3  * RSB (Reduced Serial Bus) driver.
7  * The RSB controller looks like an SMBus controller which only supports
24  * RSB section of Allwinner's A80 user manual, which can be found at
49 #include <linux/sunxi-rsb.h>
52 /* RSB registers */
61 #define RSB_CMD		0x2c	/* RSB Command */
112 #define RSB_CTRL_NAME			"sunxi-rsb"
196  * sunxi_rsb_device_create() - allocate and add an RSB device
197  * @rsb:	RSB controller
198  * @node:	RSB slave device node
199  * @hwaddr:	RSB slave hardware address
200  * @rtaddr:	RSB slave runtime address
202 static struct sunxi_rsb_device *sunxi_rsb_device_create(struct sunxi_rsb *rsb,  in sunxi_rsb_device_create()  argument
212 	rdev->rsb = rsb;  in sunxi_rsb_device_create()
216 	rdev->dev.parent = rsb->dev;  in sunxi_rsb_device_create()
240  * sunxi_rsb_device_unregister(): unregister an RSB device
259  * sunxi_rsb_driver_register() - Register device driver with RSB core
262  * This API will register the client driver with the RSB framework.
273 static int _sunxi_rsb_run_xfer(struct sunxi_rsb *rsb)  in _sunxi_rsb_run_xfer()  argument
278 	if (readl(rsb->regs + RSB_CTRL) & RSB_CTRL_START_TRANS) {  in _sunxi_rsb_run_xfer()
279 		dev_dbg(rsb->dev, "RSB transfer still in progress\n");  in _sunxi_rsb_run_xfer()
283 	reinit_completion(&rsb->complete);  in _sunxi_rsb_run_xfer()
286 	writel(int_mask, rsb->regs + RSB_INTE);  in _sunxi_rsb_run_xfer()
288 	       rsb->regs + RSB_CTRL);  in _sunxi_rsb_run_xfer()
291 		timeout = readl_poll_timeout_atomic(rsb->regs + RSB_INTS,  in _sunxi_rsb_run_xfer()
294 		writel(status, rsb->regs + RSB_INTS);  in _sunxi_rsb_run_xfer()
296 		timeout = !wait_for_completion_io_timeout(&rsb->complete,  in _sunxi_rsb_run_xfer()
298 		status = rsb->status;  in _sunxi_rsb_run_xfer()
302 		dev_dbg(rsb->dev, "RSB timeout\n");  in _sunxi_rsb_run_xfer()
305 		writel(RSB_CTRL_ABORT_TRANS, rsb->regs + RSB_CTRL);  in _sunxi_rsb_run_xfer()
308 		writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS);  in _sunxi_rsb_run_xfer()
314 		dev_dbg(rsb->dev, "RSB busy\n");  in _sunxi_rsb_run_xfer()
320 			dev_dbg(rsb->dev, "RSB slave nack\n");  in _sunxi_rsb_run_xfer()
325 			dev_dbg(rsb->dev, "RSB transfer data error\n");  in _sunxi_rsb_run_xfer()
333 static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,  in sunxi_rsb_read()  argument
353 		dev_err(rsb->dev, "Invalid access width: %zd\n", len);  in sunxi_rsb_read()
357 	ret = pm_runtime_resume_and_get(rsb->dev);  in sunxi_rsb_read()
361 	mutex_lock(&rsb->lock);  in sunxi_rsb_read()
363 	writel(addr, rsb->regs + RSB_ADDR);  in sunxi_rsb_read()
364 	writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR);  in sunxi_rsb_read()
365 	writel(cmd, rsb->regs + RSB_CMD);  in sunxi_rsb_read()
367 	ret = _sunxi_rsb_run_xfer(rsb);  in sunxi_rsb_read()
371 	*buf = readl(rsb->regs + RSB_DATA) & GENMASK(len * 8 - 1, 0);  in sunxi_rsb_read()
374 	mutex_unlock(&rsb->lock);  in sunxi_rsb_read()
376 	pm_runtime_mark_last_busy(rsb->dev);  in sunxi_rsb_read()
377 	pm_runtime_put_autosuspend(rsb->dev);  in sunxi_rsb_read()
382 static int sunxi_rsb_write(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr,  in sunxi_rsb_write()  argument
402 		dev_err(rsb->dev, "Invalid access width: %zd\n", len);  in sunxi_rsb_write()
406 	ret = pm_runtime_resume_and_get(rsb->dev);  in sunxi_rsb_write()
410 	mutex_lock(&rsb->lock);  in sunxi_rsb_write()
412 	writel(addr, rsb->regs + RSB_ADDR);  in sunxi_rsb_write()
413 	writel(RSB_DAR_RTA(rtaddr), rsb->regs + RSB_DAR);  in sunxi_rsb_write()
414 	writel(*buf, rsb->regs + RSB_DATA);  in sunxi_rsb_write()
415 	writel(cmd, rsb->regs + RSB_CMD);  in sunxi_rsb_write()
416 	ret = _sunxi_rsb_run_xfer(rsb);  in sunxi_rsb_write()
418 	mutex_unlock(&rsb->lock);  in sunxi_rsb_write()
420 	pm_runtime_mark_last_busy(rsb->dev);  in sunxi_rsb_write()
421 	pm_runtime_put_autosuspend(rsb->dev);  in sunxi_rsb_write()
426 /* RSB regmap functions */
441 	return sunxi_rsb_read(rdev->rsb, rdev->rtaddr, reg, val, ctx->size);  in regmap_sunxi_rsb_reg_read()
450 	return sunxi_rsb_write(rdev->rsb, rdev->rtaddr, reg, &val, ctx->size);  in regmap_sunxi_rsb_reg_write()
507 /* RSB controller driver functions */
510 	struct sunxi_rsb *rsb = dev_id;  in sunxi_rsb_irq()  local
513 	status = readl(rsb->regs + RSB_INTS);  in sunxi_rsb_irq()
514 	rsb->status = status;  in sunxi_rsb_irq()
519 	writel(status, rsb->regs + RSB_INTS);  in sunxi_rsb_irq()
521 	complete(&rsb->complete);  in sunxi_rsb_irq()
526 static int sunxi_rsb_init_device_mode(struct sunxi_rsb *rsb)  in sunxi_rsb_init_device_mode()  argument
533 	       RSB_DMCR_MODE_REG | RSB_DMCR_DEV_ADDR, rsb->regs + RSB_DMCR);  in sunxi_rsb_init_device_mode()
535 	readl_poll_timeout(rsb->regs + RSB_DMCR, reg,  in sunxi_rsb_init_device_mode()
541 	writel(readl(rsb->regs + RSB_INTS), rsb->regs + RSB_INTS);  in sunxi_rsb_init_device_mode()
553  * No designs with 2 RSB slave devices sharing identical hardware
580 static int of_rsb_register_devices(struct sunxi_rsb *rsb)  in of_rsb_register_devices()  argument
582 	struct device *dev = rsb->dev;  in of_rsb_register_devices()
616 		writel(RSB_CMD_STRA, rsb->regs + RSB_CMD);  in of_rsb_register_devices()
618 		       rsb->regs + RSB_DAR);  in of_rsb_register_devices()
621 		ret = _sunxi_rsb_run_xfer(rsb);  in of_rsb_register_devices()
641 		rdev = sunxi_rsb_device_create(rsb, child, hwaddr, rtaddr);  in of_rsb_register_devices()
650 static int sunxi_rsb_hw_init(struct sunxi_rsb *rsb)  in sunxi_rsb_hw_init()  argument
652 	struct device *dev = rsb->dev;  in sunxi_rsb_hw_init()
657 	ret = clk_prepare_enable(rsb->clk);  in sunxi_rsb_hw_init()
663 	ret = reset_control_deassert(rsb->rstc);  in sunxi_rsb_hw_init()
670 	writel(RSB_CTRL_SOFT_RST, rsb->regs + RSB_CTRL);  in sunxi_rsb_hw_init()
671 	readl_poll_timeout(rsb->regs + RSB_CTRL, reg,  in sunxi_rsb_hw_init()
681 	p_clk_freq = clk_get_rate(rsb->clk);  in sunxi_rsb_hw_init()
682 	clk_div = p_clk_freq / rsb->clk_freq / 2;  in sunxi_rsb_hw_init()
692 	dev_info(dev, "RSB running at %lu Hz\n", p_clk_freq / clk_div / 2);  in sunxi_rsb_hw_init()
694 	       rsb->regs + RSB_CCR);  in sunxi_rsb_hw_init()
699 	clk_disable_unprepare(rsb->clk);  in sunxi_rsb_hw_init()
704 static void sunxi_rsb_hw_exit(struct sunxi_rsb *rsb)  in sunxi_rsb_hw_exit()  argument
706 	reset_control_assert(rsb->rstc);  in sunxi_rsb_hw_exit()
709 	if (!pm_runtime_status_suspended(rsb->dev))  in sunxi_rsb_hw_exit()
710 		clk_disable_unprepare(rsb->clk);  in sunxi_rsb_hw_exit()
715 	struct sunxi_rsb *rsb = dev_get_drvdata(dev);  in sunxi_rsb_runtime_suspend()  local
717 	clk_disable_unprepare(rsb->clk);  in sunxi_rsb_runtime_suspend()
724 	struct sunxi_rsb *rsb = dev_get_drvdata(dev);  in sunxi_rsb_runtime_resume()  local
726 	return clk_prepare_enable(rsb->clk);  in sunxi_rsb_runtime_resume()
731 	struct sunxi_rsb *rsb = dev_get_drvdata(dev);  in sunxi_rsb_suspend()  local
733 	sunxi_rsb_hw_exit(rsb);  in sunxi_rsb_suspend()
740 	struct sunxi_rsb *rsb = dev_get_drvdata(dev);  in sunxi_rsb_resume()  local
742 	return sunxi_rsb_hw_init(rsb);  in sunxi_rsb_resume()
749 	struct sunxi_rsb *rsb;  in sunxi_rsb_probe()  local
759 	rsb = devm_kzalloc(dev, sizeof(*rsb), GFP_KERNEL);  in sunxi_rsb_probe()
760 	if (!rsb)  in sunxi_rsb_probe()
763 	rsb->dev = dev;  in sunxi_rsb_probe()
764 	rsb->clk_freq = clk_freq;  in sunxi_rsb_probe()
765 	platform_set_drvdata(pdev, rsb);  in sunxi_rsb_probe()
766 	rsb->regs = devm_platform_ioremap_resource(pdev, 0);  in sunxi_rsb_probe()
767 	if (IS_ERR(rsb->regs))  in sunxi_rsb_probe()
768 		return PTR_ERR(rsb->regs);  in sunxi_rsb_probe()
774 	rsb->clk = devm_clk_get(dev, NULL);  in sunxi_rsb_probe()
775 	if (IS_ERR(rsb->clk))  in sunxi_rsb_probe()
776 		return dev_err_probe(dev, PTR_ERR(rsb->clk),  in sunxi_rsb_probe()
779 	rsb->rstc = devm_reset_control_get(dev, NULL);  in sunxi_rsb_probe()
780 	if (IS_ERR(rsb->rstc))  in sunxi_rsb_probe()
781 		return dev_err_probe(dev, PTR_ERR(rsb->rstc),  in sunxi_rsb_probe()
784 	init_completion(&rsb->complete);  in sunxi_rsb_probe()
785 	mutex_init(&rsb->lock);  in sunxi_rsb_probe()
787 	ret = devm_request_irq(dev, irq, sunxi_rsb_irq, 0, RSB_CTRL_NAME, rsb);  in sunxi_rsb_probe()
792 	ret = sunxi_rsb_hw_init(rsb);  in sunxi_rsb_probe()
796 	/* initialize all devices on the bus into RSB mode */  in sunxi_rsb_probe()
797 	ret = sunxi_rsb_init_device_mode(rsb);  in sunxi_rsb_probe()
807 	of_rsb_register_devices(rsb);  in sunxi_rsb_probe()
814 	struct sunxi_rsb *rsb = platform_get_drvdata(pdev);  in sunxi_rsb_remove()  local
816 	device_for_each_child(rsb->dev, NULL, sunxi_rsb_remove_devices);  in sunxi_rsb_remove()
818 	sunxi_rsb_hw_exit(rsb);  in sunxi_rsb_remove()
828 	{ .compatible = "allwinner,sun8i-a23-rsb" },