i2c: add SLIMpro I2C device driver on APM X-Gene platform (f6505fba) · Commits · 戴 / test

Documentation/devicetree/bindings/i2c/i2c-xgene-slimpro.txt

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+15 −0

Original line number	Diff line number	Diff line
		APM X-Gene SLIMpro Mailbox I2C Driver

		An I2C controller accessed over the "SLIMpro" mailbox.

		Required properties :

		- compatible : should be "apm,xgene-slimpro-i2c"
		- mboxes : use the label reference for the mailbox as the first parameter.
		The second parameter is the channel number.

		Example :
		i2cslimpro {
		compatible = "apm,xgene-slimpro-i2c";
		mboxes = <&mailbox 0>;
		};

drivers/i2c/busses/Kconfig

+9 −0

Original line number	Diff line number	Diff line
		@@ -1110,6 +1110,15 @@ config I2C_CROS_EC_TUNNEL
		connected there. This will work whatever the interface used to
		talk to the EC (SPI, I2C or LPC).

		config I2C_XGENE_SLIMPRO
		tristate "APM X-Gene SoC I2C SLIMpro devices support"
		depends on ARCH_XGENE && MAILBOX
		help
		Enable I2C bus access using the APM X-Gene SoC SLIMpro
		co-processor. The I2C device access the I2C bus via the X-Gene
		to SLIMpro (On chip coprocessor) mailbox mechanism.
		If unsure, say N.

		config SCx200_ACB
		tristate "Geode ACCESS.bus support"
		depends on X86_32 && PCI

drivers/i2c/busses/Makefile

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Original line number	Diff line number	Diff line
		@@ -110,6 +110,7 @@ obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o
		obj-$(CONFIG_I2C_OPAL) += i2c-opal.o
		obj-$(CONFIG_I2C_PCA_ISA) += i2c-pca-isa.o
		obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o
		obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o
		obj-$(CONFIG_SCx200_ACB) += scx200_acb.o

		ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG

drivers/i2c/busses/i2c-xgene-slimpro.c

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Original line number	Diff line number	Diff line
		/*
		* X-Gene SLIMpro I2C Driver
		*
		* Copyright (c) 2014, Applied Micro Circuits Corporation
		* Author: Feng Kan <fkan@apm.com>
		* Author: Hieu Le <hnle@apm.com>
		*
		* This program is free software; you can redistribute it and/or
		* modify it under the terms of the GNU General Public License as
		* published by the Free Software Foundation; either version 2 of
		* the License, or (at your option) any later version.
		*
		* This program is distributed in the hope that it will be useful,
		* but WITHOUT ANY WARRANTY; without even the implied warranty of
		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
		* GNU General Public License for more details.
		*
		* You should have received a copy of the GNU General Public License
		* along with this program; if not, see <http://www.gnu.org/licenses/>.
		*
		* This driver provides support for X-Gene SLIMpro I2C device access
		* using the APM X-Gene SLIMpro mailbox driver.
		*
		*/
		#include <linux/acpi.h>
		#include <linux/dma-mapping.h>
		#include <linux/i2c.h>
		#include <linux/interrupt.h>
		#include <linux/mailbox_client.h>
		#include <linux/module.h>
		#include <linux/of.h>
		#include <linux/platform_device.h>
		#include <linux/version.h>

		#define MAILBOX_OP_TIMEOUT 1000 /* Operation time out in ms */
		#define MAILBOX_I2C_INDEX 0
		#define SLIMPRO_IIC_BUS 1 /* Use I2C bus 1 only */

		#define SMBUS_CMD_LEN 1
		#define BYTE_DATA 1
		#define WORD_DATA 2
		#define BLOCK_DATA 3

		#define SLIMPRO_IIC_I2C_PROTOCOL 0
		#define SLIMPRO_IIC_SMB_PROTOCOL 1

		#define SLIMPRO_IIC_READ 0
		#define SLIMPRO_IIC_WRITE 1

		#define IIC_SMB_WITHOUT_DATA_LEN 0
		#define IIC_SMB_WITH_DATA_LEN 1

		#define SLIMPRO_DEBUG_MSG 0
		#define SLIMPRO_MSG_TYPE_SHIFT 28
		#define SLIMPRO_DBG_SUBTYPE_I2C1READ 4
		#define SLIMPRO_DBGMSG_TYPE_SHIFT 24
		#define SLIMPRO_DBGMSG_TYPE_MASK 0x0F000000U
		#define SLIMPRO_IIC_DEV_SHIFT 23
		#define SLIMPRO_IIC_DEV_MASK 0x00800000U
		#define SLIMPRO_IIC_DEVID_SHIFT 13
		#define SLIMPRO_IIC_DEVID_MASK 0x007FE000U
		#define SLIMPRO_IIC_RW_SHIFT 12
		#define SLIMPRO_IIC_RW_MASK 0x00001000U
		#define SLIMPRO_IIC_PROTO_SHIFT 11
		#define SLIMPRO_IIC_PROTO_MASK 0x00000800U
		#define SLIMPRO_IIC_ADDRLEN_SHIFT 8
		#define SLIMPRO_IIC_ADDRLEN_MASK 0x00000700U
		#define SLIMPRO_IIC_DATALEN_SHIFT 0
		#define SLIMPRO_IIC_DATALEN_MASK 0x000000FFU

		/*
		* SLIMpro I2C message encode
		*
		* dev - Controller number (0-based)
		* chip - I2C chip address
		* op - SLIMPRO_IIC_READ or SLIMPRO_IIC_WRITE
		* proto - SLIMPRO_IIC_SMB_PROTOCOL or SLIMPRO_IIC_I2C_PROTOCOL
		* addrlen - Length of the address field
		* datalen - Length of the data field
		*/
		#define SLIMPRO_IIC_ENCODE_MSG(dev, chip, op, proto, addrlen, datalen) \
		((SLIMPRO_DEBUG_MSG << SLIMPRO_MSG_TYPE_SHIFT) \| \
		((SLIMPRO_DBG_SUBTYPE_I2C1READ << SLIMPRO_DBGMSG_TYPE_SHIFT) & \
		SLIMPRO_DBGMSG_TYPE_MASK) \| \
		((dev << SLIMPRO_IIC_DEV_SHIFT) & SLIMPRO_IIC_DEV_MASK) \| \
		((chip << SLIMPRO_IIC_DEVID_SHIFT) & SLIMPRO_IIC_DEVID_MASK) \| \
		((op << SLIMPRO_IIC_RW_SHIFT) & SLIMPRO_IIC_RW_MASK) \| \
		((proto << SLIMPRO_IIC_PROTO_SHIFT) & SLIMPRO_IIC_PROTO_MASK) \| \
		((addrlen << SLIMPRO_IIC_ADDRLEN_SHIFT) & SLIMPRO_IIC_ADDRLEN_MASK) \| \
		((datalen << SLIMPRO_IIC_DATALEN_SHIFT) & SLIMPRO_IIC_DATALEN_MASK))

		/*
		* Encode for upper address for block data
		*/
		#define SLIMPRO_IIC_ENCODE_FLAG_BUFADDR 0x80000000
		#define SLIMPRO_IIC_ENCODE_FLAG_WITH_DATA_LEN(a) ((u32) (((a) << 30) \
		& 0x40000000))
		#define SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(a) ((u32) (((a) >> 12) \
		& 0x3FF00000))
		#define SLIMPRO_IIC_ENCODE_ADDR(a) ((a) & 0x000FFFFF)

		struct slimpro_i2c_dev {
		struct i2c_adapter adapter;
		struct device *dev;
		struct mbox_chan *mbox_chan;
		struct mbox_client mbox_client;
		struct completion rd_complete;
		u8 dma_buffer[I2C_SMBUS_BLOCK_MAX];
		u32 *resp_msg;
		};

		#define to_slimpro_i2c_dev(cl) \
		container_of(cl, struct slimpro_i2c_dev, mbox_client)

		static void slimpro_i2c_rx_cb(struct mbox_client cl, void mssg)
		{
		struct slimpro_i2c_dev *ctx = to_slimpro_i2c_dev(cl);

		/*
		* Response message format:
		* mssg[0] is the return code of the operation
		* mssg[1] is the first data word
		* mssg[2] is NOT used
		*/
		if (ctx->resp_msg)
		ctx->resp_msg = ((u32 )mssg)[1];

		if (ctx->mbox_client.tx_block)
		complete(&ctx->rd_complete);
		}

		static int start_i2c_msg_xfer(struct slimpro_i2c_dev *ctx)
		{
		if (ctx->mbox_client.tx_block) {
		if (!wait_for_completion_timeout(&ctx->rd_complete,
		msecs_to_jiffies(MAILBOX_OP_TIMEOUT)))
		return -ETIMEDOUT;
		}

		/* Check of invalid data or no device */
		if (*ctx->resp_msg == 0xffffffff)
		return -ENODEV;

		return 0;
		}

		static int slimpro_i2c_rd(struct slimpro_i2c_dev *ctx, u32 chip,
		u32 addr, u32 addrlen, u32 protocol,
		u32 readlen, u32 *data)
		{
		u32 msg[3];
		int rc;

		msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip,
		SLIMPRO_IIC_READ, protocol, addrlen, readlen);
		msg[1] = SLIMPRO_IIC_ENCODE_ADDR(addr);
		msg[2] = 0;
		ctx->resp_msg = data;
		rc = mbox_send_message(ctx->mbox_chan, &msg);
		if (rc < 0)
		goto err;

		rc = start_i2c_msg_xfer(ctx);
		err:
		ctx->resp_msg = NULL;
		return rc;
		}

		static int slimpro_i2c_wr(struct slimpro_i2c_dev *ctx, u32 chip,
		u32 addr, u32 addrlen, u32 protocol, u32 writelen,
		u32 data)
		{
		u32 msg[3];
		int rc;

		msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip,
		SLIMPRO_IIC_WRITE, protocol, addrlen, writelen);
		msg[1] = SLIMPRO_IIC_ENCODE_ADDR(addr);
		msg[2] = data;
		ctx->resp_msg = msg;

		rc = mbox_send_message(ctx->mbox_chan, &msg);
		if (rc < 0)
		goto err;

		rc = start_i2c_msg_xfer(ctx);
		err:
		ctx->resp_msg = NULL;
		return rc;
		}

		static int slimpro_i2c_blkrd(struct slimpro_i2c_dev *ctx, u32 chip, u32 addr,
		u32 addrlen, u32 protocol, u32 readlen,
		u32 with_data_len, void *data)
		{
		dma_addr_t paddr;
		u32 msg[3];
		int rc;

		paddr = dma_map_single(ctx->dev, ctx->dma_buffer, readlen, DMA_FROM_DEVICE);
		rc = dma_mapping_error(ctx->dev, paddr);
		if (rc) {
		dev_err(&ctx->adapter.dev, "Error in mapping dma buffer %p\n",
		ctx->dma_buffer);
		goto err;
		}

		msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip, SLIMPRO_IIC_READ,
		protocol, addrlen, readlen);
		msg[1] = SLIMPRO_IIC_ENCODE_FLAG_BUFADDR \|
		SLIMPRO_IIC_ENCODE_FLAG_WITH_DATA_LEN(with_data_len) \|
		SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(paddr) \|
		SLIMPRO_IIC_ENCODE_ADDR(addr);
		msg[2] = (u32)paddr;
		ctx->resp_msg = msg;

		rc = mbox_send_message(ctx->mbox_chan, &msg);
		if (rc < 0)
		goto err_unmap;

		rc = start_i2c_msg_xfer(ctx);

		/* Copy to destination */
		memcpy(data, ctx->dma_buffer, readlen);

		err_unmap:
		dma_unmap_single(ctx->dev, paddr, readlen, DMA_FROM_DEVICE);
		err:
		ctx->resp_msg = NULL;
		return rc;
		}

		static int slimpro_i2c_blkwr(struct slimpro_i2c_dev *ctx, u32 chip,
		u32 addr, u32 addrlen, u32 protocol, u32 writelen,
		void *data)
		{
		dma_addr_t paddr;
		u32 msg[3];
		int rc;

		memcpy(ctx->dma_buffer, data, writelen);
		paddr = dma_map_single(ctx->dev, ctx->dma_buffer, writelen,
		DMA_TO_DEVICE);
		rc = dma_mapping_error(ctx->dev, paddr);
		if (rc) {
		dev_err(&ctx->adapter.dev, "Error in mapping dma buffer %p\n",
		ctx->dma_buffer);
		goto err;
		}

		msg[0] = SLIMPRO_IIC_ENCODE_MSG(SLIMPRO_IIC_BUS, chip, SLIMPRO_IIC_WRITE,
		protocol, addrlen, writelen);
		msg[1] = SLIMPRO_IIC_ENCODE_FLAG_BUFADDR \|
		SLIMPRO_IIC_ENCODE_UPPER_BUFADDR(paddr) \|
		SLIMPRO_IIC_ENCODE_ADDR(addr);
		msg[2] = (u32)paddr;
		ctx->resp_msg = msg;

		if (ctx->mbox_client.tx_block)
		reinit_completion(&ctx->rd_complete);

		rc = mbox_send_message(ctx->mbox_chan, &msg);
		if (rc < 0)
		goto err_unmap;

		rc = start_i2c_msg_xfer(ctx);

		err_unmap:
		dma_unmap_single(ctx->dev, paddr, writelen, DMA_TO_DEVICE);
		err:
		ctx->resp_msg = NULL;
		return rc;
		}

		static int xgene_slimpro_i2c_xfer(struct i2c_adapter *adap, u16 addr,
		unsigned short flags, char read_write,
		u8 command, int size,
		union i2c_smbus_data *data)
		{
		struct slimpro_i2c_dev *ctx = i2c_get_adapdata(adap);
		int ret = -EOPNOTSUPP;
		u32 val;

		switch (size) {
		case I2C_SMBUS_BYTE:
		if (read_write == I2C_SMBUS_READ) {
		ret = slimpro_i2c_rd(ctx, addr, 0, 0,
		SLIMPRO_IIC_SMB_PROTOCOL,
		BYTE_DATA, &val);
		data->byte = val;
		} else {
		ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
		SLIMPRO_IIC_SMB_PROTOCOL,
		0, 0);
		}
		break;
		case I2C_SMBUS_BYTE_DATA:
		if (read_write == I2C_SMBUS_READ) {
		ret = slimpro_i2c_rd(ctx, addr, command, SMBUS_CMD_LEN,
		SLIMPRO_IIC_SMB_PROTOCOL,
		BYTE_DATA, &val);
		data->byte = val;
		} else {
		val = data->byte;
		ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
		SLIMPRO_IIC_SMB_PROTOCOL,
		BYTE_DATA, val);
		}
		break;
		case I2C_SMBUS_WORD_DATA:
		if (read_write == I2C_SMBUS_READ) {
		ret = slimpro_i2c_rd(ctx, addr, command, SMBUS_CMD_LEN,
		SLIMPRO_IIC_SMB_PROTOCOL,
		WORD_DATA, &val);
		data->word = val;
		} else {
		val = data->word;
		ret = slimpro_i2c_wr(ctx, addr, command, SMBUS_CMD_LEN,
		SLIMPRO_IIC_SMB_PROTOCOL,
		WORD_DATA, val);
		}
		break;
		case I2C_SMBUS_BLOCK_DATA:
		if (read_write == I2C_SMBUS_READ) {
		ret = slimpro_i2c_blkrd(ctx, addr, command,
		SMBUS_CMD_LEN,
		SLIMPRO_IIC_SMB_PROTOCOL,
		I2C_SMBUS_BLOCK_MAX + 1,
		IIC_SMB_WITH_DATA_LEN,
		&data->block[0]);

		} else {
		ret = slimpro_i2c_blkwr(ctx, addr, command,
		SMBUS_CMD_LEN,
		SLIMPRO_IIC_SMB_PROTOCOL,
		data->block[0] + 1,
		&data->block[0]);
		}
		break;
		case I2C_SMBUS_I2C_BLOCK_DATA:
		if (read_write == I2C_SMBUS_READ) {
		ret = slimpro_i2c_blkrd(ctx, addr,
		command,
		SMBUS_CMD_LEN,
		SLIMPRO_IIC_I2C_PROTOCOL,
		I2C_SMBUS_BLOCK_MAX,
		IIC_SMB_WITHOUT_DATA_LEN,
		&data->block[1]);
		} else {
		ret = slimpro_i2c_blkwr(ctx, addr, command,
		SMBUS_CMD_LEN,
		SLIMPRO_IIC_I2C_PROTOCOL,
		data->block[0],
		&data->block[1]);
		}
		break;
		default:
		break;
		}
		return ret;
		}

		/*
		* Return list of supported functionality.
		*/
		static u32 xgene_slimpro_i2c_func(struct i2c_adapter *adapter)
		{
		return I2C_FUNC_SMBUS_BYTE \|
		I2C_FUNC_SMBUS_BYTE_DATA \|
		I2C_FUNC_SMBUS_WORD_DATA \|
		I2C_FUNC_SMBUS_BLOCK_DATA \|
		I2C_FUNC_SMBUS_I2C_BLOCK;
		}

		static struct i2c_algorithm xgene_slimpro_i2c_algorithm = {
		.smbus_xfer = xgene_slimpro_i2c_xfer,
		.functionality = xgene_slimpro_i2c_func,
		};

		static int __init xgene_slimpro_i2c_probe(struct platform_device *pdev)
		{
		struct slimpro_i2c_dev *ctx;
		struct i2c_adapter *adapter;
		struct mbox_client *cl;
		int rc;

		ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
		if (!ctx)
		return -ENOMEM;

		ctx->dev = &pdev->dev;
		platform_set_drvdata(pdev, ctx);
		cl = &ctx->mbox_client;

		/* Request mailbox channel */
		cl->dev = &pdev->dev;
		cl->rx_callback = slimpro_i2c_rx_cb;
		cl->tx_block = true;
		init_completion(&ctx->rd_complete);
		cl->tx_tout = MAILBOX_OP_TIMEOUT;
		cl->knows_txdone = false;
		ctx->mbox_chan = mbox_request_channel(cl, MAILBOX_I2C_INDEX);
		if (IS_ERR(ctx->mbox_chan)) {
		dev_err(&pdev->dev, "i2c mailbox channel request failed\n");
		return PTR_ERR(ctx->mbox_chan);
		}

		rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
		if (rc)
		dev_warn(&pdev->dev, "Unable to set dma mask\n");

		/* Setup I2C adapter */
		adapter = &ctx->adapter;
		snprintf(adapter->name, sizeof(adapter->name), "MAILBOX I2C");
		adapter->algo = &xgene_slimpro_i2c_algorithm;
		adapter->class = I2C_CLASS_HWMON;
		adapter->dev.parent = &pdev->dev;
		i2c_set_adapdata(adapter, ctx);
		rc = i2c_add_adapter(adapter);
		if (rc) {
		dev_err(&pdev->dev, "Adapter registeration failed\n");
		return rc;
		}

		dev_info(&pdev->dev, "Mailbox I2C Adapter registered\n");
		return 0;
		}

		static int xgene_slimpro_i2c_remove(struct platform_device *pdev)
		{
		struct slimpro_i2c_dev *ctx = platform_get_drvdata(pdev);

		i2c_del_adapter(&ctx->adapter);

		mbox_free_channel(ctx->mbox_chan);

		return 0;
		}

		static const struct of_device_id xgene_slimpro_i2c_dt_ids[] = {
		{.compatible = "apm,xgene-slimpro-i2c" },
		{},
		};
		MODULE_DEVICE_TABLE(of, xgene_slimpro_i2c_dt_ids);

		#ifdef CONFIG_ACPI
		static const struct acpi_device_id xgene_slimpro_i2c_acpi_ids[] = {
		{"APMC0D40", 0},
		{}
		};
		MODULE_DEVICE_TABLE(acpi, xgene_slimpro_i2c_acpi_ids);
		#endif

		static struct platform_driver xgene_slimpro_i2c_driver = {
		.probe = xgene_slimpro_i2c_probe,
		.remove = xgene_slimpro_i2c_remove,
		.driver = {
		.name = "xgene-slimpro-i2c",
		.of_match_table = of_match_ptr(xgene_slimpro_i2c_dt_ids),
		.acpi_match_table = ACPI_PTR(xgene_slimpro_i2c_acpi_ids)
		},
		};

		module_platform_driver(xgene_slimpro_i2c_driver);

		MODULE_DESCRIPTION("APM X-Gene SLIMpro I2C driver");
		MODULE_AUTHOR("Feng Kan <fkan@apm.com>");
		MODULE_AUTHOR("Hieu Le <hnle@apm.com>");
		MODULE_LICENSE("GPL");

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