]> git.sur5r.net Git - u-boot/blobdiff - drivers/i2c/designware_i2c.c
SPDX: Convert all of our single license tags to Linux Kernel style
[u-boot] / drivers / i2c / designware_i2c.c
index e768cdedb0db99530eb9c9a34da290cf1191e0a4..dbc3326b5a9923c78550465ec31a55e7511161a4 100644 (file)
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * (C) Copyright 2009
  * Vipin Kumar, ST Micoelectronics, vipin.kumar@st.com.
- *
- * SPDX-License-Identifier:    GPL-2.0+
  */
 
 #include <common.h>
+#include <dm.h>
 #include <i2c.h>
+#include <pci.h>
+#include <reset.h>
 #include <asm/io.h>
 #include "designware_i2c.h"
 
-static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap)
-{
-       switch (adap->hwadapnr) {
-#if CONFIG_SYS_I2C_BUS_MAX >= 4
-       case 3:
-               return (struct i2c_regs *)CONFIG_SYS_I2C_BASE3;
+struct dw_scl_sda_cfg {
+       u32 ss_hcnt;
+       u32 fs_hcnt;
+       u32 ss_lcnt;
+       u32 fs_lcnt;
+       u32 sda_hold;
+};
+
+#ifdef CONFIG_X86
+/* BayTrail HCNT/LCNT/SDA hold time */
+static struct dw_scl_sda_cfg byt_config = {
+       .ss_hcnt = 0x200,
+       .fs_hcnt = 0x55,
+       .ss_lcnt = 0x200,
+       .fs_lcnt = 0x99,
+       .sda_hold = 0x6,
+};
 #endif
-#if CONFIG_SYS_I2C_BUS_MAX >= 3
-       case 2:
-               return (struct i2c_regs *)CONFIG_SYS_I2C_BASE2;
-#endif
-#if CONFIG_SYS_I2C_BUS_MAX >= 2
-       case 1:
-               return (struct i2c_regs *)CONFIG_SYS_I2C_BASE1;
-#endif
-       case 0:
-               return (struct i2c_regs *)CONFIG_SYS_I2C_BASE;
-       default:
-               printf("Wrong I2C-adapter number %d\n", adap->hwadapnr);
-       }
 
-       return NULL;
+struct dw_i2c {
+       struct i2c_regs *regs;
+       struct dw_scl_sda_cfg *scl_sda_cfg;
+       struct reset_ctl reset_ctl;
+};
+
+#ifdef CONFIG_SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED
+static void dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
+{
+       u32 ena = enable ? IC_ENABLE_0B : 0;
+
+       writel(ena, &i2c_base->ic_enable);
 }
+#else
+static void dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
+{
+       u32 ena = enable ? IC_ENABLE_0B : 0;
+       int timeout = 100;
+
+       do {
+               writel(ena, &i2c_base->ic_enable);
+               if ((readl(&i2c_base->ic_enable_status) & IC_ENABLE_0B) == ena)
+                       return;
+
+               /*
+                * Wait 10 times the signaling period of the highest I2C
+                * transfer supported by the driver (for 400KHz this is
+                * 25us) as described in the DesignWare I2C databook.
+                */
+               udelay(25);
+       } while (timeout--);
+
+       printf("timeout in %sabling I2C adapter\n", enable ? "en" : "dis");
+}
+#endif
 
 /*
- * set_speed - Set the i2c speed mode (standard, high, fast)
- * @i2c_spd:   required i2c speed mode
+ * i2c_set_bus_speed - Set the i2c speed
+ * @speed:     required i2c speed
  *
- * Set the i2c speed mode (standard, high, fast)
+ * Set the i2c speed.
  */
-static void set_speed(struct i2c_adapter *adap, int i2c_spd)
+static unsigned int __dw_i2c_set_bus_speed(struct i2c_regs *i2c_base,
+                                          struct dw_scl_sda_cfg *scl_sda_cfg,
+                                          unsigned int speed)
 {
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
        unsigned int cntl;
        unsigned int hcnt, lcnt;
-       unsigned int enbl;
+       int i2c_spd;
+
+       if (speed >= I2C_MAX_SPEED)
+               i2c_spd = IC_SPEED_MODE_MAX;
+       else if (speed >= I2C_FAST_SPEED)
+               i2c_spd = IC_SPEED_MODE_FAST;
+       else
+               i2c_spd = IC_SPEED_MODE_STANDARD;
 
        /* to set speed cltr must be disabled */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl &= ~IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
+       dw_i2c_enable(i2c_base, false);
 
        cntl = (readl(&i2c_base->ic_con) & (~IC_CON_SPD_MSK));
 
        switch (i2c_spd) {
+#ifndef CONFIG_X86 /* No High-speed for BayTrail yet */
        case IC_SPEED_MODE_MAX:
-               cntl |= IC_CON_SPD_HS;
-               hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
+               cntl |= IC_CON_SPD_SS;
+               if (scl_sda_cfg) {
+                       hcnt = scl_sda_cfg->fs_hcnt;
+                       lcnt = scl_sda_cfg->fs_lcnt;
+               } else {
+                       hcnt = (IC_CLK * MIN_HS_SCL_HIGHTIME) / NANO_TO_MICRO;
+                       lcnt = (IC_CLK * MIN_HS_SCL_LOWTIME) / NANO_TO_MICRO;
+               }
                writel(hcnt, &i2c_base->ic_hs_scl_hcnt);
-               lcnt = (IC_CLK * MIN_HS_SCL_LOWTIME) / NANO_TO_MICRO;
                writel(lcnt, &i2c_base->ic_hs_scl_lcnt);
                break;
+#endif
 
        case IC_SPEED_MODE_STANDARD:
                cntl |= IC_CON_SPD_SS;
-               hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
+               if (scl_sda_cfg) {
+                       hcnt = scl_sda_cfg->ss_hcnt;
+                       lcnt = scl_sda_cfg->ss_lcnt;
+               } else {
+                       hcnt = (IC_CLK * MIN_SS_SCL_HIGHTIME) / NANO_TO_MICRO;
+                       lcnt = (IC_CLK * MIN_SS_SCL_LOWTIME) / NANO_TO_MICRO;
+               }
                writel(hcnt, &i2c_base->ic_ss_scl_hcnt);
-               lcnt = (IC_CLK * MIN_SS_SCL_LOWTIME) / NANO_TO_MICRO;
                writel(lcnt, &i2c_base->ic_ss_scl_lcnt);
                break;
 
        case IC_SPEED_MODE_FAST:
        default:
                cntl |= IC_CON_SPD_FS;
-               hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
+               if (scl_sda_cfg) {
+                       hcnt = scl_sda_cfg->fs_hcnt;
+                       lcnt = scl_sda_cfg->fs_lcnt;
+               } else {
+                       hcnt = (IC_CLK * MIN_FS_SCL_HIGHTIME) / NANO_TO_MICRO;
+                       lcnt = (IC_CLK * MIN_FS_SCL_LOWTIME) / NANO_TO_MICRO;
+               }
                writel(hcnt, &i2c_base->ic_fs_scl_hcnt);
-               lcnt = (IC_CLK * MIN_FS_SCL_LOWTIME) / NANO_TO_MICRO;
                writel(lcnt, &i2c_base->ic_fs_scl_lcnt);
                break;
        }
 
        writel(cntl, &i2c_base->ic_con);
 
-       /* Enable back i2c now speed set */
-       enbl |= IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
-}
-
-/*
- * i2c_set_bus_speed - Set the i2c speed
- * @speed:     required i2c speed
- *
- * Set the i2c speed.
- */
-static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
-                                        unsigned int speed)
-{
-       int i2c_spd;
-
-       if (speed >= I2C_MAX_SPEED)
-               i2c_spd = IC_SPEED_MODE_MAX;
-       else if (speed >= I2C_FAST_SPEED)
-               i2c_spd = IC_SPEED_MODE_FAST;
-       else
-               i2c_spd = IC_SPEED_MODE_STANDARD;
+       /* Configure SDA Hold Time if required */
+       if (scl_sda_cfg)
+               writel(scl_sda_cfg->sda_hold, &i2c_base->ic_sda_hold);
 
-       set_speed(adap, i2c_spd);
-       adap->speed = speed;
+       /* Enable back i2c now speed set */
+       dw_i2c_enable(i2c_base, true);
 
        return 0;
 }
 
-/*
- * i2c_init - Init function
- * @speed:     required i2c speed
- * @slaveaddr: slave address for the device
- *
- * Initialization function.
- */
-static void dw_i2c_init(struct i2c_adapter *adap, int speed,
-                       int slaveaddr)
-{
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
-       unsigned int enbl;
-
-       /* Disable i2c */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl &= ~IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
-
-       writel((IC_CON_SD | IC_CON_SPD_FS | IC_CON_MM), &i2c_base->ic_con);
-       writel(IC_RX_TL, &i2c_base->ic_rx_tl);
-       writel(IC_TX_TL, &i2c_base->ic_tx_tl);
-       dw_i2c_set_bus_speed(adap, speed);
-       writel(IC_STOP_DET, &i2c_base->ic_intr_mask);
-       writel(slaveaddr, &i2c_base->ic_sar);
-
-       /* Enable i2c */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl |= IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
-}
-
 /*
  * i2c_setaddress - Sets the target slave address
  * @i2c_addr:  target i2c address
  *
  * Sets the target slave address.
  */
-static void i2c_setaddress(struct i2c_adapter *adap, unsigned int i2c_addr)
+static void i2c_setaddress(struct i2c_regs *i2c_base, unsigned int i2c_addr)
 {
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
-       unsigned int enbl;
-
        /* Disable i2c */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl &= ~IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
+       dw_i2c_enable(i2c_base, false);
 
        writel(i2c_addr, &i2c_base->ic_tar);
 
        /* Enable i2c */
-       enbl = readl(&i2c_base->ic_enable);
-       enbl |= IC_ENABLE_0B;
-       writel(enbl, &i2c_base->ic_enable);
+       dw_i2c_enable(i2c_base, true);
 }
 
 /*
@@ -172,10 +171,8 @@ static void i2c_setaddress(struct i2c_adapter *adap, unsigned int i2c_addr)
  *
  * Flushes the i2c RX FIFO
  */
-static void i2c_flush_rxfifo(struct i2c_adapter *adap)
+static void i2c_flush_rxfifo(struct i2c_regs *i2c_base)
 {
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
-
        while (readl(&i2c_base->ic_status) & IC_STATUS_RFNE)
                readl(&i2c_base->ic_cmd_data);
 }
@@ -185,9 +182,8 @@ static void i2c_flush_rxfifo(struct i2c_adapter *adap)
  *
  * Waits for bus busy
  */
-static int i2c_wait_for_bb(struct i2c_adapter *adap)
+static int i2c_wait_for_bb(struct i2c_regs *i2c_base)
 {
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
        unsigned long start_time_bb = get_timer(0);
 
        while ((readl(&i2c_base->ic_status) & IC_STATUS_MA) ||
@@ -201,15 +197,13 @@ static int i2c_wait_for_bb(struct i2c_adapter *adap)
        return 0;
 }
 
-static int i2c_xfer_init(struct i2c_adapter *adap, uchar chip, uint addr,
+static int i2c_xfer_init(struct i2c_regs *i2c_base, uchar chip, uint addr,
                         int alen)
 {
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
-
-       if (i2c_wait_for_bb(adap))
+       if (i2c_wait_for_bb(i2c_base))
                return 1;
 
-       i2c_setaddress(adap, chip);
+       i2c_setaddress(i2c_base, chip);
        while (alen) {
                alen--;
                /* high byte address going out first */
@@ -219,9 +213,8 @@ static int i2c_xfer_init(struct i2c_adapter *adap, uchar chip, uint addr,
        return 0;
 }
 
-static int i2c_xfer_finish(struct i2c_adapter *adap)
+static int i2c_xfer_finish(struct i2c_regs *i2c_base)
 {
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
        ulong start_stop_det = get_timer(0);
 
        while (1) {
@@ -233,12 +226,12 @@ static int i2c_xfer_finish(struct i2c_adapter *adap)
                }
        }
 
-       if (i2c_wait_for_bb(adap)) {
+       if (i2c_wait_for_bb(i2c_base)) {
                printf("Timed out waiting for bus\n");
                return 1;
        }
 
-       i2c_flush_rxfifo(adap);
+       i2c_flush_rxfifo(i2c_base);
 
        return 0;
 }
@@ -253,11 +246,11 @@ static int i2c_xfer_finish(struct i2c_adapter *adap)
  *
  * Read from i2c memory.
  */
-static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
-                      int alen, u8 *buffer, int len)
+static int __dw_i2c_read(struct i2c_regs *i2c_base, u8 dev, uint addr,
+                        int alen, u8 *buffer, int len)
 {
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
        unsigned long start_time_rx;
+       unsigned int active = 0;
 
 #ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
        /*
@@ -278,27 +271,37 @@ static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
              addr);
 #endif
 
-       if (i2c_xfer_init(adap, dev, addr, alen))
+       if (i2c_xfer_init(i2c_base, dev, addr, alen))
                return 1;
 
        start_time_rx = get_timer(0);
        while (len) {
-               if (len == 1)
-                       writel(IC_CMD | IC_STOP, &i2c_base->ic_cmd_data);
-               else
-                       writel(IC_CMD, &i2c_base->ic_cmd_data);
+               if (!active) {
+                       /*
+                        * Avoid writing to ic_cmd_data multiple times
+                        * in case this loop spins too quickly and the
+                        * ic_status RFNE bit isn't set after the first
+                        * write. Subsequent writes to ic_cmd_data can
+                        * trigger spurious i2c transfer.
+                        */
+                       if (len == 1)
+                               writel(IC_CMD | IC_STOP, &i2c_base->ic_cmd_data);
+                       else
+                               writel(IC_CMD, &i2c_base->ic_cmd_data);
+                       active = 1;
+               }
 
                if (readl(&i2c_base->ic_status) & IC_STATUS_RFNE) {
                        *buffer++ = (uchar)readl(&i2c_base->ic_cmd_data);
                        len--;
                        start_time_rx = get_timer(0);
-
+                       active = 0;
                } else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
-                               return 1;
+                       return 1;
                }
        }
 
-       return i2c_xfer_finish(adap);
+       return i2c_xfer_finish(i2c_base);
 }
 
 /*
@@ -311,10 +314,9 @@ static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
  *
  * Write to i2c memory.
  */
-static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
-                       int alen, u8 *buffer, int len)
+static int __dw_i2c_write(struct i2c_regs *i2c_base, u8 dev, uint addr,
+                         int alen, u8 *buffer, int len)
 {
-       struct i2c_regs *i2c_base = i2c_get_base(adap);
        int nb = len;
        unsigned long start_time_tx;
 
@@ -337,7 +339,7 @@ static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
              addr);
 #endif
 
-       if (i2c_xfer_init(adap, dev, addr, alen))
+       if (i2c_xfer_init(i2c_base, dev, addr, alen))
                return 1;
 
        start_time_tx = get_timer(0);
@@ -358,21 +360,99 @@ static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
                }
        }
 
-       return i2c_xfer_finish(adap);
+       return i2c_xfer_finish(i2c_base);
+}
+
+/*
+ * __dw_i2c_init - Init function
+ * @speed:     required i2c speed
+ * @slaveaddr: slave address for the device
+ *
+ * Initialization function.
+ */
+static void __dw_i2c_init(struct i2c_regs *i2c_base, int speed, int slaveaddr)
+{
+       /* Disable i2c */
+       dw_i2c_enable(i2c_base, false);
+
+       writel(IC_CON_SD | IC_CON_RE | IC_CON_SPD_FS | IC_CON_MM,
+              &i2c_base->ic_con);
+       writel(IC_RX_TL, &i2c_base->ic_rx_tl);
+       writel(IC_TX_TL, &i2c_base->ic_tx_tl);
+       writel(IC_STOP_DET, &i2c_base->ic_intr_mask);
+#ifndef CONFIG_DM_I2C
+       __dw_i2c_set_bus_speed(i2c_base, NULL, speed);
+       writel(slaveaddr, &i2c_base->ic_sar);
+#endif
+
+       /* Enable i2c */
+       dw_i2c_enable(i2c_base, true);
 }
 
+#ifndef CONFIG_DM_I2C
 /*
- * i2c_probe - Probe the i2c chip
+ * The legacy I2C functions. These need to get removed once
+ * all users of this driver are converted to DM.
  */
+static struct i2c_regs *i2c_get_base(struct i2c_adapter *adap)
+{
+       switch (adap->hwadapnr) {
+#if CONFIG_SYS_I2C_BUS_MAX >= 4
+       case 3:
+               return (struct i2c_regs *)CONFIG_SYS_I2C_BASE3;
+#endif
+#if CONFIG_SYS_I2C_BUS_MAX >= 3
+       case 2:
+               return (struct i2c_regs *)CONFIG_SYS_I2C_BASE2;
+#endif
+#if CONFIG_SYS_I2C_BUS_MAX >= 2
+       case 1:
+               return (struct i2c_regs *)CONFIG_SYS_I2C_BASE1;
+#endif
+       case 0:
+               return (struct i2c_regs *)CONFIG_SYS_I2C_BASE;
+       default:
+               printf("Wrong I2C-adapter number %d\n", adap->hwadapnr);
+       }
+
+       return NULL;
+}
+
+static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
+                                        unsigned int speed)
+{
+       adap->speed = speed;
+       return __dw_i2c_set_bus_speed(i2c_get_base(adap), NULL, speed);
+}
+
+static void dw_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
+{
+       __dw_i2c_init(i2c_get_base(adap), speed, slaveaddr);
+}
+
+static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
+                      int alen, u8 *buffer, int len)
+{
+       return __dw_i2c_read(i2c_get_base(adap), dev, addr, alen, buffer, len);
+}
+
+static int dw_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr,
+                       int alen, u8 *buffer, int len)
+{
+       return __dw_i2c_write(i2c_get_base(adap), dev, addr, alen, buffer, len);
+}
+
+/* dw_i2c_probe - Probe the i2c chip */
 static int dw_i2c_probe(struct i2c_adapter *adap, u8 dev)
 {
+       struct i2c_regs *i2c_base = i2c_get_base(adap);
        u32 tmp;
        int ret;
 
        /*
         * Try to read the first location of the chip.
         */
-       ret = dw_i2c_read(adap, dev, 0, 1, (uchar *)&tmp, 1);
+       ret = __dw_i2c_read(i2c_base, dev, 0, 1, (uchar *)&tmp, 1);
        if (ret)
                dw_i2c_init(adap, adap->speed, adap->slaveaddr);
 
@@ -400,3 +480,147 @@ U_BOOT_I2C_ADAP_COMPLETE(dw_3, dw_i2c_init, dw_i2c_probe, dw_i2c_read,
                         dw_i2c_write, dw_i2c_set_bus_speed,
                         CONFIG_SYS_I2C_SPEED3, CONFIG_SYS_I2C_SLAVE3, 3)
 #endif
+
+#else /* CONFIG_DM_I2C */
+/* The DM I2C functions */
+
+static int designware_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
+                              int nmsgs)
+{
+       struct dw_i2c *i2c = dev_get_priv(bus);
+       int ret;
+
+       debug("i2c_xfer: %d messages\n", nmsgs);
+       for (; nmsgs > 0; nmsgs--, msg++) {
+               debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
+               if (msg->flags & I2C_M_RD) {
+                       ret = __dw_i2c_read(i2c->regs, msg->addr, 0, 0,
+                                           msg->buf, msg->len);
+               } else {
+                       ret = __dw_i2c_write(i2c->regs, msg->addr, 0, 0,
+                                            msg->buf, msg->len);
+               }
+               if (ret) {
+                       debug("i2c_write: error sending\n");
+                       return -EREMOTEIO;
+               }
+       }
+
+       return 0;
+}
+
+static int designware_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
+{
+       struct dw_i2c *i2c = dev_get_priv(bus);
+
+       return __dw_i2c_set_bus_speed(i2c->regs, i2c->scl_sda_cfg, speed);
+}
+
+static int designware_i2c_probe_chip(struct udevice *bus, uint chip_addr,
+                                    uint chip_flags)
+{
+       struct dw_i2c *i2c = dev_get_priv(bus);
+       struct i2c_regs *i2c_base = i2c->regs;
+       u32 tmp;
+       int ret;
+
+       /* Try to read the first location of the chip */
+       ret = __dw_i2c_read(i2c_base, chip_addr, 0, 1, (uchar *)&tmp, 1);
+       if (ret)
+               __dw_i2c_init(i2c_base, 0, 0);
+
+       return ret;
+}
+
+static int designware_i2c_probe(struct udevice *bus)
+{
+       struct dw_i2c *priv = dev_get_priv(bus);
+       int ret;
+
+       if (device_is_on_pci_bus(bus)) {
+#ifdef CONFIG_DM_PCI
+               /* Save base address from PCI BAR */
+               priv->regs = (struct i2c_regs *)
+                       dm_pci_map_bar(bus, PCI_BASE_ADDRESS_0, PCI_REGION_MEM);
+#ifdef CONFIG_X86
+               /* Use BayTrail specific timing values */
+               priv->scl_sda_cfg = &byt_config;
+#endif
+#endif
+       } else {
+               priv->regs = (struct i2c_regs *)devfdt_get_addr_ptr(bus);
+       }
+
+       ret = reset_get_by_name(bus, "i2c", &priv->reset_ctl);
+       if (ret)
+               pr_info("reset_get_by_name() failed: %d\n", ret);
+
+       if (&priv->reset_ctl)
+               reset_deassert(&priv->reset_ctl);
+
+       __dw_i2c_init(priv->regs, 0, 0);
+
+       return 0;
+}
+
+static int designware_i2c_bind(struct udevice *dev)
+{
+       static int num_cards;
+       char name[20];
+
+       /* Create a unique device name for PCI type devices */
+       if (device_is_on_pci_bus(dev)) {
+               /*
+                * ToDo:
+                * Setting req_seq in the driver is probably not recommended.
+                * But without a DT alias the number is not configured. And
+                * using this driver is impossible for PCIe I2C devices.
+                * This can be removed, once a better (correct) way for this
+                * is found and implemented.
+                */
+               dev->req_seq = num_cards;
+               sprintf(name, "i2c_designware#%u", num_cards++);
+               device_set_name(dev, name);
+       }
+
+       return 0;
+}
+
+static const struct dm_i2c_ops designware_i2c_ops = {
+       .xfer           = designware_i2c_xfer,
+       .probe_chip     = designware_i2c_probe_chip,
+       .set_bus_speed  = designware_i2c_set_bus_speed,
+};
+
+static const struct udevice_id designware_i2c_ids[] = {
+       { .compatible = "snps,designware-i2c" },
+       { }
+};
+
+U_BOOT_DRIVER(i2c_designware) = {
+       .name   = "i2c_designware",
+       .id     = UCLASS_I2C,
+       .of_match = designware_i2c_ids,
+       .bind   = designware_i2c_bind,
+       .probe  = designware_i2c_probe,
+       .priv_auto_alloc_size = sizeof(struct dw_i2c),
+       .ops    = &designware_i2c_ops,
+};
+
+#ifdef CONFIG_X86
+static struct pci_device_id designware_pci_supported[] = {
+       /* Intel BayTrail has 7 I2C controller located on the PCI bus */
+       { PCI_VDEVICE(INTEL, 0x0f41) },
+       { PCI_VDEVICE(INTEL, 0x0f42) },
+       { PCI_VDEVICE(INTEL, 0x0f43) },
+       { PCI_VDEVICE(INTEL, 0x0f44) },
+       { PCI_VDEVICE(INTEL, 0x0f45) },
+       { PCI_VDEVICE(INTEL, 0x0f46) },
+       { PCI_VDEVICE(INTEL, 0x0f47) },
+       {},
+};
+
+U_BOOT_PCI_DEVICE(i2c_designware, designware_pci_supported);
+#endif
+
+#endif /* CONFIG_DM_I2C */