igb: Add i2c interface to igb.

Some of our adapters have sensors on them accessible via i2c and a private
interface.  This patch implements the kernel interface for i2c to those sensors.
Subsequent patches will provide functions to export that data.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 269 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 342bbd661d3b..0173b6118424 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -57,6 +57,7 @@
 #ifdef CONFIG_IGB_DCA
 #include <linux/dca.h>
 #endif
+#include <linux/i2c.h>
 #include "igb.h"
 
 #define MAJ 4
@@ -567,6 +568,91 @@ exit:
         return;
 }
 
+/*  igb_get_i2c_data - Reads the I2C SDA data bit
+ *  @hw: pointer to hardware structure
+ *  @i2cctl: Current value of I2CCTL register
+ *
+ *  Returns the I2C data bit value
+ */
+static int igb_get_i2c_data(void *data)
+{
+        struct igb_adapter *adapter = (struct igb_adapter *)data;
+        struct e1000_hw *hw = &adapter->hw;
+        s32 i2cctl = rd32(E1000_I2CPARAMS);
+
+        return ((i2cctl & E1000_I2C_DATA_IN) != 0);
+}
+
+/* igb_set_i2c_data - Sets the I2C data bit
+ *  @data: pointer to hardware structure
+ *  @state: I2C data value (0 or 1) to set
+ *
+ *  Sets the I2C data bit
+ */
+static void igb_set_i2c_data(void *data, int state)
+{
+        struct igb_adapter *adapter = (struct igb_adapter *)data;
+        struct e1000_hw *hw = &adapter->hw;
+        s32 i2cctl = rd32(E1000_I2CPARAMS);
+
+        if (state)
+                i2cctl |= E1000_I2C_DATA_OUT;
+        else
+                i2cctl &= ~E1000_I2C_DATA_OUT;
+
+        i2cctl &= ~E1000_I2C_DATA_OE_N;
+        i2cctl |= E1000_I2C_CLK_OE_N;
+        wr32(E1000_I2CPARAMS, i2cctl);
+        wrfl();
+
+}
+
+/* igb_set_i2c_clk - Sets the I2C SCL clock
+ *  @data: pointer to hardware structure
+ *  @state: state to set clock
+ *
+ *  Sets the I2C clock line to state
+ */
+static void igb_set_i2c_clk(void *data, int state)
+{
+        struct igb_adapter *adapter = (struct igb_adapter *)data;
+        struct e1000_hw *hw = &adapter->hw;
+        s32 i2cctl = rd32(E1000_I2CPARAMS);
+
+        if (state) {
+                i2cctl |= E1000_I2C_CLK_OUT;
+                i2cctl &= ~E1000_I2C_CLK_OE_N;
+        } else {
+                i2cctl &= ~E1000_I2C_CLK_OUT;
+                i2cctl &= ~E1000_I2C_CLK_OE_N;
+        }
+        wr32(E1000_I2CPARAMS, i2cctl);
+        wrfl();
+}
+
+/* igb_get_i2c_clk - Gets the I2C SCL clock state
+ *  @data: pointer to hardware structure
+ *
+ *  Gets the I2C clock state
+ */
+static int igb_get_i2c_clk(void *data)
+{
+        struct igb_adapter *adapter = (struct igb_adapter *)data;
+        struct e1000_hw *hw = &adapter->hw;
+        s32 i2cctl = rd32(E1000_I2CPARAMS);
+
+        return ((i2cctl & E1000_I2C_CLK_IN) != 0);
+}
+
+static const struct i2c_algo_bit_data igb_i2c_algo = {
+        .setsda         = igb_set_i2c_data,
+        .setscl         = igb_set_i2c_clk,
+        .getsda         = igb_get_i2c_data,
+        .getscl         = igb_get_i2c_clk,
+        .udelay         = 5,
+        .timeout        = 20,
+};
+
 /**
  * igb_get_hw_dev - return device
  * used by hardware layer to print debugging information
@@ -1824,6 +1910,37 @@ void igb_set_fw_version(struct igb_adapter *adapter)
         return;
 }
 
+static const struct i2c_board_info i350_sensor_info = {
+        I2C_BOARD_INFO("i350bb", 0Xf8),
+};
+
+/*  igb_init_i2c - Init I2C interface
+ *  @adapter: pointer to adapter structure
+ *
+ */
+static s32 igb_init_i2c(struct igb_adapter *adapter)
+{
+        s32 status = E1000_SUCCESS;
+
+        /* I2C interface supported on i350 devices */
+        if (adapter->hw.mac.type != e1000_i350)
+                return E1000_SUCCESS;
+
+        /* Initialize the i2c bus which is controlled by the registers.
+         * This bus will use the i2c_algo_bit structue that implements
+         * the protocol through toggling of the 4 bits in the register.
+         */
+        adapter->i2c_adap.owner = THIS_MODULE;
+        adapter->i2c_algo = igb_i2c_algo;
+        adapter->i2c_algo.data = adapter;
+        adapter->i2c_adap.algo_data = &adapter->i2c_algo;
+        adapter->i2c_adap.dev.parent = &adapter->pdev->dev;
+        strlcpy(adapter->i2c_adap.name, "igb BB",
+                sizeof(adapter->i2c_adap.name));
+        status = i2c_bit_add_bus(&adapter->i2c_adap);
+        return status;
+}
+
 /**
  * igb_probe - Device Initialization Routine
  * @pdev: PCI device information struct
@@ -2116,6 +2233,13 @@ static int igb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
         /* reset the hardware with the new settings */
         igb_reset(adapter);
 
+        /* Init the I2C interface */
+        err = igb_init_i2c(adapter);
+        if (err) {
+                dev_err(&pdev->dev, "failed to init i2c interface\n");
+                goto err_eeprom;
+        }
+
         /* let the f/w know that the h/w is now under the control of the
          * driver. */
         igb_get_hw_control(adapter);
@@ -2177,6 +2301,7 @@ static int igb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 err_register:
         igb_release_hw_control(adapter);
+        memset(&adapter->i2c_adap, 0, sizeof(adapter->i2c_adap));
 err_eeprom:
         if (!igb_check_reset_block(hw))
                 igb_reset_phy(hw);
@@ -2290,6 +2415,18 @@ out:
 }
 
 #endif
+/*
+ *  igb_remove_i2c - Cleanup  I2C interface
+ *  @adapter: pointer to adapter structure
+ *
+ */
+static void igb_remove_i2c(struct igb_adapter *adapter)
+{
+
+        /* free the adapter bus structure */
+        i2c_del_adapter(&adapter->i2c_adap);
+}
+
 /**
  * igb_remove - Device Removal Routine
  * @pdev: PCI device information struct
@@ -2306,6 +2443,8 @@ static void igb_remove(struct pci_dev *pdev)
         struct e1000_hw *hw = &adapter->hw;
 
         pm_runtime_get_noresume(&pdev->dev);
+        igb_remove_i2c(adapter);
+
         igb_ptp_stop(adapter);
 
         /*
@@ -7425,4 +7564,134 @@ static void igb_init_dmac(struct igb_adapter *adapter, u32 pba)
         }
 }
 
+static DEFINE_SPINLOCK(i2c_clients_lock);
+
+/*  igb_get_i2c_client - returns matching client
+ *  in adapters's client list.
+ *  @adapter: adapter struct
+ *  @dev_addr: device address of i2c needed.
+ */
+struct i2c_client *
+igb_get_i2c_client(struct igb_adapter *adapter, u8 dev_addr)
+{
+        ulong flags;
+        struct igb_i2c_client_list *client_list;
+        struct i2c_client *client = NULL;
+        struct i2c_board_info client_info = {
+                I2C_BOARD_INFO("igb", 0x00),
+        };
+
+        spin_lock_irqsave(&i2c_clients_lock, flags);
+        client_list = adapter->i2c_clients;
+
+        /* See if we already have an i2c_client */
+        while (client_list) {
+                if (client_list->client->addr == (dev_addr >> 1)) {
+                        client = client_list->client;
+                        goto exit;
+                } else {
+                        client_list = client_list->next;
+                }
+        }
+
+        /* no client_list found, create a new one */
+        client_list = kzalloc(sizeof(*client_list), GFP_KERNEL);
+        if (client_list == NULL)
+                goto exit;
+
+        /* dev_addr passed to us is left-shifted by 1 bit
+         * i2c_new_device call expects it to be flush to the right.
+         */
+        client_info.addr = dev_addr >> 1;
+        client_info.platform_data = adapter;
+        client_list->client = i2c_new_device(&adapter->i2c_adap, &client_info);
+        if (client_list->client == NULL) {
+                dev_info(&adapter->pdev->dev, "Failed to create new i2c device..\n");
+                goto err_no_client;
+        }
+
+        /* insert new client at head of list */
+        client_list->next = adapter->i2c_clients;
+        adapter->i2c_clients = client_list;
+
+        spin_unlock_irqrestore(&i2c_clients_lock, flags);
+
+        client = client_list->client;
+        goto exit;
+
+err_no_client:
+        kfree(client_list);
+exit:
+        spin_unlock_irqrestore(&i2c_clients_lock, flags);
+        return client;
+}
+
+/*  igb_read_i2c_byte - Reads 8 bit word over I2C
+ *  @hw: pointer to hardware structure
+ *  @byte_offset: byte offset to read
+ *  @dev_addr: device address
+ *  @data: value read
+ *
+ *  Performs byte read operation over I2C interface at
+ *  a specified device address.
+ */
+s32 igb_read_i2c_byte(struct e1000_hw *hw, u8 byte_offset,
+                                u8 dev_addr, u8 *data)
+{
+        struct igb_adapter *adapter = container_of(hw, struct igb_adapter, hw);
+        struct i2c_client *this_client = igb_get_i2c_client(adapter, dev_addr);
+        s32 status;
+        u16 swfw_mask = 0;
+
+        if (!this_client)
+                return E1000_ERR_I2C;
+
+        swfw_mask = E1000_SWFW_PHY0_SM;
+
+        if (hw->mac.ops.acquire_swfw_sync(hw, swfw_mask)
+            != E1000_SUCCESS)
+                return E1000_ERR_SWFW_SYNC;
+
+        status = i2c_smbus_read_byte_data(this_client, byte_offset);
+        hw->mac.ops.release_swfw_sync(hw, swfw_mask);
+
+        if (status < 0)
+                return E1000_ERR_I2C;
+        else {
+                *data = status;
+                return E1000_SUCCESS;
+        }
+}
+
+/*  igb_write_i2c_byte - Writes 8 bit word over I2C
+ *  @hw: pointer to hardware structure
+ *  @byte_offset: byte offset to write
+ *  @dev_addr: device address
+ *  @data: value to write
+ *
+ *  Performs byte write operation over I2C interface at
+ *  a specified device address.
+ */
+s32 igb_write_i2c_byte(struct e1000_hw *hw, u8 byte_offset,
+                                 u8 dev_addr, u8 data)
+{
+        struct igb_adapter *adapter = container_of(hw, struct igb_adapter, hw);
+        struct i2c_client *this_client = igb_get_i2c_client(adapter, dev_addr);
+        s32 status;
+        u16 swfw_mask = E1000_SWFW_PHY0_SM;
+
+        if (!this_client)
+                return E1000_ERR_I2C;
+
+        if (hw->mac.ops.acquire_swfw_sync(hw, swfw_mask) != E1000_SUCCESS)
+                return E1000_ERR_SWFW_SYNC;
+        status = i2c_smbus_write_byte_data(this_client, byte_offset, data);
+        hw->mac.ops.release_swfw_sync(hw, swfw_mask);
+
+        if (status)
+                return E1000_ERR_I2C;
+        else
+                return E1000_SUCCESS;
+
+}
 /* igb_main.c */