[mirror_ubuntu-hirsute-kernel.git] / drivers / bus / omap-ocp2scp.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * omap-ocp2scp.c - transform ocp interface protocol to scp protocol
 *
 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
 * Author: Kishon Vijay Abraham I <kishon@ti.com>
 */

#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/of_platform.h>

#define OCP2SCP_TIMING 0x18
#define SYNC2_MASK 0xf

static int ocp2scp_remove_devices(struct device *dev, void *c)
{
	struct platform_device *pdev = to_platform_device(dev);

	platform_device_unregister(pdev);

	return 0;
}

static int omap_ocp2scp_probe(struct platform_device *pdev)
{
	int ret;
	u32 reg;
	void __iomem *regs;
	struct resource *res;
	struct device_node *np = pdev->dev.of_node;

	if (np) {
		ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
		if (ret) {
			dev_err(&pdev->dev,
			    "failed to add resources for ocp2scp child\n");
			goto err0;
		}
	}

	pm_runtime_enable(&pdev->dev);
	/*
	 * As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf
	 * under section 26.3.2.2, table 26-26 OCP2SCP TIMING Caution;
	 * As per OMAP4430 TRM: http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf
	 * under section 23.12.6.2.2 , Table 23-1213 OCP2SCP TIMING Caution;
	 * As per OMAP4460 TRM: http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf
	 * under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution;
	 * As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu249
	 * under section 27.3.2.2, Table 27-27 OCP2SCP TIMING Caution;
	 *
	 * Read path of OCP2SCP is not working properly due to low reset value
	 * of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more.
	 */
	if (!of_device_is_compatible(np, "ti,am437x-ocp2scp")) {
		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		regs = devm_ioremap_resource(&pdev->dev, res);
		if (IS_ERR(regs)) {
			ret = PTR_ERR(regs);
			goto err1;
		}

		pm_runtime_get_sync(&pdev->dev);
		reg = readl_relaxed(regs + OCP2SCP_TIMING);
		reg &= ~(SYNC2_MASK);
		reg |= 0x6;
		writel_relaxed(reg, regs + OCP2SCP_TIMING);
		pm_runtime_put_sync(&pdev->dev);
	}

	return 0;

err1:
	pm_runtime_disable(&pdev->dev);

err0:
	device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);

	return ret;
}

static int omap_ocp2scp_remove(struct platform_device *pdev)
{
	pm_runtime_disable(&pdev->dev);
	device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);

	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id omap_ocp2scp_id_table[] = {
	{ .compatible = "ti,omap-ocp2scp" },
	{ .compatible = "ti,am437x-ocp2scp" },
	{}
};
MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table);
#endif

static struct platform_driver omap_ocp2scp_driver = {
	.probe		= omap_ocp2scp_probe,
	.remove		= omap_ocp2scp_remove,
	.driver		= {
		.name	= "omap-ocp2scp",
		.of_match_table = of_match_ptr(omap_ocp2scp_id_table),
	},
};

module_platform_driver(omap_ocp2scp_driver);

MODULE_ALIAS("platform:omap-ocp2scp");
MODULE_AUTHOR("Texas Instruments Inc.");
MODULE_DESCRIPTION("OMAP OCP2SCP driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
c942fddf	1	// SPDX-License-Identifier: GPL-2.0-or-later
26a84b3e KVA	2	/*
	3	* omap-ocp2scp.c - transform ocp interface protocol to scp protocol
	4	*
	5	* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
26a84b3e	6	* Author: Kishon Vijay Abraham I <kishon@ti.com>
26a84b3e KVA	7	*/
26a84b3e KVA	8
cdf61240	9	#include <linux/io.h>
26a84b3e KVA	10	#include <linux/module.h>
	11	#include <linux/platform_device.h>
	12	#include <linux/err.h>
	13	#include <linux/pm_runtime.h>
	14	#include <linux/of.h>
	15	#include <linux/of_platform.h>
	16
cdf61240 KVA	17	#define OCP2SCP_TIMING 0x18
	18	#define SYNC2_MASK 0xf
	19
26a84b3e KVA	20	static int ocp2scp_remove_devices(struct device dev, void c)
	21	{
	22	struct platform_device *pdev = to_platform_device(dev);
	23
	24	platform_device_unregister(pdev);
	25
	26	return 0;
	27	}
	28
0fe763c5	29	static int omap_ocp2scp_probe(struct platform_device *pdev)
26a84b3e	30	{
0133370f	31	int ret;
cdf61240 KVA	32	u32 reg;
	33	void __iomem *regs;
	34	struct resource *res;
0133370f	35	struct device_node *np = pdev->dev.of_node;
26a84b3e KVA	36
	37	if (np) {
	38	ret = of_platform_populate(np, NULL, NULL, &pdev->dev);
	39	if (ret) {
0133370f KVA	40	dev_err(&pdev->dev,
0133370f KVA	41	"failed to add resources for ocp2scp child\n");
26a84b3e KVA	42	goto err0;
	43	}
	44	}
0133370f	45
26a84b3e	46	pm_runtime_enable(&pdev->dev);
cdf61240 KVA	47	/*
	48	* As per AM572x TRM: http://www.ti.com/lit/ug/spruhz6/spruhz6.pdf
	49	* under section 26.3.2.2, table 26-26 OCP2SCP TIMING Caution;
	50	* As per OMAP4430 TRM: http://www.ti.com/lit/ug/swpu231ap/swpu231ap.pdf
	51	* under section 23.12.6.2.2 , Table 23-1213 OCP2SCP TIMING Caution;
	52	* As per OMAP4460 TRM: http://www.ti.com/lit/ug/swpu235ab/swpu235ab.pdf
	53	* under section 23.12.6.2.2, Table 23-1213 OCP2SCP TIMING Caution;
	54	* As per OMAP543x TRM http://www.ti.com/lit/pdf/swpu249
	55	* under section 27.3.2.2, Table 27-27 OCP2SCP TIMING Caution;
	56	*
	57	* Read path of OCP2SCP is not working properly due to low reset value
	58	* of SYNC2 parameter in OCP2SCP. Suggested reset value is 0x6 or more.
	59	*/
	60	if (!of_device_is_compatible(np, "ti,am437x-ocp2scp")) {
	61	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	62	regs = devm_ioremap_resource(&pdev->dev, res);
672647af KVA	63	if (IS_ERR(regs)) {
	64	ret = PTR_ERR(regs);
	65	goto err1;
	66	}
cdf61240 KVA	67
	68	pm_runtime_get_sync(&pdev->dev);
	69	reg = readl_relaxed(regs + OCP2SCP_TIMING);
	70	reg &= ~(SYNC2_MASK);
	71	reg \|= 0x6;
	72	writel_relaxed(reg, regs + OCP2SCP_TIMING);
	73	pm_runtime_put_sync(&pdev->dev);
	74	}
26a84b3e KVA	75
	76	return 0;
	77
672647af KVA	78	err1:
	79	pm_runtime_disable(&pdev->dev);
	80
26a84b3e KVA	81	err0:
	82	device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
	83
	84	return ret;
	85	}
	86
0fe763c5	87	static int omap_ocp2scp_remove(struct platform_device *pdev)
26a84b3e KVA	88	{
	89	pm_runtime_disable(&pdev->dev);
	90	device_for_each_child(&pdev->dev, NULL, ocp2scp_remove_devices);
	91
	92	return 0;
	93	}
	94
	95	#ifdef CONFIG_OF
	96	static const struct of_device_id omap_ocp2scp_id_table[] = {
	97	{ .compatible = "ti,omap-ocp2scp" },
cdf61240	98	{ .compatible = "ti,am437x-ocp2scp" },
26a84b3e KVA	99	{}
26a84b3e KVA	100	};
46ca6811	101	MODULE_DEVICE_TABLE(of, omap_ocp2scp_id_table);
26a84b3e KVA	102	#endif
	103
	104	static struct platform_driver omap_ocp2scp_driver = {
	105	.probe = omap_ocp2scp_probe,
0fe763c5	106	.remove = omap_ocp2scp_remove,
26a84b3e KVA	107	.driver = {
26a84b3e KVA	108	.name = "omap-ocp2scp",
26a84b3e KVA	109	.of_match_table = of_match_ptr(omap_ocp2scp_id_table),
	110	},
	111	};
	112
	113	module_platform_driver(omap_ocp2scp_driver);
	114
7ef71b70	115	MODULE_ALIAS("platform:omap-ocp2scp");
26a84b3e KVA	116	MODULE_AUTHOR("Texas Instruments Inc.");
	117	MODULE_DESCRIPTION("OMAP OCP2SCP driver");
	118	MODULE_LICENSE("GPL v2");