);
178 179 180 181 182 183

static const struct of_device_id c_can_of_table[] = {
	{ .compatible = "bosch,c_can", .data = &c_can_id_table[BOSCH_C_CAN] },
	{ .compatible = "bosch,d_can", .data = &c_can_id_table[BOSCH_D_CAN] },
	{ /* sentinel */ },
};
184
MODULE_DEVICE_TABLE(of, c_can_of_table);
185

B
Bill Pemberton 已提交
186
static int c_can_plat_probe(struct platform_device *pdev)
187 188 189 190 191
{
	int ret;
	void __iomem *addr;
	struct net_device *dev;
	struct c_can_priv *priv;
192
	const struct of_device_id *match;
193
	const struct platform_device_id *id;
194
	struct resource *mem, *res;
195
	int irq;
196 197
	struct clk *clk;

198 199 200 201 202 203 204 205 206 207 208 209
	if (pdev->dev.of_node) {
		match = of_match_device(c_can_of_table, &pdev->dev);
		if (!match) {
			dev_err(&pdev->dev, "Failed to find matching dt id\n");
			ret = -EINVAL;
			goto exit;
		}
		id = match->data;
	} else {
		id = platform_get_device_id(pdev);
	}

210 211 212 213 214 215 216 217 218 219
	/* get the appropriate clk */
	clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(clk)) {
		dev_err(&pdev->dev, "no clock defined\n");
		ret = -ENODEV;
		goto exit;
	}

	/* get the platform data */
	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
220 221
	irq = platform_get_irq(pdev, 0);
	if (!mem || irq <= 0) {
222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247
		ret = -ENODEV;
		goto exit_free_clk;
	}

	if (!request_mem_region(mem->start, resource_size(mem),
				KBUILD_MODNAME)) {
		dev_err(&pdev->dev, "resource unavailable\n");
		ret = -ENODEV;
		goto exit_free_clk;
	}

	addr = ioremap(mem->start, resource_size(mem));
	if (!addr) {
		dev_err(&pdev->dev, "failed to map can port\n");
		ret = -ENOMEM;
		goto exit_release_mem;
	}

	/* allocate the c_can device */
	dev = alloc_c_can_dev();
	if (!dev) {
		ret = -ENOMEM;
		goto exit_iounmap;
	}

	priv = netdev_priv(dev);
248
	switch (id->driver_data) {
249
	case BOSCH_C_CAN:
250 251 252 253 254
		priv->regs = reg_map_c_can;
		switch (mem->flags & IORESOURCE_MEM_TYPE_MASK) {
		case IORESOURCE_MEM_32BIT:
			priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
			priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
255 256
			priv->read_reg32 = c_can_plat_read_reg32;
			priv->write_reg32 = c_can_plat_write_reg32;
257 258 259 260 261
			break;
		case IORESOURCE_MEM_16BIT:
		default:
			priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
			priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
262 263
			priv->read_reg32 = c_can_plat_read_reg32;
			priv->write_reg32 = c_can_plat_write_reg32;
264 265 266
			break;
		}
		break;
267
	case BOSCH_D_CAN:
268 269 270 271
		priv->regs = reg_map_d_can;
		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
272 273
		priv->read_reg32 = d_can_plat_read_reg32;
		priv->write_reg32 = d_can_plat_write_reg32;
274 275 276 277 278 279 280

		if (pdev->dev.of_node)
			priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
		else
			priv->instance = pdev->id;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
281 282 283 284 285 286 287 288 289
		/* Not all D_CAN modules have a separate register for the D_CAN
		 * RAM initialization. Use default RAM init bit in D_CAN module
		 * if not specified in DT.
		 */
		if (!res) {
			priv->raminit = c_can_hw_raminit;
			break;
		}

290
		priv->raminit_ctrlreg = devm_ioremap_resource(&pdev->dev, res);
291
		if (IS_ERR(priv->raminit_ctrlreg) || priv->instance < 0)
292 293
			dev_info(&pdev->dev, "control memory is not used for raminit\n");
		else
294
			priv->raminit = c_can_hw_raminit_ti;
295 296 297 298 299
		break;
	default:
		ret = -EINVAL;
		goto exit_free_device;
	}
300

301
	dev->irq = irq;
302
	priv->base = addr;
303
	priv->device = &pdev->dev;
304 305
	priv->can.clock.freq = clk_get_rate(clk);
	priv->priv = clk;
306
	priv->type = id->driver_data;
307 308 309 310 311 312 313 314 315 316 317 318

	platform_set_drvdata(pdev, dev);
	SET_NETDEV_DEV(dev, &pdev->dev);

	ret = register_c_can_dev(dev);
	if (ret) {
		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
			KBUILD_MODNAME, ret);
		goto exit_free_device;
	}

	dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
319
		 KBUILD_MODNAME, priv->base, dev->irq);
320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335
	return 0;

exit_free_device:
	free_c_can_dev(dev);
exit_iounmap:
	iounmap(addr);
exit_release_mem:
	release_mem_region(mem->start, resource_size(mem));
exit_free_clk:
	clk_put(clk);
exit:
	dev_err(&pdev->dev, "probe failed\n");

	return ret;
}

B
Bill Pemberton 已提交
336
static int c_can_plat_remove(struct platform_device *pdev)
337 338 339 340 341 342 343 344
{
	struct net_device *dev = platform_get_drvdata(pdev);
	struct c_can_priv *priv = netdev_priv(dev);
	struct resource *mem;

	unregister_c_can_dev(dev);

	free_c_can_dev(dev);
345
	iounmap(priv->base);
346 347 348 349 350 351 352 353 354

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(mem->start, resource_size(mem));

	clk_put(priv->priv);

	return 0;
}

355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413
#ifdef CONFIG_PM
static int c_can_suspend(struct platform_device *pdev, pm_message_t state)
{
	int ret;
	struct net_device *ndev = platform_get_drvdata(pdev);
	struct c_can_priv *priv = netdev_priv(ndev);

	if (priv->type != BOSCH_D_CAN) {
		dev_warn(&pdev->dev, "Not supported\n");
		return 0;
	}

	if (netif_running(ndev)) {
		netif_stop_queue(ndev);
		netif_device_detach(ndev);
	}

	ret = c_can_power_down(ndev);
	if (ret) {
		netdev_err(ndev, "failed to enter power down mode\n");
		return ret;
	}

	priv->can.state = CAN_STATE_SLEEPING;

	return 0;
}

static int c_can_resume(struct platform_device *pdev)
{
	int ret;
	struct net_device *ndev = platform_get_drvdata(pdev);
	struct c_can_priv *priv = netdev_priv(ndev);

	if (priv->type != BOSCH_D_CAN) {
		dev_warn(&pdev->dev, "Not supported\n");
		return 0;
	}

	ret = c_can_power_up(ndev);
	if (ret) {
		netdev_err(ndev, "Still in power down mode\n");
		return ret;
	}

	priv->can.state = CAN_STATE_ERROR_ACTIVE;

	if (netif_running(ndev)) {
		netif_device_attach(ndev);
		netif_start_queue(ndev);
	}

	return 0;
}
#else
#define c_can_suspend NULL
#define c_can_resume NULL
#endif

414 415 416 417
static struct platform_driver c_can_plat_driver = {
	.driver = {
		.name = KBUILD_MODNAME,
		.owner = THIS_MODULE,
418
		.of_match_table = c_can_of_table,
419 420
	},
	.probe = c_can_plat_probe,
B
Bill Pemberton 已提交
421
	.remove = c_can_plat_remove,
422 423
	.suspend = c_can_suspend,
	.resume = c_can_resume,
424
	.id_table = c_can_id_table,
425 426
};

427
module_platform_driver(c_can_plat_driver);
428 429 430 431

MODULE_AUTHOR("Bhupesh Sharma <bhupesh.sharma@st.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Platform CAN bus driver for Bosch C_CAN controller");