drivers/i2c/sun8i_rsb.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * (C) Copyright 2014 Hans de Goede <hdegoede@redhat.com>
   4  *
   5  * Based on allwinner u-boot sources rsb code which is:
   6  * (C) Copyright 2007-2013
   7  * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
   8  * lixiang <lixiang@allwinnertech.com>
   9  */
  10
  11 #include <axp_pmic.h>
  12 #include <clk.h>
  13 #include <common.h>
  14 #include <dm.h>
  15 #include <errno.h>
  16 #include <i2c.h>
  17 #include <reset.h>
  18 #include <time.h>
  19 #include <asm/arch/cpu.h>
  20 #include <asm/arch/gpio.h>
  21 #include <asm/arch/prcm.h>
  22 #include <asm/arch/rsb.h>
  23
  24 static int sun8i_rsb_await_trans(struct sunxi_rsb_reg *base)
  25 {
  26         unsigned long tmo = timer_get_us() + 1000000;
  27         u32 stat;
  28         int ret;
  29
  30         while (1) {
  31                 stat = readl(&base->stat);
  32                 if (stat & RSB_STAT_LBSY_INT) {
  33                         ret = -EBUSY;
  34                         break;
  35                 }
  36                 if (stat & RSB_STAT_TERR_INT) {
  37                         ret = -EIO;
  38                         break;
  39                 }
  40                 if (stat & RSB_STAT_TOVER_INT) {
  41                         ret = 0;
  42                         break;
  43                 }
  44                 if (timer_get_us() > tmo) {
  45                         ret = -ETIME;
  46                         break;
  47                 }
  48         }
  49         writel(stat, &base->stat); /* Clear status bits */
  50
  51         return ret;
  52 }
  53
  54 static int sun8i_rsb_do_trans(struct sunxi_rsb_reg *base)
  55 {
  56         setbits_le32(&base->ctrl, RSB_CTRL_START_TRANS);
  57
  58         return sun8i_rsb_await_trans(base);
  59 }
  60
  61 static int sun8i_rsb_read(struct sunxi_rsb_reg *base, u16 runtime_addr,
  62                           u8 reg_addr, u8 *data)
  63 {
  64         int ret;
  65
  66         writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_addr), &base->devaddr);
  67         writel(reg_addr, &base->addr);
  68         writel(RSB_CMD_BYTE_READ, &base->cmd);
  69
  70         ret = sun8i_rsb_do_trans(base);
  71         if (ret)
  72                 return ret;
  73
  74         *data = readl(&base->data) & 0xff;
  75
  76         return 0;
  77 }
  78
  79 static int sun8i_rsb_write(struct sunxi_rsb_reg *base, u16 runtime_addr,
  80                            u8 reg_addr, u8 data)
  81 {
  82         writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_addr), &base->devaddr);
  83         writel(reg_addr, &base->addr);
  84         writel(data, &base->data);
  85         writel(RSB_CMD_BYTE_WRITE, &base->cmd);
  86
  87         return sun8i_rsb_do_trans(base);
  88 }
  89
  90 static int sun8i_rsb_set_device_address(struct sunxi_rsb_reg *base,
  91                                         u16 device_addr, u16 runtime_addr)
  92 {
  93         writel(RSB_DEVADDR_RUNTIME_ADDR(runtime_addr) |
  94                RSB_DEVADDR_DEVICE_ADDR(device_addr), &base->devaddr);
  95         writel(RSB_CMD_SET_RTSADDR, &base->cmd);
  96
  97         return sun8i_rsb_do_trans(base);
  98 }
  99
 100 static void sun8i_rsb_set_clk(struct sunxi_rsb_reg *base)
 101 {
 102         u32 div = 0;
 103         u32 cd_odly = 0;
 104
 105         /* Source is Hosc24M, set RSB clk to 3Mhz */
 106         div = 24000000 / 3000000 / 2 - 1;
 107         cd_odly = div >> 1;
 108         if (!cd_odly)
 109                 cd_odly = 1;
 110
 111         writel((cd_odly << 8) | div, &base->ccr);
 112 }
 113
 114 static int sun8i_rsb_set_device_mode(struct sunxi_rsb_reg *base)
 115 {
 116         unsigned long tmo = timer_get_us() + 1000000;
 117
 118         writel(RSB_DMCR_DEVICE_MODE_START | RSB_DMCR_DEVICE_MODE_DATA,
 119                &base->dmcr);
 120
 121         while (readl(&base->dmcr) & RSB_DMCR_DEVICE_MODE_START) {
 122                 if (timer_get_us() > tmo)
 123                         return -ETIME;
 124         }
 125
 126         return sun8i_rsb_await_trans(base);
 127 }
 128
 129 static int sun8i_rsb_init(struct sunxi_rsb_reg *base)
 130 {
 131         writel(RSB_CTRL_SOFT_RST, &base->ctrl);
 132         sun8i_rsb_set_clk(base);
 133
 134         return sun8i_rsb_set_device_mode(base);
 135 }
 136
 137 #if IS_ENABLED(CONFIG_AXP_PMIC_BUS)
 138 int rsb_read(const u16 runtime_addr, const u8 reg_addr, u8 *data)
 139 {
 140         struct sunxi_rsb_reg *base = (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
 141
 142         return sun8i_rsb_read(base, runtime_addr, reg_addr, data);
 143 }
 144
 145 int rsb_write(const u16 runtime_addr, const u8 reg_addr, u8 data)
 146 {
 147         struct sunxi_rsb_reg *base = (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
 148
 149         return sun8i_rsb_write(base, runtime_addr, reg_addr, data);
 150 }
 151
 152 int rsb_set_device_address(u16 device_addr, u16 runtime_addr)
 153 {
 154         struct sunxi_rsb_reg *base = (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
 155
 156         return sun8i_rsb_set_device_address(base, device_addr, runtime_addr);
 157 }
 158
 159 int rsb_init(void)
 160 {
 161         struct sunxi_rsb_reg *base = (struct sunxi_rsb_reg *)SUNXI_RSB_BASE;
 162
 163         /* Enable RSB and PIO clk, and de-assert their resets */
 164         prcm_apb0_enable(PRCM_APB0_GATE_PIO | PRCM_APB0_GATE_RSB);
 165
 166         if (IS_ENABLED(CONFIG_MACH_SUN9I)) {
 167                 sunxi_gpio_set_cfgpin(SUNXI_GPN(0), SUN9I_GPN_R_RSB);
 168                 sunxi_gpio_set_cfgpin(SUNXI_GPN(1), SUN9I_GPN_R_RSB);
 169                 sunxi_gpio_set_pull(SUNXI_GPN(0), 1);
 170                 sunxi_gpio_set_pull(SUNXI_GPN(1), 1);
 171                 sunxi_gpio_set_drv(SUNXI_GPN(0), 2);
 172                 sunxi_gpio_set_drv(SUNXI_GPN(1), 2);
 173         } else {
 174                 sunxi_gpio_set_cfgpin(SUNXI_GPL(0), SUN8I_GPL_R_RSB);
 175                 sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUN8I_GPL_R_RSB);
 176                 sunxi_gpio_set_pull(SUNXI_GPL(0), 1);
 177                 sunxi_gpio_set_pull(SUNXI_GPL(1), 1);
 178                 sunxi_gpio_set_drv(SUNXI_GPL(0), 2);
 179                 sunxi_gpio_set_drv(SUNXI_GPL(1), 2);
 180         }
 181
 182         return sun8i_rsb_init(base);
 183 }
 184 #endif
 185
 186 #if CONFIG_IS_ENABLED(DM_I2C)
 187 struct sun8i_rsb_priv {
 188         struct sunxi_rsb_reg *base;
 189 };
 190
 191 /*
 192  * The mapping from hardware address to runtime address is fixed, and shared
 193  * among all RSB drivers. See the comment in drivers/bus/sunxi-rsb.c in Linux.
 194  */
 195 static int sun8i_rsb_get_runtime_address(u16 device_addr)
 196 {
 197         if (device_addr == AXP_PMIC_PRI_DEVICE_ADDR)
 198                 return AXP_PMIC_PRI_RUNTIME_ADDR;
 199         if (device_addr == AXP_PMIC_SEC_DEVICE_ADDR)
 200                 return AXP_PMIC_SEC_RUNTIME_ADDR;
 201
 202         return -ENXIO;
 203 }
 204
 205 static int sun8i_rsb_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
 206 {
 207         int runtime_addr = sun8i_rsb_get_runtime_address(msg->addr);
 208         struct sun8i_rsb_priv *priv = dev_get_priv(bus);
 209
 210         if (runtime_addr < 0)
 211                 return runtime_addr;
 212
 213         /* The hardware only supports SMBus-style transfers. */
 214         if (nmsgs == 2 && msg[1].flags == I2C_M_RD && msg[1].len == 1)
 215                 return sun8i_rsb_read(priv->base, runtime_addr,
 216                                       msg[0].buf[0], &msg[1].buf[0]);
 217
 218         if (nmsgs == 1 && msg[0].len == 2)
 219                 return sun8i_rsb_write(priv->base, runtime_addr,
 220                                        msg[0].buf[0], msg[0].buf[1]);
 221
 222         return -EINVAL;
 223 }
 224
 225 static int sun8i_rsb_probe_chip(struct udevice *bus, uint chip_addr,
 226                                 uint chip_flags)
 227 {
 228         int runtime_addr = sun8i_rsb_get_runtime_address(chip_addr);
 229         struct sun8i_rsb_priv *priv = dev_get_priv(bus);
 230
 231         if (runtime_addr < 0)
 232                 return runtime_addr;
 233
 234         return sun8i_rsb_set_device_address(priv->base, chip_addr, runtime_addr);
 235 }
 236
 237 static int sun8i_rsb_probe(struct udevice *bus)
 238 {
 239         struct sun8i_rsb_priv *priv = dev_get_priv(bus);
 240         struct reset_ctl *reset;
 241         struct clk *clk;
 242
 243         priv->base = dev_read_addr_ptr(bus);
 244
 245         reset = devm_reset_control_get(bus, NULL);
 246         if (!IS_ERR(reset))
 247                 reset_deassert(reset);
 248
 249         clk = devm_clk_get(bus, NULL);
 250         if (!IS_ERR(clk))
 251                 clk_enable(clk);
 252
 253         return sun8i_rsb_init(priv->base);
 254 }
 255
 256 static int sun8i_rsb_child_pre_probe(struct udevice *child)
 257 {
 258         struct dm_i2c_chip *chip = dev_get_parent_plat(child);
 259         struct udevice *bus = child->parent;
 260
 261         /* Ensure each transfer is for a single register. */
 262         chip->flags |= DM_I2C_CHIP_RD_ADDRESS | DM_I2C_CHIP_WR_ADDRESS;
 263
 264         return sun8i_rsb_probe_chip(bus, chip->chip_addr, 0);
 265 }
 266
 267 static const struct dm_i2c_ops sun8i_rsb_ops = {
 268         .xfer           = sun8i_rsb_xfer,
 269         .probe_chip     = sun8i_rsb_probe_chip,
 270 };
 271
 272 static const struct udevice_id sun8i_rsb_ids[] = {
 273         { .compatible = "allwinner,sun8i-a23-rsb" },
 274         { /* sentinel */ }
 275 };
 276
 277 U_BOOT_DRIVER(sun8i_rsb) = {
 278         .name                   = "sun8i_rsb",
 279         .id                     = UCLASS_I2C,
 280         .of_match               = sun8i_rsb_ids,
 281         .probe                  = sun8i_rsb_probe,
 282         .child_pre_probe        = sun8i_rsb_child_pre_probe,
 283         .priv_auto              = sizeof(struct sun8i_rsb_priv),
 284         .ops                    = &sun8i_rsb_ops,
 285 };
 286 #endif /* CONFIG_IS_ENABLED(DM_I2C) */