i2c: add Tegra186 BPMP driver

On Tegra186, some I2C controllers are directly controlled by the main CPU,
whereas others are controlled by the BPMP, and can only be accessed by the
main CPU via IPC requests to the BPMP. This driver covers the latter case.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>

1 files changed, 129 insertions, 0 deletions

diff --git a/drivers/i2c/tegra186_bpmp_i2c.c b/drivers/i2c/tegra186_bpmp_i2c.c
new file mode 100644
index 0000000..88e8413
--- /dev/null
+++ b/drivers/i2c/tegra186_bpmp_i2c.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <i2c.h>
+#include <misc.h>
+#include <asm/arch-tegra/bpmp_abi.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct tegra186_bpmp_i2c {
+	uint32_t bpmp_bus_id;
+};
+
+static inline void serialize_u16(uint8_t **p, uint16_t val)
+{
+	(*p)[0] = val & 0xff;
+	(*p)[1] = val >> 8;
+	(*p) += 2;
+}
+
+/* These just happen to have the same values as I2C_M_* and SERIALI2C_* */
+#define SUPPORTED_FLAGS \
+	(I2C_M_TEN | \
+	I2C_M_RD | \
+	I2C_M_STOP | \
+	I2C_M_NOSTART | \
+	I2C_M_REV_DIR_ADDR | \
+	I2C_M_IGNORE_NAK | \
+	I2C_M_NO_RD_ACK | \
+	I2C_M_RECV_LEN)
+
+static int tegra186_bpmp_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
+				  int nmsgs)
+{
+	struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
+	struct mrq_i2c_request req;
+	struct mrq_i2c_response resp;
+	uint8_t *p;
+	int left, i, ret;
+
+	req.cmd = CMD_I2C_XFER;
+	req.xfer.bus_id = priv->bpmp_bus_id;
+	p = &req.xfer.data_buf[0];
+	left = ARRAY_SIZE(req.xfer.data_buf);
+	for (i = 0; i < nmsgs; i++) {
+		int len = 6;
+		if (!(msg[i].flags & I2C_M_RD))
+			len += msg[i].len;
+		if ((len >= BIT(16)) || (len > left))
+			return -ENOSPC;
+
+		if (msg[i].flags & ~SUPPORTED_FLAGS)
+			return -EINVAL;
+
+		serialize_u16(&p, msg[i].addr);
+		serialize_u16(&p, msg[i].flags);
+		serialize_u16(&p, msg[i].len);
+		if (!(msg[i].flags & I2C_M_RD)) {
+			memcpy(p, msg[i].buf, msg[i].len);
+			p += msg[i].len;
+		}
+	}
+	req.xfer.data_size = p - &req.xfer.data_buf[0];
+
+	ret = misc_call(dev->parent, MRQ_I2C, &req, sizeof(req), &resp,
+			sizeof(resp));
+	if (ret < 0)
+		return ret;
+
+	p = &resp.xfer.data_buf[0];
+	left = resp.xfer.data_size;
+	if (left > ARRAY_SIZE(resp.xfer.data_buf))
+		return -EINVAL;
+	for (i = 0; i < nmsgs; i++) {
+		if (msg[i].flags & I2C_M_RD) {
+			memcpy(msg[i].buf, p, msg[i].len);
+			p += msg[i].len;
+		}
+	}
+
+	return 0;
+}
+
+static int tegra186_bpmp_i2c_probe(struct udevice *dev)
+{
+	struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
+	int ret;
+	struct fdtdec_phandle_args args;
+
+	ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev->of_offset,
+					     "nvidia,bpmp", NULL, 0, 0, &args);
+	if (ret < 0) {
+		debug("%s: fdtdec_parse_phandle_with_args() failed: %d\n",
+		      __func__, ret);
+		return ret;
+	}
+
+	priv->bpmp_bus_id = fdtdec_get_uint(gd->fdt_blob, dev->of_offset,
+					    "nvidia,bpmp-bus-id", U32_MAX);
+	if (priv->bpmp_bus_id == U32_MAX) {
+		debug("%s: could not parse nvidia,bpmp-bus-id\n", __func__);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static const struct dm_i2c_ops tegra186_bpmp_i2c_ops = {
+	.xfer = tegra186_bpmp_i2c_xfer,
+};
+
+static const struct udevice_id tegra186_bpmp_i2c_ids[] = {
+	{ .compatible = "nvidia,tegra186-bpmp-i2c" },
+	{ }
+};
+
+U_BOOT_DRIVER(i2c_gpio) = {
+	.name	= "tegra186_bpmp_i2c",
+	.id	= UCLASS_I2C,
+	.of_match = tegra186_bpmp_i2c_ids,
+	.probe	= tegra186_bpmp_i2c_probe,
+	.priv_auto_alloc_size = sizeof(struct tegra186_bpmp_i2c),
+	.ops	= &tegra186_bpmp_i2c_ops,
+};