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path: root/drivers/net/sfc/i2c-direct.c
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Diffstat (limited to 'drivers/net/sfc/i2c-direct.c')
-rw-r--r--drivers/net/sfc/i2c-direct.c381
1 files changed, 0 insertions, 381 deletions
diff --git a/drivers/net/sfc/i2c-direct.c b/drivers/net/sfc/i2c-direct.c
deleted file mode 100644
index b6c62d0ed9c2..000000000000
--- a/drivers/net/sfc/i2c-direct.c
+++ /dev/null
@@ -1,381 +0,0 @@
-/****************************************************************************
- * Driver for Solarflare Solarstorm network controllers and boards
- * Copyright 2005 Fen Systems Ltd.
- * Copyright 2006-2008 Solarflare Communications Inc.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation, incorporated herein by reference.
- */
-
-#include <linux/delay.h>
-#include "net_driver.h"
-#include "i2c-direct.h"
-
-/*
- * I2C data (SDA) and clock (SCL) line read/writes with appropriate
- * delays.
- */
-
-static inline void setsda(struct efx_i2c_interface *i2c, int state)
-{
- udelay(i2c->op->udelay);
- i2c->sda = state;
- i2c->op->setsda(i2c);
- udelay(i2c->op->udelay);
-}
-
-static inline void setscl(struct efx_i2c_interface *i2c, int state)
-{
- udelay(i2c->op->udelay);
- i2c->scl = state;
- i2c->op->setscl(i2c);
- udelay(i2c->op->udelay);
-}
-
-static inline int getsda(struct efx_i2c_interface *i2c)
-{
- int sda;
-
- udelay(i2c->op->udelay);
- sda = i2c->op->getsda(i2c);
- udelay(i2c->op->udelay);
- return sda;
-}
-
-static inline int getscl(struct efx_i2c_interface *i2c)
-{
- int scl;
-
- udelay(i2c->op->udelay);
- scl = i2c->op->getscl(i2c);
- udelay(i2c->op->udelay);
- return scl;
-}
-
-/*
- * I2C low-level protocol operations
- *
- */
-
-static inline void i2c_release(struct efx_i2c_interface *i2c)
-{
- EFX_WARN_ON_PARANOID(!i2c->scl);
- EFX_WARN_ON_PARANOID(!i2c->sda);
- /* Devices may time out if operations do not end */
- setscl(i2c, 1);
- setsda(i2c, 1);
- EFX_BUG_ON_PARANOID(getsda(i2c) != 1);
- EFX_BUG_ON_PARANOID(getscl(i2c) != 1);
-}
-
-static inline void i2c_start(struct efx_i2c_interface *i2c)
-{
- /* We may be restarting immediately after a {send,recv}_bit,
- * so SCL will not necessarily already be high.
- */
- EFX_WARN_ON_PARANOID(!i2c->sda);
- setscl(i2c, 1);
- setsda(i2c, 0);
- setscl(i2c, 0);
- setsda(i2c, 1);
-}
-
-static inline void i2c_send_bit(struct efx_i2c_interface *i2c, int bit)
-{
- EFX_WARN_ON_PARANOID(i2c->scl != 0);
- setsda(i2c, bit);
- setscl(i2c, 1);
- setscl(i2c, 0);
- setsda(i2c, 1);
-}
-
-static inline int i2c_recv_bit(struct efx_i2c_interface *i2c)
-{
- int bit;
-
- EFX_WARN_ON_PARANOID(i2c->scl != 0);
- EFX_WARN_ON_PARANOID(!i2c->sda);
- setscl(i2c, 1);
- bit = getsda(i2c);
- setscl(i2c, 0);
- return bit;
-}
-
-static inline void i2c_stop(struct efx_i2c_interface *i2c)
-{
- EFX_WARN_ON_PARANOID(i2c->scl != 0);
- setsda(i2c, 0);
- setscl(i2c, 1);
- setsda(i2c, 1);
-}
-
-/*
- * I2C mid-level protocol operations
- *
- */
-
-/* Sends a byte via the I2C bus and checks for an acknowledgement from
- * the slave device.
- */
-static int i2c_send_byte(struct efx_i2c_interface *i2c, u8 byte)
-{
- int i;
-
- /* Send byte */
- for (i = 0; i < 8; i++) {
- i2c_send_bit(i2c, !!(byte & 0x80));
- byte <<= 1;
- }
-
- /* Check for acknowledgement from slave */
- return (i2c_recv_bit(i2c) == 0 ? 0 : -EIO);
-}
-
-/* Receives a byte via the I2C bus and sends ACK/NACK to the slave device. */
-static u8 i2c_recv_byte(struct efx_i2c_interface *i2c, int ack)
-{
- u8 value = 0;
- int i;
-
- /* Receive byte */
- for (i = 0; i < 8; i++)
- value = (value << 1) | i2c_recv_bit(i2c);
-
- /* Send ACK/NACK */
- i2c_send_bit(i2c, (ack ? 0 : 1));
-
- return value;
-}
-
-/* Calculate command byte for a read operation */
-static inline u8 i2c_read_cmd(u8 device_id)
-{
- return ((device_id << 1) | 1);
-}
-
-/* Calculate command byte for a write operation */
-static inline u8 i2c_write_cmd(u8 device_id)
-{
- return ((device_id << 1) | 0);
-}
-
-int efx_i2c_check_presence(struct efx_i2c_interface *i2c, u8 device_id)
-{
- int rc;
-
- /* If someone is driving the bus low we just give up. */
- if (getsda(i2c) == 0 || getscl(i2c) == 0) {
- EFX_ERR(i2c->efx, "%s someone is holding the I2C bus low."
- " Giving up.\n", __func__);
- return -EFAULT;
- }
-
- /* Pretend to initiate a device write */
- i2c_start(i2c);
- rc = i2c_send_byte(i2c, i2c_write_cmd(device_id));
- if (rc)
- goto out;
-
- out:
- i2c_stop(i2c);
- i2c_release(i2c);
-
- return rc;
-}
-
-/* This performs a fast read of one or more consecutive bytes from an
- * I2C device. Not all devices support consecutive reads of more than
- * one byte; for these devices use efx_i2c_read() instead.
- */
-int efx_i2c_fast_read(struct efx_i2c_interface *i2c,
- u8 device_id, u8 offset, u8 *data, unsigned int len)
-{
- int i;
- int rc;
-
- EFX_WARN_ON_PARANOID(getsda(i2c) != 1);
- EFX_WARN_ON_PARANOID(getscl(i2c) != 1);
- EFX_WARN_ON_PARANOID(data == NULL);
- EFX_WARN_ON_PARANOID(len < 1);
-
- /* Select device and starting offset */
- i2c_start(i2c);
- rc = i2c_send_byte(i2c, i2c_write_cmd(device_id));
- if (rc)
- goto out;
- rc = i2c_send_byte(i2c, offset);
- if (rc)
- goto out;
-
- /* Read data from device */
- i2c_start(i2c);
- rc = i2c_send_byte(i2c, i2c_read_cmd(device_id));
- if (rc)
- goto out;
- for (i = 0; i < (len - 1); i++)
- /* Read and acknowledge all but the last byte */
- data[i] = i2c_recv_byte(i2c, 1);
- /* Read last byte with no acknowledgement */
- data[i] = i2c_recv_byte(i2c, 0);
-
- out:
- i2c_stop(i2c);
- i2c_release(i2c);
-
- return rc;
-}
-
-/* This performs a fast write of one or more consecutive bytes to an
- * I2C device. Not all devices support consecutive writes of more
- * than one byte; for these devices use efx_i2c_write() instead.
- */
-int efx_i2c_fast_write(struct efx_i2c_interface *i2c,
- u8 device_id, u8 offset,
- const u8 *data, unsigned int len)
-{
- int i;
- int rc;
-
- EFX_WARN_ON_PARANOID(getsda(i2c) != 1);
- EFX_WARN_ON_PARANOID(getscl(i2c) != 1);
- EFX_WARN_ON_PARANOID(len < 1);
-
- /* Select device and starting offset */
- i2c_start(i2c);
- rc = i2c_send_byte(i2c, i2c_write_cmd(device_id));
- if (rc)
- goto out;
- rc = i2c_send_byte(i2c, offset);
- if (rc)
- goto out;
-
- /* Write data to device */
- for (i = 0; i < len; i++) {
- rc = i2c_send_byte(i2c, data[i]);
- if (rc)
- goto out;
- }
-
- out:
- i2c_stop(i2c);
- i2c_release(i2c);
-
- return rc;
-}
-
-/* I2C byte-by-byte read */
-int efx_i2c_read(struct efx_i2c_interface *i2c,
- u8 device_id, u8 offset, u8 *data, unsigned int len)
-{
- int rc;
-
- /* i2c_fast_read with length 1 is a single byte read */
- for (; len > 0; offset++, data++, len--) {
- rc = efx_i2c_fast_read(i2c, device_id, offset, data, 1);
- if (rc)
- return rc;
- }
-
- return 0;
-}
-
-/* I2C byte-by-byte write */
-int efx_i2c_write(struct efx_i2c_interface *i2c,
- u8 device_id, u8 offset, const u8 *data, unsigned int len)
-{
- int rc;
-
- /* i2c_fast_write with length 1 is a single byte write */
- for (; len > 0; offset++, data++, len--) {
- rc = efx_i2c_fast_write(i2c, device_id, offset, data, 1);
- if (rc)
- return rc;
- mdelay(i2c->op->mdelay);
- }
-
- return 0;
-}
-
-
-/* This is just a slightly neater wrapper round efx_i2c_fast_write
- * in the case where the target doesn't take an offset
- */
-int efx_i2c_send_bytes(struct efx_i2c_interface *i2c,
- u8 device_id, const u8 *data, unsigned int len)
-{
- return efx_i2c_fast_write(i2c, device_id, data[0], data + 1, len - 1);
-}
-
-/* I2C receiving of bytes - does not send an offset byte */
-int efx_i2c_recv_bytes(struct efx_i2c_interface *i2c, u8 device_id,
- u8 *bytes, unsigned int len)
-{
- int i;
- int rc;
-
- EFX_WARN_ON_PARANOID(getsda(i2c) != 1);
- EFX_WARN_ON_PARANOID(getscl(i2c) != 1);
- EFX_WARN_ON_PARANOID(len < 1);
-
- /* Select device */
- i2c_start(i2c);
-
- /* Read data from device */
- rc = i2c_send_byte(i2c, i2c_read_cmd(device_id));
- if (rc)
- goto out;
-
- for (i = 0; i < (len - 1); i++)
- /* Read and acknowledge all but the last byte */
- bytes[i] = i2c_recv_byte(i2c, 1);
- /* Read last byte with no acknowledgement */
- bytes[i] = i2c_recv_byte(i2c, 0);
-
- out:
- i2c_stop(i2c);
- i2c_release(i2c);
-
- return rc;
-}
-
-/* SMBus and some I2C devices will time out if the I2C clock is
- * held low for too long. This is most likely to happen in virtualised
- * systems (when the entire domain is descheduled) but could in
- * principle happen due to preemption on any busy system (and given the
- * potential length of an I2C operation turning preemption off is not
- * a sensible option). The following functions deal with the failure by
- * retrying up to a fixed number of times.
- */
-
-#define I2C_MAX_RETRIES (10)
-
-/* The timeout problem will result in -EIO. If the wrapped function
- * returns any other error, pass this up and do not retry. */
-#define RETRY_WRAPPER(_f) \
- int retries = I2C_MAX_RETRIES; \
- int rc; \
- while (retries) { \
- rc = _f; \
- if (rc != -EIO) \
- return rc; \
- retries--; \
- } \
- return rc; \
-
-int efx_i2c_check_presence_retry(struct efx_i2c_interface *i2c, u8 device_id)
-{
- RETRY_WRAPPER(efx_i2c_check_presence(i2c, device_id))
-}
-
-int efx_i2c_read_retry(struct efx_i2c_interface *i2c,
- u8 device_id, u8 offset, u8 *data, unsigned int len)
-{
- RETRY_WRAPPER(efx_i2c_read(i2c, device_id, offset, data, len))
-}
-
-int efx_i2c_write_retry(struct efx_i2c_interface *i2c,
- u8 device_id, u8 offset, const u8 *data, unsigned int len)
-{
- RETRY_WRAPPER(efx_i2c_write(i2c, device_id, offset, data, len))
-}
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