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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * RSB (Reduced Serial Bus) driver.4 *5 * Author: Chen-Yu Tsai <wens@csie.org>6 *7 * The RSB controller looks like an SMBus controller which only supports8 * byte and word data transfers. But, it differs from standard SMBus9 * protocol on several aspects:10 * - it uses addresses set at runtime to address slaves. Runtime addresses11 * are sent to slaves using their 12bit hardware addresses. Up to 1512 * runtime addresses are available.13 * - it adds a parity bit every 8bits of data and address for read and14 * write accesses; this replaces the ack bit15 * - only one read access is required to read a byte (instead of a write16 * followed by a read access in standard SMBus protocol)17 * - there's no Ack bit after each read access18 *19 * This means this bus cannot be used to interface with standard SMBus20 * devices. Devices known to support this interface include the AXP223,21 * AXP809, and AXP806 PMICs, and the AC100 audio codec, all from X-Powers.22 *23 * A description of the operation and wire protocol can be found in the24 * RSB section of Allwinner's A80 user manual, which can be found at25 *26 * https://github.com/allwinner-zh/documents/tree/master/A8027 *28 * This document is officially released by Allwinner.29 *30 * This driver is based on i2c-sun6i-p2wi.c, the P2WI bus driver.31 */32 33#include <linux/clk.h>34#include <linux/clk/clk-conf.h>35#include <linux/device.h>36#include <linux/interrupt.h>37#include <linux/io.h>38#include <linux/iopoll.h>39#include <linux/module.h>40#include <linux/of.h>41#include <linux/of_irq.h>42#include <linux/of_device.h>43#include <linux/platform_device.h>44#include <linux/pm.h>45#include <linux/pm_runtime.h>46#include <linux/regmap.h>47#include <linux/reset.h>48#include <linux/slab.h>49#include <linux/sunxi-rsb.h>50#include <linux/types.h>51 52/* RSB registers */53#define RSB_CTRL 0x0 /* Global control */54#define RSB_CCR 0x4 /* Clock control */55#define RSB_INTE 0x8 /* Interrupt controls */56#define RSB_INTS 0xc /* Interrupt status */57#define RSB_ADDR 0x10 /* Address to send with read/write command */58#define RSB_DATA 0x1c /* Data to read/write */59#define RSB_LCR 0x24 /* Line control */60#define RSB_DMCR 0x28 /* Device mode (init) control */61#define RSB_CMD 0x2c /* RSB Command */62#define RSB_DAR 0x30 /* Device address / runtime address */63 64/* CTRL fields */65#define RSB_CTRL_START_TRANS BIT(7)66#define RSB_CTRL_ABORT_TRANS BIT(6)67#define RSB_CTRL_GLOBAL_INT_ENB BIT(1)68#define RSB_CTRL_SOFT_RST BIT(0)69 70/* CLK CTRL fields */71#define RSB_CCR_SDA_OUT_DELAY(v) (((v) & 0x7) << 8)72#define RSB_CCR_MAX_CLK_DIV 0xff73#define RSB_CCR_CLK_DIV(v) ((v) & RSB_CCR_MAX_CLK_DIV)74 75/* STATUS fields */76#define RSB_INTS_TRANS_ERR_ACK BIT(16)77#define RSB_INTS_TRANS_ERR_DATA_BIT(v) (((v) >> 8) & 0xf)78#define RSB_INTS_TRANS_ERR_DATA GENMASK(11, 8)79#define RSB_INTS_LOAD_BSY BIT(2)80#define RSB_INTS_TRANS_ERR BIT(1)81#define RSB_INTS_TRANS_OVER BIT(0)82 83/* LINE CTRL fields*/84#define RSB_LCR_SCL_STATE BIT(5)85#define RSB_LCR_SDA_STATE BIT(4)86#define RSB_LCR_SCL_CTL BIT(3)87#define RSB_LCR_SCL_CTL_EN BIT(2)88#define RSB_LCR_SDA_CTL BIT(1)89#define RSB_LCR_SDA_CTL_EN BIT(0)90 91/* DEVICE MODE CTRL field values */92#define RSB_DMCR_DEVICE_START BIT(31)93#define RSB_DMCR_MODE_DATA (0x7c << 16)94#define RSB_DMCR_MODE_REG (0x3e << 8)95#define RSB_DMCR_DEV_ADDR 0x0096 97/* CMD values */98#define RSB_CMD_RD8 0x8b99#define RSB_CMD_RD16 0x9c100#define RSB_CMD_RD32 0xa6101#define RSB_CMD_WR8 0x4e102#define RSB_CMD_WR16 0x59103#define RSB_CMD_WR32 0x63104#define RSB_CMD_STRA 0xe8105 106/* DAR fields */107#define RSB_DAR_RTA(v) (((v) & 0xff) << 16)108#define RSB_DAR_DA(v) ((v) & 0xffff)109 110#define RSB_MAX_FREQ 20000000111 112#define RSB_CTRL_NAME "sunxi-rsb"113 114struct sunxi_rsb_addr_map {115 u16 hwaddr;116 u8 rtaddr;117};118 119struct sunxi_rsb {120 struct device *dev;121 void __iomem *regs;122 struct clk *clk;123 struct reset_control *rstc;124 struct completion complete;125 struct mutex lock;126 unsigned int status;127 u32 clk_freq;128};129 130/* bus / slave device related functions */131static const struct bus_type sunxi_rsb_bus;132 133static int sunxi_rsb_device_match(struct device *dev, const struct device_driver *drv)134{135 return of_driver_match_device(dev, drv);136}137 138static int sunxi_rsb_device_probe(struct device *dev)139{140 const struct sunxi_rsb_driver *drv = to_sunxi_rsb_driver(dev->driver);141 struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);142 int ret;143 144 if (!drv->probe)145 return -ENODEV;146 147 if (!rdev->irq) {148 int irq = -ENOENT;149 150 if (dev->of_node)151 irq = of_irq_get(dev->of_node, 0);152 153 if (irq == -EPROBE_DEFER)154 return irq;155 if (irq < 0)156 irq = 0;157 158 rdev->irq = irq;159 }160 161 ret = of_clk_set_defaults(dev->of_node, false);162 if (ret < 0)163 return ret;164 165 return drv->probe(rdev);166}167 168static void sunxi_rsb_device_remove(struct device *dev)169{170 const struct sunxi_rsb_driver *drv = to_sunxi_rsb_driver(dev->driver);171 172 drv->remove(to_sunxi_rsb_device(dev));173}174 175static int sunxi_rsb_device_modalias(const struct device *dev, struct kobj_uevent_env *env)176{177 return of_device_uevent_modalias(dev, env);178}179 180static const struct bus_type sunxi_rsb_bus = {181 .name = RSB_CTRL_NAME,182 .match = sunxi_rsb_device_match,183 .probe = sunxi_rsb_device_probe,184 .remove = sunxi_rsb_device_remove,185 .uevent = sunxi_rsb_device_modalias,186};187 188static void sunxi_rsb_dev_release(struct device *dev)189{190 struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);191 192 kfree(rdev);193}194 195/**196 * sunxi_rsb_device_create() - allocate and add an RSB device197 * @rsb: RSB controller198 * @node: RSB slave device node199 * @hwaddr: RSB slave hardware address200 * @rtaddr: RSB slave runtime address201 */202static struct sunxi_rsb_device *sunxi_rsb_device_create(struct sunxi_rsb *rsb,203 struct device_node *node, u16 hwaddr, u8 rtaddr)204{205 int err;206 struct sunxi_rsb_device *rdev;207 208 rdev = kzalloc(sizeof(*rdev), GFP_KERNEL);209 if (!rdev)210 return ERR_PTR(-ENOMEM);211 212 rdev->rsb = rsb;213 rdev->hwaddr = hwaddr;214 rdev->rtaddr = rtaddr;215 rdev->dev.bus = &sunxi_rsb_bus;216 rdev->dev.parent = rsb->dev;217 rdev->dev.of_node = node;218 rdev->dev.release = sunxi_rsb_dev_release;219 220 dev_set_name(&rdev->dev, "%s-%x", RSB_CTRL_NAME, hwaddr);221 222 err = device_register(&rdev->dev);223 if (err < 0) {224 dev_err(&rdev->dev, "Can't add %s, status %d\n",225 dev_name(&rdev->dev), err);226 goto err_device_add;227 }228 229 dev_dbg(&rdev->dev, "device %s registered\n", dev_name(&rdev->dev));230 231 return rdev;232 233err_device_add:234 put_device(&rdev->dev);235 236 return ERR_PTR(err);237}238 239/**240 * sunxi_rsb_device_unregister(): unregister an RSB device241 * @rdev: rsb_device to be removed242 */243static void sunxi_rsb_device_unregister(struct sunxi_rsb_device *rdev)244{245 device_unregister(&rdev->dev);246}247 248static int sunxi_rsb_remove_devices(struct device *dev, void *data)249{250 struct sunxi_rsb_device *rdev = to_sunxi_rsb_device(dev);251 252 if (dev->bus == &sunxi_rsb_bus)253 sunxi_rsb_device_unregister(rdev);254 255 return 0;256}257 258/**259 * sunxi_rsb_driver_register() - Register device driver with RSB core260 * @rdrv: device driver to be associated with slave-device.261 *262 * This API will register the client driver with the RSB framework.263 * It is typically called from the driver's module-init function.264 */265int sunxi_rsb_driver_register(struct sunxi_rsb_driver *rdrv)266{267 rdrv->driver.bus = &sunxi_rsb_bus;268 return driver_register(&rdrv->driver);269}270EXPORT_SYMBOL_GPL(sunxi_rsb_driver_register);271 272/* common code that starts a transfer */273static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb)274{275 u32 int_mask, status;276 bool timeout;277 278 if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) {279 dev_dbg(rsb->dev, "RSB transfer still in progress\n");280 return -EBUSY;281 }282 283 reinit_completion(&rsb->complete);284 285 int_mask = RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR | RSB_INTS_TRANS_OVER;286 writel(int_mask, rsb->regs + RSB_INTE);287 writel(RSB_CTRL_START_TRANS | RSB_CTRL_GLOBAL_INT_ENB,288 rsb->regs + RSB_CTRL);289 290 if (irqs_disabled()) {291 timeout = readl_poll_timeout_atomic(rsb->regs + RSB_INTS,292 status, (status & int_mask),293 10, 100000);294 writel(status, rsb->regs + RSB_INTS);295 } else {296 timeout = !wait_for_completion_io_timeout(&rsb->complete,297 msecs_to_jiffies(100));298 status = rsb->status;299 }300 301 if (timeout) {302 dev_dbg(rsb->dev, "RSB timeout\n");303 304 /* abort the transfer */305 writel(RSB_CTRL_ABORT_TRANS, rsb->regs + RSB_CTRL);306 307 /* clear any interrupt flags */308 writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS);309 310 return -ETIMEDOUT;311 }312 313 if (status & RSB_INTS_LOAD_BSY) {314 dev_dbg(rsb->dev, "RSB busy\n");315 return -EBUSY;316 }317 318 if (status & RSB_INTS_TRANS_ERR) {319 if (status & RSB_INTS_TRANS_ERR_ACK) {320 dev_dbg(rsb->dev, "RSB slave nack\n");321 return -EINVAL;322 }323 324 if (status & RSB_INTS_TRANS_ERR_DATA) {325 dev_dbg(rsb->dev, "RSB transfer data error\n");326 return -EIO;327 }328 }329 330 return 0;331}332 333static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,334 u32 *buf, size_t len)335{336 u32 cmd;337 int ret;338 339 if (!buf)340 return -EINVAL;341 342 switch (len) {343 case 1:344 cmd = RSB_CMD_RD8;345 break;346 case 2:347 cmd = RSB_CMD_RD16;348 break;349 case 4:350 cmd = RSB_CMD_RD32;351 break;352 default:353 dev_err(rsb->dev, "Invalid access width: %zd\n", len);354 return -EINVAL;355 }356 357 ret = pm_runtime_resume_and_get(rsb->dev);358 if (ret)359 return ret;360 361 mutex_lock(&rsb->lock);362 363 writel(addr, rsb->regs + RSB_ADDR);364 writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR);365 writel(cmd, rsb->regs + RSB_CMD);366 367 ret = _sunxi_rsb_run_xfer(rsb);368 if (ret)369 goto unlock;370 371 *buf = readl(rsb->regs + RSB_DATA) & GENMASK(len * 8 - 1, 0);372 373unlock:374 mutex_unlock(&rsb->lock);375 376 pm_runtime_mark_last_busy(rsb->dev);377 pm_runtime_put_autosuspend(rsb->dev);378 379 return ret;380}381 382static int sunxi_rsb_write(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,383 const u32 *buf, size_t len)384{385 u32 cmd;386 int ret;387 388 if (!buf)389 return -EINVAL;390 391 switch (len) {392 case 1:393 cmd = RSB_CMD_WR8;394 break;395 case 2:396 cmd = RSB_CMD_WR16;397 break;398 case 4:399 cmd = RSB_CMD_WR32;400 break;401 default:402 dev_err(rsb->dev, "Invalid access width: %zd\n", len);403 return -EINVAL;404 }405 406 ret = pm_runtime_resume_and_get(rsb->dev);407 if (ret)408 return ret;409 410 mutex_lock(&rsb->lock);411 412 writel(addr, rsb->regs + RSB_ADDR);413 writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR);414 writel(*buf, rsb->regs + RSB_DATA);415 writel(cmd, rsb->regs + RSB_CMD);416 ret = _sunxi_rsb_run_xfer(rsb);417 418 mutex_unlock(&rsb->lock);419 420 pm_runtime_mark_last_busy(rsb->dev);421 pm_runtime_put_autosuspend(rsb->dev);422 423 return ret;424}425 426/* RSB regmap functions */427struct sunxi_rsb_ctx {428 struct sunxi_rsb_device *rdev;429 int size;430};431 432static int regmap_sunxi_rsb_reg_read(void *context, unsigned int reg,433 unsigned int *val)434{435 struct sunxi_rsb_ctx *ctx = context;436 struct sunxi_rsb_device *rdev = ctx->rdev;437 438 if (reg > 0xff)439 return -EINVAL;440 441 return sunxi_rsb_read(rdev->rsb, rdev->rtaddr, reg, val, ctx->size);442}443 444static int regmap_sunxi_rsb_reg_write(void *context, unsigned int reg,445 unsigned int val)446{447 struct sunxi_rsb_ctx *ctx = context;448 struct sunxi_rsb_device *rdev = ctx->rdev;449 450 return sunxi_rsb_write(rdev->rsb, rdev->rtaddr, reg, &val, ctx->size);451}452 453static void regmap_sunxi_rsb_free_ctx(void *context)454{455 struct sunxi_rsb_ctx *ctx = context;456 457 kfree(ctx);458}459 460static const struct regmap_bus regmap_sunxi_rsb = {461 .reg_write = regmap_sunxi_rsb_reg_write,462 .reg_read = regmap_sunxi_rsb_reg_read,463 .free_context = regmap_sunxi_rsb_free_ctx,464 .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,465 .val_format_endian_default = REGMAP_ENDIAN_NATIVE,466};467 468static struct sunxi_rsb_ctx *regmap_sunxi_rsb_init_ctx(struct sunxi_rsb_device *rdev,469 const struct regmap_config *config)470{471 struct sunxi_rsb_ctx *ctx;472 473 switch (config->val_bits) {474 case 8:475 case 16:476 case 32:477 break;478 default:479 return ERR_PTR(-EINVAL);480 }481 482 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);483 if (!ctx)484 return ERR_PTR(-ENOMEM);485 486 ctx->rdev = rdev;487 ctx->size = config->val_bits / 8;488 489 return ctx;490}491 492struct regmap *__devm_regmap_init_sunxi_rsb(struct sunxi_rsb_device *rdev,493 const struct regmap_config *config,494 struct lock_class_key *lock_key,495 const char *lock_name)496{497 struct sunxi_rsb_ctx *ctx = regmap_sunxi_rsb_init_ctx(rdev, config);498 499 if (IS_ERR(ctx))500 return ERR_CAST(ctx);501 502 return __devm_regmap_init(&rdev->dev, ®map_sunxi_rsb, ctx, config,503 lock_key, lock_name);504}505EXPORT_SYMBOL_GPL(__devm_regmap_init_sunxi_rsb);506 507/* RSB controller driver functions */508static irqreturn_t sunxi_rsb_irq(int irq, void *dev_id)509{510 struct sunxi_rsb *rsb = dev_id;511 u32 status;512 513 status = readl(rsb->regs + RSB_INTS);514 rsb->status = status;515 516 /* Clear interrupts */517 status &= (RSB_INTS_LOAD_BSY | RSB_INTS_TRANS_ERR |518 RSB_INTS_TRANS_OVER);519 writel(status, rsb->regs + RSB_INTS);520 521 complete(&rsb->complete);522 523 return IRQ_HANDLED;524}525 526static int sunxi_rsb_init_device_mode(struct sunxi_rsb *rsb)527{528 int ret = 0;529 u32 reg;530 531 /* send init sequence */532 writel(RSB_DMCR_DEVICE_START | RSB_DMCR_MODE_DATA |533 RSB_DMCR_MODE_REG | RSB_DMCR_DEV_ADDR, rsb->regs + RSB_DMCR);534 535 readl_poll_timeout(rsb->regs + RSB_DMCR, reg,536 !(reg & RSB_DMCR_DEVICE_START), 100, 250000);537 if (reg & RSB_DMCR_DEVICE_START)538 ret = -ETIMEDOUT;539 540 /* clear interrupt status bits */541 writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS);542 543 return ret;544}545 546/*547 * There are 15 valid runtime addresses, though Allwinner typically548 * skips the first, for unknown reasons, and uses the following three.549 *550 * 0x17, 0x2d, 0x3a, 0x4e, 0x59, 0x63, 0x74, 0x8b,551 * 0x9c, 0xa6, 0xb1, 0xc5, 0xd2, 0xe8, 0xff552 *553 * No designs with 2 RSB slave devices sharing identical hardware554 * addresses on the same bus have been seen in the wild. All designs555 * use 0x2d for the primary PMIC, 0x3a for the secondary PMIC if556 * there is one, and 0x45 for peripheral ICs.557 *558 * The hardware does not seem to support re-setting runtime addresses.559 * Attempts to do so result in the slave devices returning a NACK.560 * Hence we just hardcode the mapping here, like Allwinner does.561 */562 563static const struct sunxi_rsb_addr_map sunxi_rsb_addr_maps[] = {564 { 0x3a3, 0x2d }, /* Primary PMIC: AXP223, AXP809, AXP81X, ... */565 { 0x745, 0x3a }, /* Secondary PMIC: AXP806, ... */566 { 0xe89, 0x4e }, /* Peripheral IC: AC100, ... */567};568 569static u8 sunxi_rsb_get_rtaddr(u16 hwaddr)570{571 int i;572 573 for (i = 0; i < ARRAY_SIZE(sunxi_rsb_addr_maps); i++)574 if (hwaddr == sunxi_rsb_addr_maps[i].hwaddr)575 return sunxi_rsb_addr_maps[i].rtaddr;576 577 return 0; /* 0 is an invalid runtime address */578}579 580static int of_rsb_register_devices(struct sunxi_rsb *rsb)581{582 struct device *dev = rsb->dev;583 struct device_node *child, *np = dev->of_node;584 u32 hwaddr;585 u8 rtaddr;586 int ret;587 588 if (!np)589 return -EINVAL;590 591 /* Runtime addresses for all slaves should be set first */592 for_each_available_child_of_node(np, child) {593 dev_dbg(dev, "setting child %pOF runtime address\n",594 child);595 596 ret = of_property_read_u32(child, "reg", &hwaddr);597 if (ret) {598 dev_err(dev, "%pOF: invalid 'reg' property: %d\n",599 child, ret);600 continue;601 }602 603 rtaddr = sunxi_rsb_get_rtaddr(hwaddr);604 if (!rtaddr) {605 dev_err(dev, "%pOF: unknown hardware device address\n",606 child);607 continue;608 }609 610 /*611 * Since no devices have been registered yet, we are the612 * only ones using the bus, we can skip locking the bus.613 */614 615 /* setup command parameters */616 writel(RSB_CMD_STRA, rsb->regs + RSB_CMD);617 writel(RSB_DAR_RTA(rtaddr) | RSB_DAR_DA(hwaddr),618 rsb->regs + RSB_DAR);619 620 /* send command */621 ret = _sunxi_rsb_run_xfer(rsb);622 if (ret)623 dev_warn(dev, "%pOF: set runtime address failed: %d\n",624 child, ret);625 }626 627 /* Then we start adding devices and probing them */628 for_each_available_child_of_node(np, child) {629 struct sunxi_rsb_device *rdev;630 631 dev_dbg(dev, "adding child %pOF\n", child);632 633 ret = of_property_read_u32(child, "reg", &hwaddr);634 if (ret)635 continue;636 637 rtaddr = sunxi_rsb_get_rtaddr(hwaddr);638 if (!rtaddr)639 continue;640 641 rdev = sunxi_rsb_device_create(rsb, child, hwaddr, rtaddr);642 if (IS_ERR(rdev))643 dev_err(dev, "failed to add child device %pOF: %ld\n",644 child, PTR_ERR(rdev));645 }646 647 return 0;648}649 650static int sunxi_rsb_hw_init(struct sunxi_rsb *rsb)651{652 struct device *dev = rsb->dev;653 unsigned long p_clk_freq;654 u32 clk_delay, reg;655 int clk_div, ret;656 657 ret = clk_prepare_enable(rsb->clk);658 if (ret) {659 dev_err(dev, "failed to enable clk: %d\n", ret);660 return ret;661 }662 663 ret = reset_control_deassert(rsb->rstc);664 if (ret) {665 dev_err(dev, "failed to deassert reset line: %d\n", ret);666 goto err_clk_disable;667 }668 669 /* reset the controller */670 writel(RSB_CTRL_SOFT_RST, rsb->regs + RSB_CTRL);671 readl_poll_timeout(rsb->regs + RSB_CTRL, reg,672 !(reg & RSB_CTRL_SOFT_RST), 1000, 100000);673 674 /*675 * Clock frequency and delay calculation code is from676 * Allwinner U-boot sources.677 *678 * From A83 user manual:679 * bus clock frequency = parent clock frequency / (2 * (divider + 1))680 */681 p_clk_freq = clk_get_rate(rsb->clk);682 clk_div = p_clk_freq / rsb->clk_freq / 2;683 if (!clk_div)684 clk_div = 1;685 else if (clk_div > RSB_CCR_MAX_CLK_DIV + 1)686 clk_div = RSB_CCR_MAX_CLK_DIV + 1;687 688 clk_delay = clk_div >> 1;689 if (!clk_delay)690 clk_delay = 1;691 692 dev_info(dev, "RSB running at %lu Hz\n", p_clk_freq / clk_div / 2);693 writel(RSB_CCR_SDA_OUT_DELAY(clk_delay) | RSB_CCR_CLK_DIV(clk_div - 1),694 rsb->regs + RSB_CCR);695 696 return 0;697 698err_clk_disable:699 clk_disable_unprepare(rsb->clk);700 701 return ret;702}703 704static void sunxi_rsb_hw_exit(struct sunxi_rsb *rsb)705{706 reset_control_assert(rsb->rstc);707 708 /* Keep the clock and PM reference counts consistent. */709 if (!pm_runtime_status_suspended(rsb->dev))710 clk_disable_unprepare(rsb->clk);711}712 713static int __maybe_unused sunxi_rsb_runtime_suspend(struct device *dev)714{715 struct sunxi_rsb *rsb = dev_get_drvdata(dev);716 717 clk_disable_unprepare(rsb->clk);718 719 return 0;720}721 722static int __maybe_unused sunxi_rsb_runtime_resume(struct device *dev)723{724 struct sunxi_rsb *rsb = dev_get_drvdata(dev);725 726 return clk_prepare_enable(rsb->clk);727}728 729static int __maybe_unused sunxi_rsb_suspend(struct device *dev)730{731 struct sunxi_rsb *rsb = dev_get_drvdata(dev);732 733 sunxi_rsb_hw_exit(rsb);734 735 return 0;736}737 738static int __maybe_unused sunxi_rsb_resume(struct device *dev)739{740 struct sunxi_rsb *rsb = dev_get_drvdata(dev);741 742 return sunxi_rsb_hw_init(rsb);743}744 745static int sunxi_rsb_probe(struct platform_device *pdev)746{747 struct device *dev = &pdev->dev;748 struct device_node *np = dev->of_node;749 struct sunxi_rsb *rsb;750 u32 clk_freq = 3000000;751 int irq, ret;752 753 of_property_read_u32(np, "clock-frequency", &clk_freq);754 if (clk_freq > RSB_MAX_FREQ)755 return dev_err_probe(dev, -EINVAL,756 "clock-frequency (%u Hz) is too high (max = 20MHz)\n",757 clk_freq);758 759 rsb = devm_kzalloc(dev, sizeof(*rsb), GFP_KERNEL);760 if (!rsb)761 return -ENOMEM;762 763 rsb->dev = dev;764 rsb->clk_freq = clk_freq;765 platform_set_drvdata(pdev, rsb);766 rsb->regs = devm_platform_ioremap_resource(pdev, 0);767 if (IS_ERR(rsb->regs))768 return PTR_ERR(rsb->regs);769 770 irq = platform_get_irq(pdev, 0);771 if (irq < 0)772 return irq;773 774 rsb->clk = devm_clk_get(dev, NULL);775 if (IS_ERR(rsb->clk))776 return dev_err_probe(dev, PTR_ERR(rsb->clk),777 "failed to retrieve clk\n");778 779 rsb->rstc = devm_reset_control_get(dev, NULL);780 if (IS_ERR(rsb->rstc))781 return dev_err_probe(dev, PTR_ERR(rsb->rstc),782 "failed to retrieve reset controller\n");783 784 init_completion(&rsb->complete);785 mutex_init(&rsb->lock);786 787 ret = devm_request_irq(dev, irq, sunxi_rsb_irq, 0, RSB_CTRL_NAME, rsb);788 if (ret)789 return dev_err_probe(dev, ret,790 "can't register interrupt handler irq %d\n", irq);791 792 ret = sunxi_rsb_hw_init(rsb);793 if (ret)794 return ret;795 796 /* initialize all devices on the bus into RSB mode */797 ret = sunxi_rsb_init_device_mode(rsb);798 if (ret)799 dev_warn(dev, "Initialize device mode failed: %d\n", ret);800 801 pm_suspend_ignore_children(dev, true);802 pm_runtime_set_active(dev);803 pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);804 pm_runtime_use_autosuspend(dev);805 pm_runtime_enable(dev);806 807 of_rsb_register_devices(rsb);808 809 return 0;810}811 812static void sunxi_rsb_remove(struct platform_device *pdev)813{814 struct sunxi_rsb *rsb = platform_get_drvdata(pdev);815 816 device_for_each_child(rsb->dev, NULL, sunxi_rsb_remove_devices);817 pm_runtime_disable(&pdev->dev);818 sunxi_rsb_hw_exit(rsb);819}820 821static const struct dev_pm_ops sunxi_rsb_dev_pm_ops = {822 SET_RUNTIME_PM_OPS(sunxi_rsb_runtime_suspend,823 sunxi_rsb_runtime_resume, NULL)824 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(sunxi_rsb_suspend, sunxi_rsb_resume)825};826 827static const struct of_device_id sunxi_rsb_of_match_table[] = {828 { .compatible = "allwinner,sun8i-a23-rsb" },829 {}830};831MODULE_DEVICE_TABLE(of, sunxi_rsb_of_match_table);832 833static struct platform_driver sunxi_rsb_driver = {834 .probe = sunxi_rsb_probe,835 .remove_new = sunxi_rsb_remove,836 .driver = {837 .name = RSB_CTRL_NAME,838 .of_match_table = sunxi_rsb_of_match_table,839 .pm = &sunxi_rsb_dev_pm_ops,840 },841};842 843static int __init sunxi_rsb_init(void)844{845 int ret;846 847 ret = bus_register(&sunxi_rsb_bus);848 if (ret) {849 pr_err("failed to register sunxi sunxi_rsb bus: %d\n", ret);850 return ret;851 }852 853 ret = platform_driver_register(&sunxi_rsb_driver);854 if (ret) {855 bus_unregister(&sunxi_rsb_bus);856 return ret;857 }858 859 return 0;860}861module_init(sunxi_rsb_init);862 863static void __exit sunxi_rsb_exit(void)864{865 platform_driver_unregister(&sunxi_rsb_driver);866 bus_unregister(&sunxi_rsb_bus);867}868module_exit(sunxi_rsb_exit);869 870MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");871MODULE_DESCRIPTION("Allwinner sunXi Reduced Serial Bus controller driver");872MODULE_LICENSE("GPL v2");873