[PATCH V3 1/4] i2c: busses: add SLIMpro I2C device driver on APM X-Gene platform

Feng Kan
2015-04-23T18:07:07Z

Add SLIMpro I2C device driver on APM X-Gene platform. This I2C
device driver use the SLIMpro Mailbox driver to tunnel message to
the SLIMpro coprocessor to do the work of accessing I2C components.

Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Hieu Le <hnle@apm.com>
---
drivers/i2c/busses/Kconfig | 9 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-xgene-slimpro.c | 459 +++++++++++++++++++++++++++++++++
3 files changed, 469 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-xgene-slimpro.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 22da9c2..1ac07d0 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1082,6 +1082,15 @@ 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
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 3638feb..9cf9c4b 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -107,6 +107,7 @@ 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
diff --git a/drivers/i2c/busses/i2c-xgene-slimpro.c b/drivers/i2c/busses/i2c-xgene-slimpro.c
new file mode 100644
index 0000000..afe4cf2
--- /dev/null
+++ b/drivers/i2c/busses/i2c-xgene-slimpro.c
@@ -0,0 +1,459 @@
+/*
+ * 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/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_id[] = {
+ {.compatible = "apm,xgene-slimpro-i2c" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, xgene_slimpro_i2c_dt_ids);
+
+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_id)
+ },
+};
+
+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");
--
1.9.1