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

   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 - http://www.ti.com/
   6  *      Suman Anna <s-anna@ti.com>
   7  */
   8
   9 #include <linux/platform_device.h>
  10 #include <linux/err.h>
  11
  12 #include "omap_hwmod.h"
  13 #include "omap_device.h"
  14 #include "clockdomain.h"
  15 #include "powerdomain.h"
  16
  17 static void omap_iommu_dra7_emu_swsup_config(struct platform_device *pdev,
  18                                              bool enable)
  19 {
  20         static struct clockdomain *emu_clkdm;
  21         static DEFINE_SPINLOCK(emu_lock);
  22         static atomic_t count;
  23         struct device_node *np = pdev->dev.of_node;
  24
  25         if (!of_device_is_compatible(np, "ti,dra7-dsp-iommu"))
  26                 return;
  27
  28         if (!emu_clkdm) {
  29                 emu_clkdm = clkdm_lookup("emu_clkdm");
  30                 if (WARN_ON_ONCE(!emu_clkdm))
  31                         return;
  32         }
  33
  34         spin_lock(&emu_lock);
  35
  36         if (enable && (atomic_inc_return(&count) == 1))
  37                 clkdm_deny_idle(emu_clkdm);
  38         else if (!enable && (atomic_dec_return(&count) == 0))
  39                 clkdm_allow_idle(emu_clkdm);
  40
  41         spin_unlock(&emu_lock);
  42 }
  43
  44 int omap_iommu_set_pwrdm_constraint(struct platform_device *pdev, bool request,
  45                                     u8 *pwrst)
  46 {
  47         struct powerdomain *pwrdm;
  48         struct omap_device *od;
  49         u8 next_pwrst;
  50         int ret = 0;
  51
  52         od = to_omap_device(pdev);
  53         if (!od)
  54                 return -ENODEV;
  55
  56         if (od->hwmods_cnt != 1)
  57                 return -EINVAL;
  58
  59         pwrdm = omap_hwmod_get_pwrdm(od->hwmods[0]);
  60         if (!pwrdm)
  61                 return -EINVAL;
  62
  63         if (request) {
  64                 *pwrst = pwrdm_read_next_pwrst(pwrdm);
  65                 omap_iommu_dra7_emu_swsup_config(pdev, true);
  66         }
  67
  68         if (*pwrst > PWRDM_POWER_RET)
  69                 goto out;
  70
  71         next_pwrst = request ? PWRDM_POWER_ON : *pwrst;
  72
  73         ret = pwrdm_set_next_pwrst(pwrdm, next_pwrst);
  74
  75 out:
  76         if (!request)
  77                 omap_iommu_dra7_emu_swsup_config(pdev, false);
  78
  79         return ret;
  80 }