arch/x86/cpu/tangier/pinmux.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2018 Emlid Limited
   4  */
   5
   6 #include <common.h>
   7 #include <dm.h>
   8 #include <log.h>
   9 #include <dm/pinctrl.h>
  10 #include <dm/read.h>
  11 #include <regmap.h>
  12 #include <syscon.h>
  13 #include <asm/cpu.h>
  14 #include <asm/scu.h>
  15 #include <linux/io.h>
  16
  17 #define BUFCFG_OFFSET                           0x100
  18
  19 #define MRFLD_FAMILY_LEN                        0x400
  20
  21 /* These are taken from Linux kernel */
  22 #define MRFLD_PINMODE_MASK                      0x07
  23
  24 #define pin_to_bufno(f, p)                      ((p) - (f)->pin_base)
  25
  26 struct mrfld_family {
  27         unsigned int family_number;
  28         unsigned int pin_base;
  29         size_t npins;
  30         void __iomem *regs;
  31 };
  32
  33 #define MRFLD_FAMILY(b, s, e)                           \
  34         {                                               \
  35                 .family_number = (b),                   \
  36                 .pin_base = (s),                        \
  37                 .npins = (e) - (s) + 1,                 \
  38         }
  39
  40 /* Now we only support I2C family of pins */
  41 static struct mrfld_family mrfld_families[] = {
  42         MRFLD_FAMILY(7, 101, 114),
  43 };
  44
  45 struct mrfld_pinctrl {
  46         const struct mrfld_family *families;
  47         size_t nfamilies;
  48 };
  49
  50 static const struct mrfld_family *
  51 mrfld_get_family(struct mrfld_pinctrl *mp, unsigned int pin)
  52 {
  53         const struct mrfld_family *family;
  54         unsigned int i;
  55
  56         for (i = 0; i < mp->nfamilies; i++) {
  57                 family = &mp->families[i];
  58                 if (pin >= family->pin_base &&
  59                     pin < family->pin_base + family->npins)
  60                         return family;
  61         }
  62
  63         pr_err("failed to find family for pin %u\n", pin);
  64         return NULL;
  65 }
  66
  67 static void __iomem *
  68 mrfld_get_bufcfg(struct mrfld_pinctrl *pinctrl, unsigned int pin)
  69 {
  70         const struct mrfld_family *family;
  71         unsigned int bufno;
  72
  73         family =  mrfld_get_family(pinctrl, pin);
  74         if (!family)
  75                 return NULL;
  76
  77         bufno = pin_to_bufno(family, pin);
  78
  79         return family->regs + BUFCFG_OFFSET + bufno * 4;
  80 }
  81
  82 static void
  83 mrfld_setup_families(void *base_addr,
  84                      struct mrfld_family *families, unsigned int nfam)
  85 {
  86         for (int i = 0; i < nfam; i++) {
  87                 struct mrfld_family *family = &families[i];
  88
  89                 family->regs = base_addr +
  90                                family->family_number * MRFLD_FAMILY_LEN;
  91         }
  92 }
  93
  94 static int mrfld_pinconfig_protected(unsigned int pin, u32 mask, u32 bits)
  95 {
  96         struct mrfld_pinctrl *pinctrl;
  97         struct udevice *dev;
  98         void __iomem *bufcfg;
  99         u32 v, value;
 100         int ret;
 101
 102         ret = syscon_get_by_driver_data(X86_SYSCON_PINCONF, &dev);
 103         if (ret)
 104                 return ret;
 105
 106         pinctrl = dev_get_priv(dev);
 107
 108         bufcfg = mrfld_get_bufcfg(pinctrl, pin);
 109         if (!bufcfg)
 110                 return -EINVAL;
 111
 112         value = readl(bufcfg);
 113
 114         v = (value & ~mask) | (bits & mask);
 115
 116         debug("scu: v: 0x%x p: 0x%x bits: %d, mask: %d bufcfg: 0x%p\n",
 117               v, (u32)bufcfg, bits, mask, bufcfg);
 118
 119         ret = scu_ipc_raw_command(IPCMSG_INDIRECT_WRITE, 0, &v, 4,
 120                                   NULL, 0, (u32)bufcfg, 0);
 121         if (ret)
 122                 pr_err("Failed to set mode via SCU for pin %u (%d)\n",
 123                        pin, ret);
 124
 125         return ret;
 126 }
 127
 128 static int mrfld_pinctrl_cfg_pin(ofnode pin_node)
 129 {
 130         bool is_protected;
 131         int pad_offset;
 132         int mode;
 133         u32 mask;
 134         int ret;
 135
 136         /* For now we only support just protected Family of pins */
 137         is_protected = ofnode_read_bool(pin_node, "protected");
 138         if (!is_protected)
 139                 return -ENOTSUPP;
 140
 141         pad_offset = ofnode_read_s32_default(pin_node, "pad-offset", -1);
 142         if (pad_offset == -1)
 143                 return -EINVAL;
 144
 145         mode = ofnode_read_s32_default(pin_node, "mode-func", -1);
 146         if (mode == -1)
 147                 return -EINVAL;
 148
 149         mask = MRFLD_PINMODE_MASK;
 150
 151         /* We don't support modes not in range 0..7 */
 152         if (mode & ~mask)
 153                 return -ENOTSUPP;
 154
 155         ret = mrfld_pinconfig_protected(pad_offset, mask, mode);
 156
 157         return ret;
 158 }
 159
 160 static int tangier_pinctrl_probe(struct udevice *dev)
 161 {
 162         void *base_addr = syscon_get_first_range(X86_SYSCON_PINCONF);
 163         struct mrfld_pinctrl *pinctrl = dev_get_priv(dev);
 164         ofnode pin_node;
 165         int ret;
 166
 167         mrfld_setup_families(base_addr, mrfld_families,
 168                              ARRAY_SIZE(mrfld_families));
 169
 170         pinctrl->families = mrfld_families;
 171         pinctrl->nfamilies = ARRAY_SIZE(mrfld_families);
 172
 173         ofnode_for_each_subnode(pin_node, dev_ofnode(dev)) {
 174                 ret = mrfld_pinctrl_cfg_pin(pin_node);
 175                 if (ret) {
 176                         pr_err("%s: invalid configuration for the pin %ld\n",
 177                                __func__, pin_node.of_offset);
 178                 }
 179         }
 180
 181         return 0;
 182 }
 183
 184 static const struct udevice_id tangier_pinctrl_match[] = {
 185         { .compatible = "intel,pinctrl-tangier", .data = X86_SYSCON_PINCONF },
 186         { /* sentinel */ }
 187 };
 188
 189 U_BOOT_DRIVER(tangier_pinctrl) = {
 190         .name = "tangier_pinctrl",
 191         .id = UCLASS_SYSCON,
 192         .of_match = tangier_pinctrl_match,
 193         .probe = tangier_pinctrl_probe,
 194         .priv_auto_alloc_size = sizeof(struct mrfld_pinctrl),
 195 };