i2c: add SLIMpro I2C device driver on APM X-Gene platform
authorFeng Kan <fkan@apm.com>
Fri, 24 Apr 2015 22:17:50 +0000 (15:17 -0700)
committerWolfram Sang <wsa@the-dreams.de>
Tue, 12 May 2015 20:06:05 +0000 (22:06 +0200)
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>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Documentation/devicetree/bindings/i2c/i2c-xgene-slimpro.txt [new file with mode: 0644]
drivers/i2c/busses/Kconfig
drivers/i2c/busses/Makefile
drivers/i2c/busses/i2c-xgene-slimpro.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/i2c/i2c-xgene-slimpro.txt b/Documentation/devicetree/bindings/i2c/i2c-xgene-slimpro.txt
new file mode 100644 (file)
index 0000000..f6b2c20
--- /dev/null
@@ -0,0 +1,15 @@
+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>;
+       };
index 5c9750ac486cdfa5271daa9b9761d06b5182cc40..1d759c3767e769f0b43da0bbbaf4a2ade26797b0 100644 (file)
@@ -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
index cdf941da91c65ef829b7f658ed41c1f69d5ddf1d..d8093022ee4c062c94fabd7b9c11d191282e68c7 100644 (file)
@@ -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
diff --git a/drivers/i2c/busses/i2c-xgene-slimpro.c b/drivers/i2c/busses/i2c-xgene-slimpro.c
new file mode 100644 (file)
index 0000000..0b33aa2
--- /dev/null
@@ -0,0 +1,469 @@
+/*
+ * 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");