sfc: Use kernel I2C system and i2c-algo-bit driver

Remove our own implementation of I2C bit-banging.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 52 insertions, 20 deletions

diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c
index d3f749c72d41..8acd53de5e7c 100644
--- a/drivers/net/sfc/falcon.c
+++ b/drivers/net/sfc/falcon.c
@@ -13,6 +13,8 @@
 #include <linux/pci.h>
 #include <linux/module.h>
 #include <linux/seq_file.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
 #include "net_driver.h"
 #include "bitfield.h"
 #include "efx.h"
@@ -36,10 +38,12 @@
  * struct falcon_nic_data - Falcon NIC state
  * @next_buffer_table: First available buffer table id
  * @pci_dev2: The secondary PCI device if present
+ * @i2c_data: Operations and state for I2C bit-bashing algorithm
  */
 struct falcon_nic_data {
         unsigned next_buffer_table;
         struct pci_dev *pci_dev2;
+        struct i2c_algo_bit_data i2c_data;
 };
 
 /**************************************************************************
@@ -175,39 +179,57 @@ static inline int falcon_event_present(efx_qword_t *event)
  *
  **************************************************************************
  */
-static void falcon_setsdascl(struct efx_i2c_interface *i2c)
+static void falcon_setsda(void *data, int state)
 {
+        struct efx_nic *efx = (struct efx_nic *)data;
         efx_oword_t reg;
 
-        falcon_read(i2c->efx, &reg, GPIO_CTL_REG_KER);
-        EFX_SET_OWORD_FIELD(reg, GPIO0_OEN, (i2c->scl ? 0 : 1));
-        EFX_SET_OWORD_FIELD(reg, GPIO3_OEN, (i2c->sda ? 0 : 1));
-        falcon_write(i2c->efx, &reg, GPIO_CTL_REG_KER);
+        falcon_read(efx, &reg, GPIO_CTL_REG_KER);
+        EFX_SET_OWORD_FIELD(reg, GPIO3_OEN, !state);
+        falcon_write(efx, &reg, GPIO_CTL_REG_KER);
 }
 
-static int falcon_getsda(struct efx_i2c_interface *i2c)
+static void falcon_setscl(void *data, int state)
 {
+        struct efx_nic *efx = (struct efx_nic *)data;
         efx_oword_t reg;
 
-        falcon_read(i2c->efx, &reg, GPIO_CTL_REG_KER);
+        falcon_read(efx, &reg, GPIO_CTL_REG_KER);
+        EFX_SET_OWORD_FIELD(reg, GPIO0_OEN, !state);
+        falcon_write(efx, &reg, GPIO_CTL_REG_KER);
+}
+
+static int falcon_getsda(void *data)
+{
+        struct efx_nic *efx = (struct efx_nic *)data;
+        efx_oword_t reg;
+
+        falcon_read(efx, &reg, GPIO_CTL_REG_KER);
         return EFX_OWORD_FIELD(reg, GPIO3_IN);
 }
 
-static int falcon_getscl(struct efx_i2c_interface *i2c)
+static int falcon_getscl(void *data)
 {
+        struct efx_nic *efx = (struct efx_nic *)data;
         efx_oword_t reg;
 
-        falcon_read(i2c->efx, &reg, GPIO_CTL_REG_KER);
-        return EFX_DWORD_FIELD(reg, GPIO0_IN);
+        falcon_read(efx, &reg, GPIO_CTL_REG_KER);
+        return EFX_OWORD_FIELD(reg, GPIO0_IN);
 }
 
-static struct efx_i2c_bit_operations falcon_i2c_bit_operations = {
-        .setsda         = falcon_setsdascl,
-        .setscl         = falcon_setsdascl,
+static struct i2c_algo_bit_data falcon_i2c_bit_operations = {
+        .setsda         = falcon_setsda,
+        .setscl         = falcon_setscl,
         .getsda         = falcon_getsda,
         .getscl         = falcon_getscl,
         .udelay         = 100,
-        .mdelay         = 10,
+        /*
+         * This is the number of system clock ticks after which
+         * i2c-algo-bit gives up waiting for SCL to become high.
+         * It must be at least 2 since the first tick can happen
+         * immediately after it starts waiting.
+         */
+        .timeout        = 2,
 };
 
 /**************************************************************************
@@ -2403,12 +2425,6 @@ int falcon_probe_nic(struct efx_nic *efx)
         struct falcon_nic_data *nic_data;
         int rc;
 
-        /* Initialise I2C interface state */
-        efx->i2c.efx = efx;
-        efx->i2c.op = &falcon_i2c_bit_operations;
-        efx->i2c.sda = 1;
-        efx->i2c.scl = 1;
-
         /* Allocate storage for hardware specific data */
         nic_data = kzalloc(sizeof(*nic_data), GFP_KERNEL);
         efx->nic_data = nic_data;
@@ -2459,6 +2475,18 @@ int falcon_probe_nic(struct efx_nic *efx)
         if (rc)
                 goto fail5;
 
+        /* Initialise I2C adapter */
+        efx->i2c_adap.owner = THIS_MODULE;
+        efx->i2c_adap.class = I2C_CLASS_HWMON;
+        nic_data->i2c_data = falcon_i2c_bit_operations;
+        nic_data->i2c_data.data = efx;
+        efx->i2c_adap.algo_data = &nic_data->i2c_data;
+        efx->i2c_adap.dev.parent = &efx->pci_dev->dev;
+        strcpy(efx->i2c_adap.name, "SFC4000 GPIO");
+        rc = i2c_bit_add_bus(&efx->i2c_adap);
+        if (rc)
+                goto fail5;
+
         return 0;
 
  fail5:
@@ -2633,6 +2661,10 @@ int falcon_init_nic(struct efx_nic *efx)
 void falcon_remove_nic(struct efx_nic *efx)
 {
         struct falcon_nic_data *nic_data = efx->nic_data;
+        int rc;
+
+        rc = i2c_del_adapter(&efx->i2c_adap);
+        BUG_ON(rc);
 
         falcon_free_buffer(efx, &efx->irq_status);