linux/arch/arm/mach-omap2/omap-iommu.c

142 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* OMAP IOMMU quirks for various TI SoCs
*
* Copyright (C) 2015-2019 Texas Instruments Incorporated - http://www.ti.com/
* Suman Anna <s-anna@ti.com>
*/
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/list.h>
#include "clockdomain.h"
#include "powerdomain.h"
struct pwrdm_link {
struct device *dev;
struct powerdomain *pwrdm;
struct list_head node;
};
static DEFINE_SPINLOCK(iommu_lock);
static struct clockdomain *emu_clkdm;
static atomic_t emu_count;
static void omap_iommu_dra7_emu_swsup_config(struct platform_device *pdev,
bool enable)
{
struct device_node *np = pdev->dev.of_node;
unsigned long flags;
if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
return;
if (!emu_clkdm) {
emu_clkdm = clkdm_lookup("emu_clkdm");
if (WARN_ON_ONCE(!emu_clkdm))
return;
}
spin_lock_irqsave(&iommu_lock, flags);
if (enable && (atomic_inc_return(&emu_count) == 1))
clkdm_deny_idle(emu_clkdm);
else if (!enable && (atomic_dec_return(&emu_count) == 0))
clkdm_allow_idle(emu_clkdm);
spin_unlock_irqrestore(&iommu_lock, flags);
}
static struct powerdomain *_get_pwrdm(struct device *dev)
{
struct clk *clk;
struct clk_hw_omap *hwclk;
struct clockdomain *clkdm;
struct powerdomain *pwrdm = NULL;
struct pwrdm_link *entry;
unsigned long flags;
static LIST_HEAD(cache);
spin_lock_irqsave(&iommu_lock, flags);
list_for_each_entry(entry, &cache, node) {
if (entry->dev == dev) {
pwrdm = entry->pwrdm;
break;
}
}
spin_unlock_irqrestore(&iommu_lock, flags);
if (pwrdm)
return pwrdm;
clk = of_clk_get(dev->of_node->parent, 0);
if (!clk) {
dev_err(dev, "no fck found\n");
return NULL;
}
hwclk = to_clk_hw_omap(__clk_get_hw(clk));
clk_put(clk);
if (!hwclk || !hwclk->clkdm_name) {
dev_err(dev, "no hwclk data\n");
return NULL;
}
clkdm = clkdm_lookup(hwclk->clkdm_name);
if (!clkdm) {
dev_err(dev, "clkdm not found: %s\n", hwclk->clkdm_name);
return NULL;
}
pwrdm = clkdm_get_pwrdm(clkdm);
if (!pwrdm) {
dev_err(dev, "pwrdm not found: %s\n", clkdm->name);
return NULL;
}
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (entry) {
entry->dev = dev;
entry->pwrdm = pwrdm;
spin_lock_irqsave(&iommu_lock, flags);
list_add(&entry->node, &cache);
spin_unlock_irqrestore(&iommu_lock, flags);
}
return pwrdm;
}
int omap_iommu_set_pwrdm_constraint(struct platform_device *pdev, bool request,
u8 *pwrst)
{
struct powerdomain *pwrdm;
u8 next_pwrst;
int ret = 0;
pwrdm = _get_pwrdm(&pdev->dev);
if (!pwrdm)
return -ENODEV;
if (request) {
*pwrst = pwrdm_read_next_pwrst(pwrdm);
omap_iommu_dra7_emu_swsup_config(pdev, true);
}
if (*pwrst > PWRDM_POWER_RET)
goto out;
next_pwrst = request ? PWRDM_POWER_ON : *pwrst;
ret = pwrdm_set_next_pwrst(pwrdm, next_pwrst);
out:
if (!request)
omap_iommu_dra7_emu_swsup_config(pdev, false);
return ret;
}