--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2020
+ * Arthur Li, Cortina Access, arthur.li@cortina-access.com.
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <log.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <mapmem.h>
+#include "i2c-cortina.h"
+
+static void set_speed(struct i2c_regs *regs, int i2c_spd)
+{
+ union ca_biw_cfg i2c_cfg;
+
+ i2c_cfg.wrd = readl(®s->i2c_cfg);
+ i2c_cfg.bf.core_en = 0;
+ writel(i2c_cfg.wrd, ®s->i2c_cfg);
+
+ switch (i2c_spd) {
+ case IC_SPEED_MODE_FAST_PLUS:
+ i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
+ (5 * I2C_SPEED_FAST_PLUS_RATE) - 1;
+ break;
+
+ case IC_SPEED_MODE_STANDARD:
+ i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
+ (5 * I2C_SPEED_STANDARD_RATE) - 1;
+ break;
+
+ case IC_SPEED_MODE_FAST:
+ default:
+ i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
+ (5 * I2C_SPEED_FAST_RATE) - 1;
+ break;
+ }
+
+ i2c_cfg.bf.core_en = 1;
+ writel(i2c_cfg.wrd, ®s->i2c_cfg);
+}
+
+static int ca_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
+{
+ struct ca_i2c *priv = dev_get_priv(bus);
+ int i2c_spd;
+
+ if (speed >= I2C_SPEED_FAST_PLUS_RATE) {
+ i2c_spd = IC_SPEED_MODE_FAST_PLUS;
+ priv->speed = I2C_SPEED_FAST_PLUS_RATE;
+ } else if (speed >= I2C_SPEED_FAST_RATE) {
+ i2c_spd = IC_SPEED_MODE_FAST;
+ priv->speed = I2C_SPEED_FAST_RATE;
+ } else {
+ i2c_spd = IC_SPEED_MODE_STANDARD;
+ priv->speed = I2C_SPEED_STANDARD_RATE;
+ }
+
+ set_speed(priv->regs, i2c_spd);
+
+ return 0;
+}
+
+static int ca_i2c_get_bus_speed(struct udevice *bus)
+{
+ struct ca_i2c *priv = dev_get_priv(bus);
+
+ return priv->speed;
+}
+
+static void ca_i2c_init(struct i2c_regs *regs)
+{
+ union ca_biw_cfg i2c_cfg;
+
+ i2c_cfg.wrd = readl(®s->i2c_cfg);
+ i2c_cfg.bf.core_en = 0;
+ i2c_cfg.bf.biw_soft_reset = 1;
+ writel(i2c_cfg.wrd, ®s->i2c_cfg);
+ mdelay(10);
+ i2c_cfg.bf.biw_soft_reset = 0;
+ writel(i2c_cfg.wrd, ®s->i2c_cfg);
+
+ set_speed(regs, IC_SPEED_MODE_STANDARD);
+
+ i2c_cfg.wrd = readl(®s->i2c_cfg);
+ i2c_cfg.bf.core_en = 1;
+ writel(i2c_cfg.wrd, ®s->i2c_cfg);
+}
+
+static int i2c_wait_complete(struct i2c_regs *regs)
+{
+ union ca_biw_ctrl i2c_ctrl;
+ unsigned long start_time_bb = get_timer(0);
+
+ i2c_ctrl.wrd = readl(®s->i2c_ctrl);
+
+ while (i2c_ctrl.bf.biwdone == 0) {
+ i2c_ctrl.wrd = readl(®s->i2c_ctrl);
+
+ if (get_timer(start_time_bb) >
+ (unsigned long)(I2C_BYTE_TO_BB)) {
+ printf("%s not done!!!\n", __func__);
+ return -ETIMEDOUT;
+ }
+ }
+
+ /* Clear done bit */
+ writel(i2c_ctrl.wrd, ®s->i2c_ctrl);
+
+ return 0;
+}
+
+static void i2c_setaddress(struct i2c_regs *regs, unsigned int i2c_addr,
+ int write_read)
+{
+ writel(i2c_addr | write_read, ®s->i2c_txr);
+
+ writel(BIW_CTRL_START | BIW_CTRL_WRITE,
+ ®s->i2c_ctrl);
+
+ i2c_wait_complete(regs);
+}
+
+static int i2c_wait_for_bus_busy(struct i2c_regs *regs)
+{
+ union ca_biw_ack i2c_ack;
+ unsigned long start_time_bb = get_timer(0);
+
+ i2c_ack.wrd = readl(®s->i2c_ack);
+
+ while (i2c_ack.bf.biw_busy) {
+ i2c_ack.wrd = readl(®s->i2c_ack);
+
+ if (get_timer(start_time_bb) >
+ (unsigned long)(I2C_BYTE_TO_BB)) {
+ printf("%s: timeout!\n", __func__);
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
+
+static int i2c_xfer_init(struct i2c_regs *regs, uint8_t chip, uint addr,
+ int alen, int write_read)
+{
+ int addr_len = alen;
+
+ if (i2c_wait_for_bus_busy(regs))
+ return 1;
+
+ /* First cycle must write addr + offset */
+ chip = ((chip & 0x7F) << 1);
+ if (alen == 0 && write_read == I2C_CMD_RD)
+ i2c_setaddress(regs, chip, I2C_CMD_RD);
+ else
+ i2c_setaddress(regs, chip, I2C_CMD_WT);
+
+ while (alen) {
+ alen--;
+ writel(addr, ®s->i2c_txr);
+ if (write_read == I2C_CMD_RD)
+ writel(BIW_CTRL_WRITE | BIW_CTRL_STOP,
+ ®s->i2c_ctrl);
+ else
+ writel(BIW_CTRL_WRITE, ®s->i2c_ctrl);
+ i2c_wait_complete(regs);
+ }
+
+ /* Send address again with Read flag if it's read command */
+ if (write_read == I2C_CMD_RD && addr_len > 0)
+ i2c_setaddress(regs, chip, I2C_CMD_RD);
+
+ return 0;
+}
+
+static int i2c_xfer_finish(struct i2c_regs *regs)
+{
+ /* Dummy read makes bus free */
+ writel(BIW_CTRL_READ | BIW_CTRL_STOP, ®s->i2c_ctrl);
+ i2c_wait_complete(regs);
+
+ if (i2c_wait_for_bus_busy(regs)) {
+ printf("Timed out waiting for bus\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static int ca_i2c_read(struct i2c_regs *regs, uint8_t chip, uint addr,
+ int alen, uint8_t *buffer, int len)
+{
+ unsigned long start_time_rx;
+ int rc = 0;
+
+ rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_RD);
+ if (rc)
+ return rc;
+
+ start_time_rx = get_timer(0);
+ while (len) {
+ /* ACK_IN is ack value to send during read.
+ * ack high only on the very last byte!
+ */
+ if (len == 1)
+ writel(BIW_CTRL_READ | BIW_CTRL_ACK_IN | BIW_CTRL_STOP,
+ ®s->i2c_ctrl);
+ else
+ writel(BIW_CTRL_READ, ®s->i2c_ctrl);
+
+ rc = i2c_wait_complete(regs);
+ udelay(1);
+
+ if (rc == 0) {
+ *buffer++ =
+ (uchar) readl(®s->i2c_rxr);
+ len--;
+ start_time_rx = get_timer(0);
+
+ } else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
+ return -ETIMEDOUT;
+ }
+ }
+ i2c_xfer_finish(regs);
+ return rc;
+}
+
+static int ca_i2c_write(struct i2c_regs *regs, uint8_t chip, uint addr,
+ int alen, uint8_t *buffer, int len)
+{
+ int rc, nb = len;
+ unsigned long start_time_tx;
+
+ rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_WT);
+ if (rc)
+ return rc;
+
+ start_time_tx = get_timer(0);
+ while (len) {
+ writel(*buffer, ®s->i2c_txr);
+ if (len == 1)
+ writel(BIW_CTRL_WRITE | BIW_CTRL_STOP,
+ ®s->i2c_ctrl);
+ else
+ writel(BIW_CTRL_WRITE, ®s->i2c_ctrl);
+
+ rc = i2c_wait_complete(regs);
+
+ if (rc == 0) {
+ len--;
+ buffer++;
+ start_time_tx = get_timer(0);
+ } else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
+
+static int ca_i2c_probe_chip(struct udevice *bus, uint chip_addr,
+ uint chip_flags)
+{
+ struct ca_i2c *priv = dev_get_priv(bus);
+ int ret;
+ u32 tmp;
+
+ /* Try to read the first location of the chip */
+ ret = ca_i2c_read(priv->regs, chip_addr, 0, 1, (uchar *)&tmp, 1);
+ if (ret)
+ ca_i2c_init(priv->regs);
+
+ return ret;
+}
+
+static int ca_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
+{
+ struct ca_i2c *priv = 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 = ca_i2c_read(priv->regs, msg->addr, 0, 0,
+ msg->buf, msg->len);
+ else
+ ret = ca_i2c_write(priv->regs, msg->addr, 0, 0,
+ msg->buf, msg->len);
+
+ if (ret) {
+ printf("i2c_xfer: %s error\n",
+ msg->flags & I2C_M_RD ? "read" : "write");
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static const struct dm_i2c_ops ca_i2c_ops = {
+ .xfer = ca_i2c_xfer,
+ .probe_chip = ca_i2c_probe_chip,
+ .set_bus_speed = ca_i2c_set_bus_speed,
+ .get_bus_speed = ca_i2c_get_bus_speed,
+};
+
+static const struct udevice_id ca_i2c_ids[] = {
+ { .compatible = "cortina,ca-i2c", },
+ { }
+};
+
+static int ca_i2c_probe(struct udevice *bus)
+{
+ struct ca_i2c *priv = dev_get_priv(bus);
+
+ ca_i2c_init(priv->regs);
+
+ return 0;
+}
+
+static int ca_i2c_ofdata_to_platdata(struct udevice *bus)
+{
+ struct ca_i2c *priv = dev_get_priv(bus);
+
+ priv->regs = map_sysmem(dev_read_addr(bus), sizeof(struct i2c_regs));
+ if (!priv->regs) {
+ printf("I2C: base address is invalid\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+U_BOOT_DRIVER(i2c_cortina) = {
+ .name = "i2c_cortina",
+ .id = UCLASS_I2C,
+ .of_match = ca_i2c_ids,
+ .ofdata_to_platdata = ca_i2c_ofdata_to_platdata,
+ .probe = ca_i2c_probe,
+ .priv_auto_alloc_size = sizeof(struct ca_i2c),
+ .ops = &ca_i2c_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+};
projects / platform / kernel / u-boot.git / commitdiff