1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * CAN bus driver for the Freescale MPC5xxx embedded CPU. 4 * 5 * Copyright (C) 2004-2005 Andrey Volkov <avolkov@varma-el.com>, 6 * Varma Electronics Oy 7 * Copyright (C) 2008-2009 Wolfgang Grandegger <wg@grandegger.com> 8 * Copyright (C) 2009 Wolfram Sang, Pengutronix <kernel@pengutronix.de> 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/interrupt.h> 14 #include <linux/platform_device.h> 15 #include <linux/netdevice.h> 16 #include <linux/can/dev.h> 17 #include <linux/of_address.h> 18 #include <linux/of_irq.h> 19 #include <linux/of_platform.h> 20 #include <sysdev/fsl_soc.h> 21 #include <linux/clk.h> 22 #include <linux/io.h> 23 #include <asm/mpc52xx.h> 24 25 #include "mscan.h" 26 27 #define DRV_NAME "mpc5xxx_can" 28 29 struct mpc5xxx_can_data { 30 unsigned int type; 31 u32 (*get_clock)(struct platform_device *ofdev, const char *clock_name, 32 int *mscan_clksrc); 33 void (*put_clock)(struct platform_device *ofdev); 34 }; 35 36 #ifdef CONFIG_PPC_MPC52xx 37 static const struct of_device_id mpc52xx_cdm_ids[] = { 38 { .compatible = "fsl,mpc5200-cdm", }, 39 {} 40 }; 41 42 static u32 mpc52xx_can_get_clock(struct platform_device *ofdev, 43 const char *clock_name, int *mscan_clksrc) 44 { 45 unsigned int pvr; 46 struct mpc52xx_cdm __iomem *cdm; 47 struct device_node *np_cdm; 48 unsigned int freq; 49 u32 val; 50 51 pvr = mfspr(SPRN_PVR); 52 53 /* 54 * Either the oscillator clock (SYS_XTAL_IN) or the IP bus clock 55 * (IP_CLK) can be selected as MSCAN clock source. According to 56 * the MPC5200 user's manual, the oscillator clock is the better 57 * choice as it has less jitter. For this reason, it is selected 58 * by default. Unfortunately, it can not be selected for the old 59 * MPC5200 Rev. A chips due to a hardware bug (check errata). 60 */ 61 if (clock_name && strcmp(clock_name, "ip") == 0) 62 *mscan_clksrc = MSCAN_CLKSRC_BUS; 63 else 64 *mscan_clksrc = MSCAN_CLKSRC_XTAL; 65 66 freq = mpc5xxx_get_bus_frequency(&ofdev->dev); 67 if (!freq) 68 return 0; 69 70 if (*mscan_clksrc == MSCAN_CLKSRC_BUS || pvr == 0x80822011) 71 return freq; 72 73 /* Determine SYS_XTAL_IN frequency from the clock domain settings */ 74 np_cdm = of_find_matching_node(NULL, mpc52xx_cdm_ids); 75 if (!np_cdm) { 76 dev_err(&ofdev->dev, "can't get clock node!\n"); 77 return 0; 78 } 79 cdm = of_iomap(np_cdm, 0); 80 if (!cdm) { 81 of_node_put(np_cdm); 82 dev_err(&ofdev->dev, "can't map clock node!\n"); 83 return 0; 84 } 85 86 if (in_8(&cdm->ipb_clk_sel) & 0x1) 87 freq *= 2; 88 val = in_be32(&cdm->rstcfg); 89 90 freq *= (val & (1 << 5)) ? 8 : 4; 91 freq /= (val & (1 << 6)) ? 12 : 16; 92 93 of_node_put(np_cdm); 94 iounmap(cdm); 95 96 return freq; 97 } 98 #else /* !CONFIG_PPC_MPC52xx */ 99 static u32 mpc52xx_can_get_clock(struct platform_device *ofdev, 100 const char *clock_name, int *mscan_clksrc) 101 { 102 return 0; 103 } 104 #endif /* CONFIG_PPC_MPC52xx */ 105 106 #ifdef CONFIG_PPC_MPC512x 107 static u32 mpc512x_can_get_clock(struct platform_device *ofdev, 108 const char *clock_source, int *mscan_clksrc) 109 { 110 struct device_node *np; 111 u32 clockdiv; 112 enum { 113 CLK_FROM_AUTO, 114 CLK_FROM_IPS, 115 CLK_FROM_SYS, 116 CLK_FROM_REF, 117 } clk_from; 118 struct clk *clk_in, *clk_can; 119 unsigned long freq_calc; 120 struct mscan_priv *priv; 121 struct clk *clk_ipg; 122 123 /* the caller passed in the clock source spec that was read from 124 * the device tree, get the optional clock divider as well 125 */ 126 np = ofdev->dev.of_node; 127 clockdiv = 1; 128 of_property_read_u32(np, "fsl,mscan-clock-divider", &clockdiv); 129 dev_dbg(&ofdev->dev, "device tree specs: clk src[%s] div[%d]\n", 130 clock_source ? clock_source : "<NULL>", clockdiv); 131 132 /* when clock-source is 'ip', the CANCTL1[CLKSRC] bit needs to 133 * get set, and the 'ips' clock is the input to the MSCAN 134 * component 135 * 136 * for clock-source values of 'ref' or 'sys' the CANCTL1[CLKSRC] 137 * bit needs to get cleared, an optional clock-divider may have 138 * been specified (the default value is 1), the appropriate 139 * MSCAN related MCLK is the input to the MSCAN component 140 * 141 * in the absence of a clock-source spec, first an optimal clock 142 * gets determined based on the 'sys' clock, if that fails the 143 * 'ref' clock is used 144 */ 145 clk_from = CLK_FROM_AUTO; 146 if (clock_source) { 147 /* interpret the device tree's spec for the clock source */ 148 if (!strcmp(clock_source, "ip")) 149 clk_from = CLK_FROM_IPS; 150 else if (!strcmp(clock_source, "sys")) 151 clk_from = CLK_FROM_SYS; 152 else if (!strcmp(clock_source, "ref")) 153 clk_from = CLK_FROM_REF; 154 else 155 goto err_invalid; 156 dev_dbg(&ofdev->dev, "got a clk source spec[%d]\n", clk_from); 157 } 158 if (clk_from == CLK_FROM_AUTO) { 159 /* no spec so far, try the 'sys' clock; round to the 160 * next MHz and see if we can get a multiple of 16MHz 161 */ 162 dev_dbg(&ofdev->dev, "no clk source spec, trying SYS\n"); 163 clk_in = devm_clk_get(&ofdev->dev, "sys"); 164 if (IS_ERR(clk_in)) 165 goto err_notavail; 166 freq_calc = clk_get_rate(clk_in); 167 freq_calc += 499999; 168 freq_calc /= 1000000; 169 freq_calc *= 1000000; 170 if ((freq_calc % 16000000) == 0) { 171 clk_from = CLK_FROM_SYS; 172 clockdiv = freq_calc / 16000000; 173 dev_dbg(&ofdev->dev, 174 "clk fit, sys[%lu] div[%d] freq[%lu]\n", 175 freq_calc, clockdiv, freq_calc / clockdiv); 176 } 177 } 178 if (clk_from == CLK_FROM_AUTO) { 179 /* no spec so far, use the 'ref' clock */ 180 dev_dbg(&ofdev->dev, "no clk source spec, trying REF\n"); 181 clk_in = devm_clk_get(&ofdev->dev, "ref"); 182 if (IS_ERR(clk_in)) 183 goto err_notavail; 184 clk_from = CLK_FROM_REF; 185 freq_calc = clk_get_rate(clk_in); 186 dev_dbg(&ofdev->dev, 187 "clk fit, ref[%lu] (no div) freq[%lu]\n", 188 freq_calc, freq_calc); 189 } 190 191 /* select IPS or MCLK as the MSCAN input (returned to the caller), 192 * setup the MCLK mux source and rate if applicable, apply the 193 * optionally specified or derived above divider, and determine 194 * the actual resulting clock rate to return to the caller 195 */ 196 switch (clk_from) { 197 case CLK_FROM_IPS: 198 clk_can = devm_clk_get(&ofdev->dev, "ips"); 199 if (IS_ERR(clk_can)) 200 goto err_notavail; 201 priv = netdev_priv(dev_get_drvdata(&ofdev->dev)); 202 priv->clk_can = clk_can; 203 freq_calc = clk_get_rate(clk_can); 204 *mscan_clksrc = MSCAN_CLKSRC_IPS; 205 dev_dbg(&ofdev->dev, "clk from IPS, clksrc[%d] freq[%lu]\n", 206 *mscan_clksrc, freq_calc); 207 break; 208 case CLK_FROM_SYS: 209 case CLK_FROM_REF: 210 clk_can = devm_clk_get(&ofdev->dev, "mclk"); 211 if (IS_ERR(clk_can)) 212 goto err_notavail; 213 priv = netdev_priv(dev_get_drvdata(&ofdev->dev)); 214 priv->clk_can = clk_can; 215 if (clk_from == CLK_FROM_SYS) 216 clk_in = devm_clk_get(&ofdev->dev, "sys"); 217 if (clk_from == CLK_FROM_REF) 218 clk_in = devm_clk_get(&ofdev->dev, "ref"); 219 if (IS_ERR(clk_in)) 220 goto err_notavail; 221 clk_set_parent(clk_can, clk_in); 222 freq_calc = clk_get_rate(clk_in); 223 freq_calc /= clockdiv; 224 clk_set_rate(clk_can, freq_calc); 225 freq_calc = clk_get_rate(clk_can); 226 *mscan_clksrc = MSCAN_CLKSRC_BUS; 227 dev_dbg(&ofdev->dev, "clk from MCLK, clksrc[%d] freq[%lu]\n", 228 *mscan_clksrc, freq_calc); 229 break; 230 default: 231 goto err_invalid; 232 } 233 234 /* the above clk_can item is used for the bitrate, access to 235 * the peripheral's register set needs the clk_ipg item 236 */ 237 clk_ipg = devm_clk_get(&ofdev->dev, "ipg"); 238 if (IS_ERR(clk_ipg)) 239 goto err_notavail_ipg; 240 if (clk_prepare_enable(clk_ipg)) 241 goto err_notavail_ipg; 242 priv = netdev_priv(dev_get_drvdata(&ofdev->dev)); 243 priv->clk_ipg = clk_ipg; 244 245 /* return the determined clock source rate */ 246 return freq_calc; 247 248 err_invalid: 249 dev_err(&ofdev->dev, "invalid clock source specification\n"); 250 /* clock source rate could not get determined */ 251 return 0; 252 253 err_notavail: 254 dev_err(&ofdev->dev, "cannot acquire or setup bitrate clock source\n"); 255 /* clock source rate could not get determined */ 256 return 0; 257 258 err_notavail_ipg: 259 dev_err(&ofdev->dev, "cannot acquire or setup register clock\n"); 260 /* clock source rate could not get determined */ 261 return 0; 262 } 263 264 static void mpc512x_can_put_clock(struct platform_device *ofdev) 265 { 266 struct mscan_priv *priv; 267 268 priv = netdev_priv(dev_get_drvdata(&ofdev->dev)); 269 if (priv->clk_ipg) 270 clk_disable_unprepare(priv->clk_ipg); 271 } 272 #else /* !CONFIG_PPC_MPC512x */ 273 static u32 mpc512x_can_get_clock(struct platform_device *ofdev, 274 const char *clock_name, int *mscan_clksrc) 275 { 276 return 0; 277 } 278 #define mpc512x_can_put_clock NULL 279 #endif /* CONFIG_PPC_MPC512x */ 280 281 static const struct of_device_id mpc5xxx_can_table[]; 282 static int mpc5xxx_can_probe(struct platform_device *ofdev) 283 { 284 const struct mpc5xxx_can_data *data; 285 struct device_node *np = ofdev->dev.of_node; 286 struct net_device *dev; 287 struct mscan_priv *priv; 288 void __iomem *base; 289 const char *clock_name = NULL; 290 int irq, mscan_clksrc = 0; 291 int err = -ENOMEM; 292 293 data = of_device_get_match_data(&ofdev->dev); 294 if (!data) 295 return -EINVAL; 296 297 base = of_iomap(np, 0); 298 if (!base) 299 return dev_err_probe(&ofdev->dev, err, "couldn't ioremap\n"); 300 301 irq = irq_of_parse_and_map(np, 0); 302 if (!irq) { 303 dev_err(&ofdev->dev, "no irq found\n"); 304 err = -ENODEV; 305 goto exit_unmap_mem; 306 } 307 308 dev = alloc_mscandev(); 309 if (!dev) 310 goto exit_dispose_irq; 311 platform_set_drvdata(ofdev, dev); 312 SET_NETDEV_DEV(dev, &ofdev->dev); 313 314 priv = netdev_priv(dev); 315 priv->reg_base = base; 316 dev->irq = irq; 317 318 clock_name = of_get_property(np, "fsl,mscan-clock-source", NULL); 319 320 priv->type = data->type; 321 priv->can.clock.freq = data->get_clock(ofdev, clock_name, 322 &mscan_clksrc); 323 if (!priv->can.clock.freq) { 324 dev_err(&ofdev->dev, "couldn't get MSCAN clock properties\n"); 325 goto exit_put_clock; 326 } 327 328 err = register_mscandev(dev, mscan_clksrc); 329 if (err) { 330 dev_err(&ofdev->dev, "registering %s failed (err=%d)\n", 331 DRV_NAME, err); 332 goto exit_put_clock; 333 } 334 335 dev_info(&ofdev->dev, "MSCAN at 0x%p, irq %d, clock %d Hz\n", 336 priv->reg_base, dev->irq, priv->can.clock.freq); 337 338 return 0; 339 340 exit_put_clock: 341 if (data->put_clock) 342 data->put_clock(ofdev); 343 free_candev(dev); 344 exit_dispose_irq: 345 irq_dispose_mapping(irq); 346 exit_unmap_mem: 347 iounmap(base); 348 349 return err; 350 } 351 352 static void mpc5xxx_can_remove(struct platform_device *ofdev) 353 { 354 const struct of_device_id *match; 355 const struct mpc5xxx_can_data *data; 356 struct net_device *dev = platform_get_drvdata(ofdev); 357 struct mscan_priv *priv = netdev_priv(dev); 358 359 match = of_match_device(mpc5xxx_can_table, &ofdev->dev); 360 data = match ? match->data : NULL; 361 362 unregister_mscandev(dev); 363 if (data && data->put_clock) 364 data->put_clock(ofdev); 365 iounmap(priv->reg_base); 366 irq_dispose_mapping(dev->irq); 367 free_candev(dev); 368 } 369 370 #ifdef CONFIG_PM 371 static struct mscan_regs saved_regs; 372 static int mpc5xxx_can_suspend(struct platform_device *ofdev, pm_message_t state) 373 { 374 struct net_device *dev = platform_get_drvdata(ofdev); 375 struct mscan_priv *priv = netdev_priv(dev); 376 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base; 377 378 _memcpy_fromio(&saved_regs, regs, sizeof(*regs)); 379 380 return 0; 381 } 382 383 static int mpc5xxx_can_resume(struct platform_device *ofdev) 384 { 385 struct net_device *dev = platform_get_drvdata(ofdev); 386 struct mscan_priv *priv = netdev_priv(dev); 387 struct mscan_regs *regs = (struct mscan_regs *)priv->reg_base; 388 389 regs->canctl0 |= MSCAN_INITRQ; 390 while (!(regs->canctl1 & MSCAN_INITAK)) 391 udelay(10); 392 393 regs->canctl1 = saved_regs.canctl1; 394 regs->canbtr0 = saved_regs.canbtr0; 395 regs->canbtr1 = saved_regs.canbtr1; 396 regs->canidac = saved_regs.canidac; 397 398 /* restore masks, buffers etc. */ 399 _memcpy_toio(®s->canidar1_0, (void *)&saved_regs.canidar1_0, 400 sizeof(*regs) - offsetof(struct mscan_regs, canidar1_0)); 401 402 regs->canctl0 &= ~MSCAN_INITRQ; 403 regs->cantbsel = saved_regs.cantbsel; 404 regs->canrier = saved_regs.canrier; 405 regs->cantier = saved_regs.cantier; 406 regs->canctl0 = saved_regs.canctl0; 407 408 return 0; 409 } 410 #endif 411 412 static const struct mpc5xxx_can_data mpc5200_can_data = { 413 .type = MSCAN_TYPE_MPC5200, 414 .get_clock = mpc52xx_can_get_clock, 415 /* .put_clock not applicable */ 416 }; 417 418 static const struct mpc5xxx_can_data mpc5121_can_data = { 419 .type = MSCAN_TYPE_MPC5121, 420 .get_clock = mpc512x_can_get_clock, 421 .put_clock = mpc512x_can_put_clock, 422 }; 423 424 static const struct of_device_id mpc5xxx_can_table[] = { 425 { .compatible = "fsl,mpc5200-mscan", .data = &mpc5200_can_data, }, 426 /* Note that only MPC5121 Rev. 2 (and later) is supported */ 427 { .compatible = "fsl,mpc5121-mscan", .data = &mpc5121_can_data, }, 428 {}, 429 }; 430 MODULE_DEVICE_TABLE(of, mpc5xxx_can_table); 431 432 static struct platform_driver mpc5xxx_can_driver = { 433 .driver = { 434 .name = "mpc5xxx_can", 435 .of_match_table = mpc5xxx_can_table, 436 }, 437 .probe = mpc5xxx_can_probe, 438 .remove_new = mpc5xxx_can_remove, 439 #ifdef CONFIG_PM 440 .suspend = mpc5xxx_can_suspend, 441 .resume = mpc5xxx_can_resume, 442 #endif 443 }; 444 445 module_platform_driver(mpc5xxx_can_driver); 446 447 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 448 MODULE_DESCRIPTION("Freescale MPC5xxx CAN driver"); 449 MODULE_LICENSE("GPL v2"); 450