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 <ran.wang_1@nxp.com>
   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
  17 #define RCPM_WAKEUP_CELL_MAX_SIZE       7
  18
  19 struct rcpm {
  20         unsigned int    wakeup_cells;
  21         void __iomem    *ippdexpcr_base;
  22         bool            little_endian;
  23 };
  24
  25 #define  SCFG_SPARECR8  0x051c
  26
  27 static void copy_ippdexpcr1_setting(u32 val)
  28 {
  29         struct device_node *np;
  30         void __iomem *regs;
  31         u32 reg_val;
  32
  33         np = of_find_compatible_node(NULL, NULL, "fsl,ls1021a-scfg");
  34         if (!np)
  35                 return;
  36
  37         regs = of_iomap(np, 0);
  38         if (!regs)
  39                 return;
  40
  41         reg_val = ioread32be(regs + SCFG_SPARECR8);
  42         iowrite32be(val | reg_val, regs + SCFG_SPARECR8);
  43
  44         iounmap(regs);
  45 }
  46
  47 /**
  48  * rcpm_pm_prepare - performs device-level tasks associated with power
  49  * management, such as programming related to the wakeup source control.
  50  * @dev: Device to handle.
  51  *
  52  */
  53 static int rcpm_pm_prepare(struct device *dev)
  54 {
  55         int i, ret, idx;
  56         void __iomem *base;
  57         struct wakeup_source    *ws;
  58         struct rcpm             *rcpm;
  59         struct device_node      *np = dev->of_node;
  60         u32 value[RCPM_WAKEUP_CELL_MAX_SIZE + 1];
  61         u32 setting[RCPM_WAKEUP_CELL_MAX_SIZE] = {0};
  62
  63         rcpm = dev_get_drvdata(dev);
  64         if (!rcpm)
  65                 return -EINVAL;
  66
  67         base = rcpm->ippdexpcr_base;
  68         idx = wakeup_sources_read_lock();
  69
  70         /* Begin with first registered wakeup source */
  71         for_each_wakeup_source(ws) {
  72
  73                 /* skip object which is not attached to device */
  74                 if (!ws->dev || !ws->dev->parent)
  75                         continue;
  76
  77                 ret = device_property_read_u32_array(ws->dev->parent,
  78                                 "fsl,rcpm-wakeup", value,
  79                                 rcpm->wakeup_cells + 1);
  80
  81                 /*  Wakeup source should refer to current rcpm device */
  82                 if (ret || (np->phandle != value[0]))
  83                         continue;
  84
  85                 /* Property "#fsl,rcpm-wakeup-cells" of rcpm node defines the
  86                  * number of IPPDEXPCR register cells, and "fsl,rcpm-wakeup"
  87                  * of wakeup source IP contains an integer array: <phandle to
  88                  * RCPM node, IPPDEXPCR0 setting, IPPDEXPCR1 setting,
  89                  * IPPDEXPCR2 setting, etc>.
  90                  *
  91                  * So we will go thought them to collect setting data.
  92                  */
  93                 for (i = 0; i < rcpm->wakeup_cells; i++)
  94                         setting[i] |= value[i + 1];
  95         }
  96
  97         wakeup_sources_read_unlock(idx);
  98
  99         /* Program all IPPDEXPCRn once */
 100         for (i = 0; i < rcpm->wakeup_cells; i++) {
 101                 u32 tmp = setting[i];
 102                 void __iomem *address = base + i * 4;
 103
 104                 if (!tmp)
 105                         continue;
 106
 107                 /* We can only OR related bits */
 108                 if (rcpm->little_endian) {
 109                         tmp |= ioread32(address);
 110                         iowrite32(tmp, address);
 111                 } else {
 112                         tmp |= ioread32be(address);
 113                         iowrite32be(tmp, address);
 114                 }
 115                 /*
 116                  * Workaround of errata A-008646 on SoC LS1021A:
 117                  * There is a bug of register ippdexpcr1.
 118                  * Reading configuration register RCPM_IPPDEXPCR1
 119                  * always return zero. So save ippdexpcr1's value
 120                  * to register SCFG_SPARECR8.And the value of
 121                  * ippdexpcr1 will be read from SCFG_SPARECR8.
 122                  */
 123                 if (dev_of_node(dev) && (i == 1))
 124                         if (of_device_is_compatible(np, "fsl,ls1021a-rcpm"))
 125                                 copy_ippdexpcr1_setting(tmp);
 126         }
 127
 128         return 0;
 129 }
 130
 131 static const struct dev_pm_ops rcpm_pm_ops = {
 132         .prepare =  rcpm_pm_prepare,
 133 };
 134
 135 static int rcpm_probe(struct platform_device *pdev)
 136 {
 137         struct device   *dev = &pdev->dev;
 138         struct resource *r;
 139         struct rcpm     *rcpm;
 140         int ret;
 141
 142         rcpm = devm_kzalloc(dev, sizeof(*rcpm), GFP_KERNEL);
 143         if (!rcpm)
 144                 return -ENOMEM;
 145
 146         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 147         if (!r)
 148                 return -ENODEV;
 149
 150         rcpm->ippdexpcr_base = devm_ioremap_resource(&pdev->dev, r);
 151         if (IS_ERR(rcpm->ippdexpcr_base)) {
 152                 ret =  PTR_ERR(rcpm->ippdexpcr_base);
 153                 return ret;
 154         }
 155
 156         rcpm->little_endian = device_property_read_bool(
 157                         &pdev->dev, "little-endian");
 158
 159         ret = device_property_read_u32(&pdev->dev,
 160                         "#fsl,rcpm-wakeup-cells", &rcpm->wakeup_cells);
 161         if (ret)
 162                 return ret;
 163
 164         dev_set_drvdata(&pdev->dev, rcpm);
 165
 166         return 0;
 167 }
 168
 169 static const struct of_device_id rcpm_of_match[] = {
 170         { .compatible = "fsl,qoriq-rcpm-2.1+", },
 171         {}
 172 };
 173 MODULE_DEVICE_TABLE(of, rcpm_of_match);
 174
 175 static struct platform_driver rcpm_driver = {
 176         .driver = {
 177                 .name = "rcpm",
 178                 .of_match_table = rcpm_of_match,
 179                 .pm     = &rcpm_pm_ops,
 180         },
 181         .probe = rcpm_probe,
 182 };
 183
 184 module_platform_driver(rcpm_driver);