drivers/soc/fsl/rcpm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // rcpm.c - Freescale QorIQ RCPM driver
   4 //
   5 // Copyright 2019-2020 NXP
   6 //
   7 // Author: Ran Wang <[email protected]>
   8
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/of_address.h>
  13 #include <linux/slab.h>
  14 #include <linux/suspend.h>
  15 #include <linux/kernel.h>
  16 #include <linux/acpi.h>
  17
  18 #define RCPM_WAKEUP_CELL_MAX_SIZE       7
  19
  20 struct rcpm {
  21         unsigned int    wakeup_cells;
  22         void __iomem    *ippdexpcr_base;
  23         bool            little_endian;
  24 };
  25
  26 #define  SCFG_SPARECR8  0x051c
  27
  28 static void copy_ippdexpcr1_setting(u32 val)
  29 {
  30         struct device_node *np;
  31         void __iomem *regs;
  32         u32 reg_val;
  33
  34         np = of_find_compatible_node(NULL, NULL, "fsl,ls1021a-scfg");
  35         if (!np)
  36                 return;
  37
  38         regs = of_iomap(np, 0);
  39         if (!regs)
  40                 return;
  41
  42         reg_val = ioread32be(regs + SCFG_SPARECR8);
  43         iowrite32be(val | reg_val, regs + SCFG_SPARECR8);
  44
  45         iounmap(regs);
  46 }
  47
  48 /**
  49  * rcpm_pm_prepare - performs device-level tasks associated with power
  50  * management, such as programming related to the wakeup source control.
  51  * @dev: Device to handle.
  52  *
  53  */
  54 static int rcpm_pm_prepare(struct device *dev)
  55 {
  56         int i, ret, idx;
  57         void __iomem *base;
  58         struct wakeup_source    *ws;
  59         struct rcpm             *rcpm;
  60         struct device_node      *np = dev->of_node;
  61         u32 value[RCPM_WAKEUP_CELL_MAX_SIZE + 1];
  62         u32 setting[RCPM_WAKEUP_CELL_MAX_SIZE] = {0};
  63
  64         rcpm = dev_get_drvdata(dev);
  65         if (!rcpm)
  66                 return -EINVAL;
  67
  68         base = rcpm->ippdexpcr_base;
  69         idx = wakeup_sources_read_lock();
  70
  71         /* Begin with first registered wakeup source */
  72         for_each_wakeup_source(ws) {
  73
  74                 /* skip object which is not attached to device */
  75                 if (!ws->dev || !ws->dev->parent)
  76                         continue;
  77
  78                 ret = device_property_read_u32_array(ws->dev->parent,
  79                                 "fsl,rcpm-wakeup", value,
  80                                 rcpm->wakeup_cells + 1);
  81
  82                 if (ret)
  83                         continue;
  84
  85                 /*
  86                  * For DT mode, would handle devices with "fsl,rcpm-wakeup"
  87                  * pointing to the current RCPM node.
  88                  *
  89                  * For ACPI mode, currently we assume there is only one
  90                  * RCPM controller existing.
  91                  */
  92                 if (is_of_node(dev->fwnode))
  93                         if (np->phandle != value[0])
  94                                 continue;
  95
  96                 /* Property "#fsl,rcpm-wakeup-cells" of rcpm node defines the
  97                  * number of IPPDEXPCR register cells, and "fsl,rcpm-wakeup"
  98                  * of wakeup source IP contains an integer array: <phandle to
  99                  * RCPM node, IPPDEXPCR0 setting, IPPDEXPCR1 setting,
 100                  * IPPDEXPCR2 setting, etc>.
 101                  *
 102                  * So we will go thought them to collect setting data.
 103                  */
 104                 for (i = 0; i < rcpm->wakeup_cells; i++)
 105                         setting[i] |= value[i + 1];
 106         }
 107
 108         wakeup_sources_read_unlock(idx);
 109
 110         /* Program all IPPDEXPCRn once */
 111         for (i = 0; i < rcpm->wakeup_cells; i++) {
 112                 u32 tmp = setting[i];
 113                 void __iomem *address = base + i * 4;
 114
 115                 if (!tmp)
 116                         continue;
 117
 118                 /* We can only OR related bits */
 119                 if (rcpm->little_endian) {
 120                         tmp |= ioread32(address);
 121                         iowrite32(tmp, address);
 122                 } else {
 123                         tmp |= ioread32be(address);
 124                         iowrite32be(tmp, address);
 125                 }
 126                 /*
 127                  * Workaround of errata A-008646 on SoC LS1021A:
 128                  * There is a bug of register ippdexpcr1.
 129                  * Reading configuration register RCPM_IPPDEXPCR1
 130                  * always return zero. So save ippdexpcr1's value
 131                  * to register SCFG_SPARECR8.And the value of
 132                  * ippdexpcr1 will be read from SCFG_SPARECR8.
 133                  */
 134                 if (dev_of_node(dev) && (i == 1))
 135                         if (of_device_is_compatible(np, "fsl,ls1021a-rcpm"))
 136                                 copy_ippdexpcr1_setting(tmp);
 137         }
 138
 139         return 0;
 140 }
 141
 142 static const struct dev_pm_ops rcpm_pm_ops = {
 143         .prepare =  rcpm_pm_prepare,
 144 };
 145
 146 static int rcpm_probe(struct platform_device *pdev)
 147 {
 148         struct device   *dev = &pdev->dev;
 149         struct rcpm     *rcpm;
 150         int ret;
 151
 152         rcpm = devm_kzalloc(dev, sizeof(*rcpm), GFP_KERNEL);
 153         if (!rcpm)
 154                 return -ENOMEM;
 155
 156         rcpm->ippdexpcr_base = devm_platform_ioremap_resource(pdev, 0);
 157         if (IS_ERR(rcpm->ippdexpcr_base)) {
 158                 ret =  PTR_ERR(rcpm->ippdexpcr_base);
 159                 return ret;
 160         }
 161
 162         rcpm->little_endian = device_property_read_bool(
 163                         &pdev->dev, "little-endian");
 164
 165         ret = device_property_read_u32(&pdev->dev,
 166                         "#fsl,rcpm-wakeup-cells", &rcpm->wakeup_cells);
 167         if (ret)
 168                 return ret;
 169
 170         dev_set_drvdata(&pdev->dev, rcpm);
 171
 172         return 0;
 173 }
 174
 175 static const struct of_device_id rcpm_of_match[] = {
 176         { .compatible = "fsl,qoriq-rcpm-2.1+", },
 177         {}
 178 };
 179 MODULE_DEVICE_TABLE(of, rcpm_of_match);
 180
 181 #ifdef CONFIG_ACPI
 182 static const struct acpi_device_id rcpm_acpi_ids[] = {
 183         {"NXP0015",},
 184         { }
 185 };
 186 MODULE_DEVICE_TABLE(acpi, rcpm_acpi_ids);
 187 #endif
 188
 189 static struct platform_driver rcpm_driver = {
 190         .driver = {
 191                 .name = "rcpm",
 192                 .of_match_table = rcpm_of_match,
 193                 .acpi_match_table = ACPI_PTR(rcpm_acpi_ids),
 194                 .pm     = &rcpm_pm_ops,
 195         },
 196         .probe = rcpm_probe,
 197 };
 198
 199 module_platform_driver(rcpm_driver);