target/linux/at91/patches-5.15/101-clk-at91-pmc-execute-suspend-resume-only-for-backup-.patch

   1 From 63a0c32028148e91ea91cfbf95841c4ecd69d21b Mon Sep 17 00:00:00 2001
   2 From: Claudiu Beznea <claudiu.beznea@microchip.com>
   3 Date: Mon, 11 Oct 2021 14:27:06 +0300
   4 Subject: [PATCH 235/247] clk: at91: pmc: execute suspend/resume only for
   5  backup mode
   6
   7 Before going to backup mode architecture specific PM code sets the first
   8 word in securam (file arch/arm/mach-at91/pm.c, function at91_pm_begin()).
   9 Thus take this into account when suspending/resuming clocks. This will
  10 avoid executing unnecessary instructions when suspending to non backup
  11 modes.
  12
  13 Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
  14 Link: https://lore.kernel.org/r/20211011112719.3951784-3-claudiu.beznea@microchip.com
  15 Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
  16 Signed-off-by: Stephen Boyd <sboyd@kernel.org>
  17 ---
  18  drivers/clk/at91/pmc.c | 39 +++++++++++++++++++++++++++++++++++++++
  19  1 file changed, 39 insertions(+)
  20
  21 --- a/drivers/clk/at91/pmc.c
  22 +++ b/drivers/clk/at91/pmc.c
  23 @@ -8,6 +8,7 @@
  24  #include <linux/clkdev.h>
  25  #include <linux/clk/at91_pmc.h>
  26  #include <linux/of.h>
  27 +#include <linux/of_address.h>
  28  #include <linux/mfd/syscon.h>
  29  #include <linux/platform_device.h>
  30  #include <linux/regmap.h>
  31 @@ -110,13 +111,35 @@ struct pmc_data *pmc_data_allocate(unsig
  32  }
  33
  34  #ifdef CONFIG_PM
  35 +
  36 +/* Address in SECURAM that say if we suspend to backup mode. */
  37 +static void __iomem *at91_pmc_backup_suspend;
  38 +
  39  static int at91_pmc_suspend(void)
  40  {
  41 +       unsigned int backup;
  42 +
  43 +       if (!at91_pmc_backup_suspend)
  44 +               return 0;
  45 +
  46 +       backup = readl_relaxed(at91_pmc_backup_suspend);
  47 +       if (!backup)
  48 +               return 0;
  49 +
  50         return clk_save_context();
  51  }
  52
  53  static void at91_pmc_resume(void)
  54  {
  55 +       unsigned int backup;
  56 +
  57 +       if (!at91_pmc_backup_suspend)
  58 +               return;
  59 +
  60 +       backup = readl_relaxed(at91_pmc_backup_suspend);
  61 +       if (!backup)
  62 +               return;
  63 +
  64         clk_restore_context();
  65  }
  66
  67 @@ -144,6 +167,22 @@ static int __init pmc_register_ops(void)
  68         }
  69         of_node_put(np);
  70
  71 +       np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam");
  72 +       if (!np)
  73 +               return -ENODEV;
  74 +
  75 +       if (!of_device_is_available(np)) {
  76 +               of_node_put(np);
  77 +               return -ENODEV;
  78 +       }
  79 +       of_node_put(np);
  80 +
  81 +       at91_pmc_backup_suspend = of_iomap(np, 0);
  82 +       if (!at91_pmc_backup_suspend) {
  83 +               pr_warn("%s(): unable to map securam\n", __func__);
  84 +               return -ENOMEM;
  85 +       }
  86 +
  87         register_syscore_ops(&pmc_syscore_ops);
  88
  89         return 0;