[U-Boot] [PATCH 5/6] i2c: designware_i2c: Add DM support

[Stefan Roese]

This patch adds DM support to the designware I2C driver. It currently
supports DM and the legacy I2C support. The legacy support should be
removed, once all platforms using it have DM enabled.

Signed-off-by: Stefan Roese <sr at denx.de>
Cc: Simon Glass <sjg at chromium.org>
Cc: Bin Meng <bmeng.cn at gmail.com>
Cc: Marek Vasut <marex at denx.de>
Cc: Heiko Schocher <hs at denx.de>
---
 drivers/i2c/designware_i2c.c | 149 ++++++++++++++++++++++++++++++++++++-------
 1 file changed, 126 insertions(+), 23 deletions(-)

diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index e51e6de..4e5340d 100644
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -6,10 +6,15 @@
  */
 
 #include <common.h>
+#include <dm.h>
 #include <i2c.h>
 #include <asm/io.h>
 #include "designware_i2c.h"
 
+struct dw_i2c {
+	struct i2c_regs *regs;
+};
+
 static void dw_i2c_enable(struct i2c_regs *i2c_base, bool enable)
 {
 	int timeout = 100;
@@ -293,6 +298,36 @@ static int __dw_i2c_write(struct i2c_regs *i2c_base, u8 dev, uint addr,
 	return i2c_xfer_finish(i2c_base);
 }
 
+/*
+ * 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, 0);
+
+	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);
+	writel(IC_STOP_DET, &i2c_base->ic_intr_mask);
+#ifndef CONFIG_DM_I2C
+	__dw_i2c_set_bus_speed(i2c_base, speed);
+	writel(slaveaddr, &i2c_base->ic_sar);
+#endif
+
+	/* Enable i2c */
+	dw_i2c_enable(i2c_base, 1);
+}
+
+#ifndef CONFIG_DM_I2C
+/*
+ * 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) {
@@ -324,30 +359,9 @@ static unsigned int dw_i2c_set_bus_speed(struct i2c_adapter *adap,
 	return __dw_i2c_set_bus_speed(i2c_get_base(adap), speed);
 }
 
-/*
- * 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)
+static void dw_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
 {
-	struct i2c_regs *i2c_base = i2c_get_base(adap);
-
-	/* Disable i2c */
-	dw_i2c_enable(i2c_base, 0);
-
-	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 */
-	dw_i2c_enable(i2c_base, 1);
+	__dw_i2c_init(i2c_get_base(adap), speed, slaveaddr);
 }
 
 static int dw_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr,
@@ -402,3 +416,92 @@ 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, 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);
+
+	/* Save base address from device-tree */
+	priv->regs = (struct i2c_regs *)dev_get_addr(bus);
+
+	__dw_i2c_init(priv->regs, 0, 0);
+
+	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,
+	.probe	= designware_i2c_probe,
+	.priv_auto_alloc_size = sizeof(struct dw_i2c),
+	.ops	= &designware_i2c_ops,
+};
+
+#endif /* CONFIG_DM_I2C */
-- 
2.7.3