1 files changed, 188 insertions, 0 deletions

diff --git a/arch/mips/pmc-sierra/yosemite/i2c-yosemite.c b/arch/mips/pmc-sierra/yosemite/i2c-yosemite.c
new file mode 100644
index 000000000000..416da22b3bf4
--- /dev/null
+++ b/arch/mips/pmc-sierra/yosemite/i2c-yosemite.c
@@ -0,0 +1,188 @@
+/*
+ *  Copyright (C) 2003 PMC-Sierra Inc.
+ *  Author: Manish Lachwani (lachwani@pmc-sierra.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  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
+ *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+ *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
+ *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
+ *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * Detailed Description:
+ *
+ * This block implements the I2C interface to the slave devices like the
+ * Atmel 24C32 EEPROM and the MAX 1619 Sensors device. The I2C Master interface
+ * can be controlled by the SCMB block. And the SCMB block kicks in only when
+ * using the Ethernet Mode of operation and __not__ the SysAD mode
+ *
+ * The SCMB controls the two modes: MDIO and the I2C. The MDIO mode is used to
+ * communicate with the Quad-PHY from Marvel. The I2C is used to communicate
+ * with the I2C slave devices.  It seems that the driver does not explicitly
+ * deal with the control of SDA and SCL serial lines. So, the driver will set
+ * the slave address, drive the command and then the data.  The SCMB will then
+ * control the two serial lines as required.
+ *
+ * It seems the documents are very unclear abt this. Hence, I took some time
+ * out to write the desciption to have an idea of how the I2C can actually
+ * work. Currently, this Linux driver wont be integrated into the generic Linux
+ * I2C framework. And finally, the I2C interface is also known as the 2BI
+ * interface. 2BI means 2-bit interface referring to SDA and SCL serial lines
+ * respectively.
+ *
+ * - Manish Lachwani (12/09/2003)
+ */
+
+#include "i2c-yosemite.h"
+
+/*
+ * Poll the I2C interface for the BUSY bit.
+ */
+static int titan_i2c_poll(void)
+{
+        int i = 0;
+        unsigned long val = 0;
+
+        for (i = 0; i < TITAN_I2C_MAX_POLL; i++) {
+                val = TITAN_I2C_READ(TITAN_I2C_COMMAND);
+
+                if (!(val & 0x8000))
+                        return 0;
+        }
+
+        return TITAN_I2C_ERR_TIMEOUT;
+}
+
+/*
+ * Execute the I2C command
+ */
+int titan_i2c_xfer(unsigned int slave_addr, titan_i2c_command * cmd,
+                   int size, unsigned int *addr)
+{
+        int loop = 0, bytes, i;
+        unsigned int *write_data, data, *read_data;
+        unsigned long reg_val, val;
+
+        write_data = cmd->data;
+        read_data = addr;
+
+        TITAN_I2C_WRITE(TITAN_I2C_SLAVE_ADDRESS, slave_addr);
+
+        if (cmd->type == TITAN_I2C_CMD_WRITE)
+                loop = cmd->write_size;
+        else
+                loop = size;
+
+        while (loop > 0) {
+                if ((cmd->type == TITAN_I2C_CMD_WRITE) ||
+                    (cmd->type == TITAN_I2C_CMD_READ_WRITE)) {
+
+                        reg_val = TITAN_I2C_DATA;
+                        for (i = 0; i < TITAN_I2C_MAX_WORDS_PER_RW;
+                             ++i, write_data += 2, reg_val += 4) {
+                                if (bytes < cmd->write_size) {
+                                        data = write_data[0];
+                                        ++data;
+                                }
+
+                                if (bytes < cmd->write_size) {
+                                        data = write_data[1];
+                                        ++data;
+                                }
+
+                                TITAN_I2C_WRITE(reg_val, data);
+                        }
+                }
+
+                TITAN_I2C_WRITE(TITAN_I2C_COMMAND,
+                                (unsigned int) (cmd->type << 13));
+                if (titan_i2c_poll() != TITAN_I2C_ERR_OK)
+                        return TITAN_I2C_ERR_TIMEOUT;
+
+                if ((cmd->type == TITAN_I2C_CMD_READ) ||
+                    (cmd->type == TITAN_I2C_CMD_READ_WRITE)) {
+
+                        reg_val = TITAN_I2C_DATA;
+                        for (i = 0; i < TITAN_I2C_MAX_WORDS_PER_RW;
+                             ++i, read_data += 2, reg_val += 4) {
+                                data = TITAN_I2C_READ(reg_val);
+
+                                if (bytes < size) {
+                                        read_data[0] = data & 0xff;
+                                        ++bytes;
+                                }
+
+                                if (bytes < size) {
+                                        read_data[1] =
+                                            ((data >> 8) & 0xff);
+                                        ++bytes;
+                                }
+                        }
+                }
+
+                loop -= (TITAN_I2C_MAX_WORDS_PER_RW * 2);
+        }
+
+        /*
+         * Read the Interrupt status and then return the appropriate error code
+         */
+
+        val = TITAN_I2C_READ(TITAN_I2C_INTERRUPTS);
+        if (val & 0x0020)
+                return TITAN_I2C_ERR_ARB_LOST;
+
+        if (val & 0x0040)
+                return TITAN_I2C_ERR_NO_RESP;
+
+        if (val & 0x0080)
+                return TITAN_I2C_ERR_DATA_COLLISION;
+
+        return TITAN_I2C_ERR_OK;
+}
+
+/*
+ * Init the I2C subsystem of the PMC-Sierra Yosemite board
+ */
+int titan_i2c_init(titan_i2c_config * config)
+{
+        unsigned int val;
+
+        /*
+         * Reset the SCMB and program into the I2C mode
+         */
+        TITAN_I2C_WRITE(TITAN_I2C_SCMB_CONTROL, 0xA000);
+        TITAN_I2C_WRITE(TITAN_I2C_SCMB_CONTROL, 0x2000);
+
+        /*
+         * Configure the filtera and clka values
+         */
+        val = TITAN_I2C_READ(TITAN_I2C_SCMB_CLOCK_A);
+        val |= ((val & ~(0xF000)) | ((config->filtera << 12) & 0xF000));
+        val |= ((val & ~(0x03FF)) | (config->clka & 0x03FF));
+        TITAN_I2C_WRITE(TITAN_I2C_SCMB_CLOCK_A, val);
+
+        /*
+         * Configure the filterb and clkb values
+         */
+        val = TITAN_I2C_READ(TITAN_I2C_SCMB_CLOCK_B);
+        val |= ((val & ~(0xF000)) | ((config->filterb << 12) & 0xF000));
+        val |= ((val & ~(0x03FF)) | (config->clkb & 0x03FF));
+        TITAN_I2C_WRITE(TITAN_I2C_SCMB_CLOCK_B, val);
+
+        return TITAN_I2C_ERR_OK;
+}