1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * OMAP IOMMU quirks for various TI SoCs
4 *
5 * Copyright (C) 2015-2019 Texas Instruments Incorporated - https://www.ti.com/
6 *      Suman Anna <s-anna@ti.com>
7 */
8
9#include <linux/platform_device.h>
10#include <linux/err.h>
11#include <linux/clk.h>
12#include <linux/list.h>
13
14#include "clockdomain.h"
15#include "powerdomain.h"
16#include "common.h"
17
18struct pwrdm_link {
19	struct device *dev;
20	struct powerdomain *pwrdm;
21	struct list_head node;
22};
23
24static DEFINE_SPINLOCK(iommu_lock);
25static struct clockdomain *emu_clkdm;
26static atomic_t emu_count;
27
28static void omap_iommu_dra7_emu_swsup_config(struct platform_device *pdev,
29					     bool enable)
30{
31	struct device_node *np = pdev->dev.of_node;
32	unsigned long flags;
33
34	if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
35		return;
36
37	if (!emu_clkdm) {
38		emu_clkdm = clkdm_lookup("emu_clkdm");
39		if (WARN_ON_ONCE(!emu_clkdm))
40			return;
41	}
42
43	spin_lock_irqsave(&iommu_lock, flags);
44
45	if (enable && (atomic_inc_return(&emu_count) == 1))
46		clkdm_deny_idle(emu_clkdm);
47	else if (!enable && (atomic_dec_return(&emu_count) == 0))
48		clkdm_allow_idle(emu_clkdm);
49
50	spin_unlock_irqrestore(&iommu_lock, flags);
51}
52
53static struct powerdomain *_get_pwrdm(struct device *dev)
54{
55	struct clk *clk;
56	struct clk_hw_omap *hwclk;
57	struct clockdomain *clkdm;
58	struct powerdomain *pwrdm = NULL;
59	struct pwrdm_link *entry;
60	unsigned long flags;
61	static LIST_HEAD(cache);
62
63	spin_lock_irqsave(&iommu_lock, flags);
64
65	list_for_each_entry(entry, &cache, node) {
66		if (entry->dev == dev) {
67			pwrdm = entry->pwrdm;
68			break;
69		}
70	}
71
72	spin_unlock_irqrestore(&iommu_lock, flags);
73
74	if (pwrdm)
75		return pwrdm;
76
77	clk = of_clk_get(dev->of_node->parent, 0);
78	if (IS_ERR(clk)) {
79		dev_err(dev, "no fck found\n");
80		return NULL;
81	}
82
83	hwclk = to_clk_hw_omap(__clk_get_hw(clk));
84	clk_put(clk);
85	if (!hwclk || !hwclk->clkdm_name) {
86		dev_err(dev, "no hwclk data\n");
87		return NULL;
88	}
89
90	clkdm = clkdm_lookup(hwclk->clkdm_name);
91	if (!clkdm) {
92		dev_err(dev, "clkdm not found: %s\n", hwclk->clkdm_name);
93		return NULL;
94	}
95
96	pwrdm = clkdm_get_pwrdm(clkdm);
97	if (!pwrdm) {
98		dev_err(dev, "pwrdm not found: %s\n", clkdm->name);
99		return NULL;
100	}
101
102	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
103	if (entry) {
104		entry->dev = dev;
105		entry->pwrdm = pwrdm;
106		spin_lock_irqsave(&iommu_lock, flags);
107		list_add(&entry->node, &cache);
108		spin_unlock_irqrestore(&iommu_lock, flags);
109	}
110
111	return pwrdm;
112}
113
114int omap_iommu_set_pwrdm_constraint(struct platform_device *pdev, bool request,
115				    u8 *pwrst)
116{
117	struct powerdomain *pwrdm;
118	u8 next_pwrst;
119	int ret = 0;
120
121	pwrdm = _get_pwrdm(&pdev->dev);
122	if (!pwrdm)
123		return -ENODEV;
124
125	if (request) {
126		*pwrst = pwrdm_read_next_pwrst(pwrdm);
127		omap_iommu_dra7_emu_swsup_config(pdev, true);
128	}
129
130	if (*pwrst > PWRDM_POWER_RET)
131		goto out;
132
133	next_pwrst = request ? PWRDM_POWER_ON : *pwrst;
134
135	ret = pwrdm_set_next_pwrst(pwrdm, next_pwrst);
136
137out:
138	if (!request)
139		omap_iommu_dra7_emu_swsup_config(pdev, false);
140
141	return ret;
142}
143