[U-Boot] [PATCH 4/7] i2c: add Tegra186 BPMP driver

[Heiko Schocher]

Hello Stephen,

Am 29.07.2016 um 21:15 schrieb Stephen Warren:
> From: Stephen Warren <swarren at nvidia.com>
>
> 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 at nvidia.com>
> ---
>   drivers/i2c/Kconfig             |  10 ++++
>   drivers/i2c/Makefile            |   1 +
>   drivers/i2c/tegra186_bpmp_i2c.c | 129 ++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 140 insertions(+)
>   create mode 100644 drivers/i2c/tegra186_bpmp_i2c.c

Reviewed-by: Heiko Schocher <hs at denx.de>

bye,
Heiko
>
> diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
> index 6e22bbadff2d..68d3956e473c 100644
> --- a/drivers/i2c/Kconfig
> +++ b/drivers/i2c/Kconfig
> @@ -154,6 +154,16 @@ config SYS_I2C_UNIPHIER_F
>   	  Support for UniPhier FIFO-builtin I2C controller driver.
>   	  This I2C controller is used on PH1-Pro4 or newer UniPhier SoCs.
>
> +config TEGRA186_BPMP_I2C
> +	bool "Enable Tegra186 BPMP-based I2C driver"
> +	depends on TEGRA186_BPMP
> +	help
> +	  Support for Tegra I2C controllers managed by the BPMP (Boot and
> +	  Power Management Processor). 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.
> +
>   source "drivers/i2c/muxes/Kconfig"
>
>   endmenu
> diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
> index 167424db9820..97b6bedde822 100644
> --- a/drivers/i2c/Makefile
> +++ b/drivers/i2c/Makefile
> @@ -41,5 +41,6 @@ obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o
>   obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o
>   obj-$(CONFIG_SYS_I2C_UNIPHIER_F) += i2c-uniphier-f.o
>   obj-$(CONFIG_SYS_I2C_ZYNQ) += zynq_i2c.o
> +obj-$(CONFIG_TEGRA186_BPMP_I2C) += tegra186_bpmp_i2c.o
>
>   obj-$(CONFIG_I2C_MUX) += muxes/
> diff --git a/drivers/i2c/tegra186_bpmp_i2c.c b/drivers/i2c/tegra186_bpmp_i2c.c
> new file mode 100644
> index 000000000000..d3b3edffb53f
> --- /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 <asm/arch-tegra/bpmp_abi.h>
> +#include <asm/arch-tegra/tegra186_bpmp.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 = tegra186_bpmp_call(dev->parent, MRQ_I2C,
> +				 &req, sizeof(req), &resp, sizeof(resp));
> +	if (ret)
> +		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,
> +};
>

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