1 files changed, 186 insertions, 0 deletions

diff --git a/firmware/target/arm/imx233/i2c-imx233.c b/firmware/target/arm/imx233/i2c-imx233.c
new file mode 100644
index 0000000000..9d29605bce
--- /dev/null
+++ b/firmware/target/arm/imx233/i2c-imx233.c
@@ -0,0 +1,186 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2011 by amaury Pouly
+ *
+ * Based on Rockbox iriver bootloader by Linus Nielsen Feltzing
+ * and the ipodlinux bootloader by Daniel Palffy and Bernard Leach
+ * 
+ * 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 distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "config.h"
+#include "system.h"
+#include "kernel.h"
+#include "dma-imx233.h"
+#include "i2c-imx233.h"
+#include "pinctrl-imx233.h"
+
+/* Used for DMA */
+struct i2c_dma_command_t
+{
+    struct apb_dma_command_t dma;
+    /* PIO words */
+    uint32_t ctrl0;
+};
+
+#define I2C_NR_STAGES   4
+/* Current transfer */
+static int i2c_nr_stages;
+static struct i2c_dma_command_t i2c_stage[I2C_NR_STAGES];
+static struct mutex i2c_mutex;
+static struct semaphore i2c_sema;
+
+void INT_I2C_DMA(void)
+{
+    /* reset dma channel on error */
+    if(imx233_dma_is_channel_error_irq(APB_I2C))
+        imx233_dma_reset_channel(APB_I2C);
+    /* clear irq flags */
+    imx233_dma_clear_channel_interrupt(APB_I2C);
+    semaphore_release(&i2c_sema);
+}
+
+void imx233_i2c_init(void)
+{
+    __REG_SET(HW_I2C_CTRL0) = __BLOCK_SFTRST | __BLOCK_CLKGATE;
+    /* setup pins (must be done when shutdown) */
+    imx233_set_pin_function(0, 30, PINCTRL_FUNCTION_MAIN);
+    imx233_set_pin_function(0, 31, PINCTRL_FUNCTION_MAIN);
+    /* clear softreset */
+    __REG_CLR(HW_I2C_CTRL0) = __BLOCK_SFTRST | __BLOCK_CLKGATE;
+    /* Errata:
+     * When RETAIN_CLOCK is set, the ninth clock pulse (ACK) is not generated. However, the SDA
+     * line is read at the proper timing interval. If RETAIN_CLOCK is cleared, the ninth clock pulse is
+     * generated.
+     * HW_I2C_CTRL1[ACK_MODE] has default value of 0. It should be set to 1 to enable the fix for
+     * this issue.
+     */
+    __REG_SET(HW_I2C_CTRL1) = HW_I2C_CTRL1__ACK_MODE;
+    __REG_SET(HW_I2C_CTRL0) = __BLOCK_CLKGATE;
+    /* Fast-mode @ 400K */
+    HW_I2C_TIMING0 = 0x000F0007; /* tHIGH=0.6us, read at 0.3us */
+    HW_I2C_TIMING1 = 0x001F000F; /* tLOW=1.3us, write at 0.6us */
+    HW_I2C_TIMING2 = 0x0015000D;
+    
+    mutex_init(&i2c_mutex);
+    semaphore_init(&i2c_sema, 1, 0);
+}
+
+void imx233_i2c_begin(void)
+{
+    mutex_lock(&i2c_mutex);
+    /* wakeup */
+    __REG_CLR(HW_I2C_CTRL0) = __BLOCK_CLKGATE;
+    i2c_nr_stages = 0;
+}
+
+enum imx233_i2c_error_t imx233_i2c_add(bool start, bool transmit, void *buffer, unsigned size, bool stop)
+{
+    if(i2c_nr_stages == I2C_NR_STAGES)
+        return I2C_ERROR;
+    if(i2c_nr_stages > 0)
+    {
+        i2c_stage[i2c_nr_stages - 1].dma.next = &i2c_stage[i2c_nr_stages].dma;
+        i2c_stage[i2c_nr_stages - 1].dma.cmd |= HW_APB_CHx_CMD__CHAIN;
+        if(!start)
+            i2c_stage[i2c_nr_stages - 1].ctrl0 |= HW_I2C_CTRL0__RETAIN_CLOCK;
+    }
+    i2c_stage[i2c_nr_stages].dma.buffer = buffer;
+    i2c_stage[i2c_nr_stages].dma.next = NULL;
+    i2c_stage[i2c_nr_stages].dma.cmd =
+        (transmit ? HW_APB_CHx_CMD__COMMAND__READ : HW_APB_CHx_CMD__COMMAND__WRITE) |
+        HW_APB_CHx_CMD__WAIT4ENDCMD |
+        1 << HW_APB_CHx_CMD__CMDWORDS_BP |
+        size << HW_APB_CHx_CMD__XFER_COUNT_BP;
+    /* assume that any read is final (send nak on last) */
+    i2c_stage[i2c_nr_stages].ctrl0 = size |
+        (transmit ? HW_I2C_CTRL0__TRANSMIT : HW_I2C_CTRL0__SEND_NAK_ON_LAST) |
+        (start ? HW_I2C_CTRL0__PRE_SEND_START : 0) |
+        (stop ? HW_I2C_CTRL0__POST_SEND_STOP : 0) |
+        HW_I2C_CTRL0__MASTER_MODE;
+    i2c_nr_stages++;
+    return I2C_SUCCESS;
+}
+
+enum imx233_i2c_error_t imx233_i2c_end(unsigned timeout)
+{
+    if(i2c_nr_stages == 0)
+        return I2C_ERROR;
+    i2c_stage[i2c_nr_stages - 1].dma.cmd |= HW_APB_CHx_CMD__SEMAPHORE | HW_APB_CHx_CMD__IRQONCMPLT;
+
+    __REG_CLR(HW_I2C_CTRL1) = HW_I2C_CTRL1__ALL_IRQ;
+    imx233_enable_interrupt(INT_SRC_I2C_DMA, true);
+    imx233_dma_enable_channel_interrupt(APB_I2C, true);
+    imx233_dma_reset_channel(APB_I2C);
+    imx233_dma_start_command(APB_I2C, &i2c_stage[0].dma);
+
+    enum imx233_i2c_error_t ret ;
+    if(semaphore_wait(&i2c_sema, timeout) == OBJ_WAIT_TIMEDOUT)
+    {
+        imx233_dma_reset_channel(APB_I2C);
+        ret = I2C_TIMEOUT;
+    }
+    else if(HW_I2C_CTRL1 & HW_I2C_CTRL1__MASTER_LOSS_IRQ)
+        ret = I2C_MASTER_LOSS;
+    else if(HW_I2C_CTRL1 & HW_I2C_CTRL1__NO_SLAVE_ACK_IRQ)
+        ret= I2C_NO_SLAVE_ACK;
+    else if(HW_I2C_CTRL1 & HW_I2C_CTRL1__EARLY_TERM_IRQ)
+        ret = I2C_SLAVE_NAK;
+    else
+        ret = I2C_SUCCESS;
+    /* sleep */
+    __REG_SET(HW_I2C_CTRL0) = __BLOCK_CLKGATE;
+    mutex_unlock(&i2c_mutex);
+    return ret;
+}
+
+int i2c_write(int device, const unsigned char* buf, int count)
+{
+    uint8_t addr = device;
+    imx233_i2c_begin();
+    imx233_i2c_add(true, true, &addr, 1, false); /* start + addr */
+    imx233_i2c_add(false, true, (void *)buf, count, true); /* data + stop */
+    return imx233_i2c_end(TIMEOUT_BLOCK);
+}
+
+int i2c_read(int device, unsigned char* buf, int count)
+{
+    uint8_t addr = device | 1;
+    imx233_i2c_begin();
+    imx233_i2c_add(true, true, &addr, 1, false); /* start + addr */
+    imx233_i2c_add(false, false, buf, count, true); /* data + stop */
+    return imx233_i2c_end(TIMEOUT_BLOCK);
+}
+
+int i2c_readmem(int device, int address, unsigned char* buf, int count)
+{
+    uint8_t start[2] = {device, address};
+    uint8_t addr_rd = device | 1;
+    imx233_i2c_begin();
+    imx233_i2c_add(true, true, start, 2, false); /* start + addr + addr */
+    imx233_i2c_add(true, true, &addr_rd, 1, false); /* start + addr */
+    imx233_i2c_add(false, false, buf, count, true); /* data + stop */
+    return imx233_i2c_end(TIMEOUT_BLOCK);
+}
+
+int i2c_writemem(int device, int address, const unsigned char* buf, int count)
+{
+    uint8_t start[2] = {device, address};
+    imx233_i2c_begin();
+    imx233_i2c_add(true, true, start, 2, false); /* start + addr + addr */
+    imx233_i2c_add(false, true, (void *)buf, count, true); /* data + stop */
+    return imx233_i2c_end(TIMEOUT_BLOCK);
+}