src/soc/rockchip/rk3288/software_i2c.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <device/mmio.h>
   4 #include <console/console.h>
   5 #include <device/i2c_simple.h>
   6 #include <gpio.h>
   7 #include <soc/grf.h>
   8 #include <soc/i2c.h>
   9 #include <soc/pmu.h>
  10
  11 static struct {
  12         gpio_t scl;
  13         gpio_t sda;
  14 } pins[] = {
  15         [0]{.scl = GPIO(0, C, 0), .sda = GPIO(0, B, 7)},
  16         [1]{.scl = GPIO(8, A, 5), .sda = GPIO(8, A, 4)},
  17         [2]{.scl = GPIO(6, B, 2), .sda = GPIO(6, B, 1)},
  18         [3]{.scl = GPIO(2, C, 0), .sda = GPIO(2, C, 1)},
  19         [4]{.scl = GPIO(7, C, 2), .sda = GPIO(7, C, 1)},
  20         [5]{.scl = GPIO(7, C, 4), .sda = GPIO(7, C, 3)},
  21 };
  22
  23 static int get_scl(unsigned int bus)
  24 {
  25         return gpio_get(pins[bus].scl);
  26 }
  27
  28 static int get_sda(unsigned int bus)
  29 {
  30         return gpio_get(pins[bus].sda);
  31 }
  32
  33 static void set_scl(unsigned int bus, int high)
  34 {
  35         if (high)
  36                 gpio_input_pullup(pins[bus].scl);
  37         else
  38                 gpio_output(pins[bus].scl, 0);
  39 }
  40
  41 static void set_sda(unsigned int bus, int high)
  42 {
  43         if (high)
  44                 gpio_input_pullup(pins[bus].sda);
  45         else
  46                 gpio_output(pins[bus].sda, 0);
  47 }
  48
  49 static struct software_i2c_ops rk_ops = {
  50         .get_scl = get_scl,
  51         .get_sda = get_sda,
  52         .set_scl = set_scl,
  53         .set_sda = set_sda,
  54 };
  55
  56 void software_i2c_attach(unsigned int bus)
  57 {
  58         software_i2c[bus] = &rk_ops;
  59
  60         /* Mux pins to GPIO function for software I2C emulation. */
  61         switch (bus) {
  62         case 0:
  63                 clrbits32(&rk3288_pmu->iomux_i2c0scl, IOMUX_I2C0SCL);
  64                 clrbits32(&rk3288_pmu->iomux_i2c0sda, IOMUX_I2C0SDA);
  65                 break;
  66         case 1:
  67                 write32(&rk3288_grf->iomux_i2c1, IOMUX_GPIO(IOMUX_I2C1));
  68                 break;
  69         case 2:
  70                 write32(&rk3288_grf->iomux_i2c2, IOMUX_GPIO(IOMUX_I2C2));
  71                 break;
  72         case 3:
  73                 write32(&rk3288_grf->iomux_i2c3, IOMUX_GPIO(IOMUX_I2C3));
  74                 break;
  75         case 4:
  76                 write32(&rk3288_grf->iomux_i2c4, IOMUX_GPIO(IOMUX_I2C4));
  77                 break;
  78         case 5:
  79                 write32(&rk3288_grf->iomux_i2c5scl, IOMUX_GPIO(IOMUX_I2C5SCL));
  80                 write32(&rk3288_grf->iomux_i2c5sda, IOMUX_GPIO(IOMUX_I2C5SDA));
  81                 break;
  82         default:
  83                 die("Unknown I2C bus number!");
  84         }
  85
  86         /* Initialize bus to idle state. */
  87         set_scl(bus, 1);
  88         set_sda(bus, 1);
  89 }
  90
  91 void software_i2c_detach(unsigned int bus)
  92 {
  93         software_i2c[bus] = NULL;
  94
  95         /* Mux pins back to hardware I2C controller. */
  96         switch (bus) {
  97         case 0:
  98                 setbits32(&rk3288_pmu->iomux_i2c0scl, IOMUX_I2C0SCL);
  99                 setbits32(&rk3288_pmu->iomux_i2c0sda, IOMUX_I2C0SDA);
 100                 break;
 101         case 1:
 102                 write32(&rk3288_grf->iomux_i2c1, IOMUX_I2C1);
 103                 break;
 104         case 2:
 105                 write32(&rk3288_grf->iomux_i2c2, IOMUX_I2C2);
 106                 break;
 107         case 3:
 108                 write32(&rk3288_grf->iomux_i2c3, IOMUX_I2C3);
 109                 break;
 110         case 4:
 111                 write32(&rk3288_grf->iomux_i2c4, IOMUX_I2C4);
 112                 break;
 113         case 5:
 114                 write32(&rk3288_grf->iomux_i2c5scl, IOMUX_I2C5SCL);
 115                 write32(&rk3288_grf->iomux_i2c5sda, IOMUX_I2C5SDA);
 116                 break;
 117         default:
 118                 die("Unknown I2C bus number!");
 119         }
 120 }