arm, i2c: added support for the TWSI I2C Interface
authorHeiko Schocher <hs@denx.de>
Mon, 20 Jul 2009 07:59:37 +0000 (09:59 +0200)
committerHeiko Schocher <hs@denx.de>
Tue, 28 Jul 2009 06:20:58 +0000 (08:20 +0200)
Signed-off-by: Heiko Schocher <hs@denx.de>
drivers/i2c/Makefile
drivers/i2c/kirkwood_i2c.c [new file with mode: 0644]

index ef32f13377616a6d1afee7d16dd308abb39181fb..4a12976e376fac5b90809cba20e1f03fe96f389b 100644 (file)
@@ -28,6 +28,7 @@ LIB   := $(obj)libi2c.a
 COBJS-$(CONFIG_BFIN_TWI_I2C) += bfin-twi_i2c.o
 COBJS-$(CONFIG_DRIVER_DAVINCI_I2C) += davinci_i2c.o
 COBJS-$(CONFIG_FSL_I2C) += fsl_i2c.o
+COBJS-$(CONFIG_I2C_KIRKWOOD) += kirkwood_i2c.o
 COBJS-$(CONFIG_I2C_MXC) += mxc_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP1510_I2C) += omap1510_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP24XX_I2C) += omap24xx_i2c.o
diff --git a/drivers/i2c/kirkwood_i2c.c b/drivers/i2c/kirkwood_i2c.c
new file mode 100644 (file)
index 0000000..dd30499
--- /dev/null
@@ -0,0 +1,484 @@
+/*
+ * Driver for the i2c controller on the Marvell line of host bridges
+ * (e.g, gt642[46]0, mv643[46]0, mv644[46]0, Orion SoC family),
+ * and Kirkwood family.
+ *
+ * Based on:
+ * Author: Mark A. Greer <mgreer@mvista.com>
+ *
+ * 2005 (c) MontaVista, Software, Inc.  This file is licensed under
+ * the terms of the GNU General Public License version 2.  This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ *
+ * ported from Linux to u-boot
+ * (C) Copyright 2009
+ * Heiko Schocher, DENX Software Engineering, hs@denx.de.
+ *
+ */
+#include <common.h>
+#include <i2c.h>
+#include <asm/arch/kirkwood.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static unsigned int i2c_bus_num __attribute__ ((section (".data"))) = 0;
+#if defined(CONFIG_I2C_MUX)
+static unsigned int i2c_bus_num_mux __attribute__ ((section ("data"))) = 0;
+#endif
+
+/* Register defines */
+#define        KW_I2C_REG_SLAVE_ADDR                   0x00
+#define        KW_I2C_REG_DATA                         0x04
+#define        KW_I2C_REG_CONTROL                      0x08
+#define        KW_I2C_REG_STATUS                       0x0c
+#define        KW_I2C_REG_BAUD                         0x0c
+#define        KW_I2C_REG_EXT_SLAVE_ADDR               0x10
+#define        KW_I2C_REG_SOFT_RESET                   0x1c
+
+#define        KW_I2C_REG_CONTROL_ACK                  0x00000004
+#define        KW_I2C_REG_CONTROL_IFLG                 0x00000008
+#define        KW_I2C_REG_CONTROL_STOP                 0x00000010
+#define        KW_I2C_REG_CONTROL_START                0x00000020
+#define        KW_I2C_REG_CONTROL_TWSIEN               0x00000040
+#define        KW_I2C_REG_CONTROL_INTEN                0x00000080
+
+/* Ctlr status values */
+#define        KW_I2C_STATUS_BUS_ERR                   0x00
+#define        KW_I2C_STATUS_MAST_START                0x08
+#define        KW_I2C_STATUS_MAST_REPEAT_START         0x10
+#define        KW_I2C_STATUS_MAST_WR_ADDR_ACK          0x18
+#define        KW_I2C_STATUS_MAST_WR_ADDR_NO_ACK       0x20
+#define        KW_I2C_STATUS_MAST_WR_ACK               0x28
+#define        KW_I2C_STATUS_MAST_WR_NO_ACK            0x30
+#define        KW_I2C_STATUS_MAST_LOST_ARB             0x38
+#define        KW_I2C_STATUS_MAST_RD_ADDR_ACK          0x40
+#define        KW_I2C_STATUS_MAST_RD_ADDR_NO_ACK       0x48
+#define        KW_I2C_STATUS_MAST_RD_DATA_ACK          0x50
+#define        KW_I2C_STATUS_MAST_RD_DATA_NO_ACK       0x58
+#define        KW_I2C_STATUS_MAST_WR_ADDR_2_ACK        0xd0
+#define        KW_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK     0xd8
+#define        KW_I2C_STATUS_MAST_RD_ADDR_2_ACK        0xe0
+#define        KW_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK     0xe8
+#define        KW_I2C_STATUS_NO_STATUS                 0xf8
+
+/* Driver states */
+enum {
+       KW_I2C_STATE_INVALID,
+       KW_I2C_STATE_IDLE,
+       KW_I2C_STATE_WAITING_FOR_START_COND,
+       KW_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
+       KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
+       KW_I2C_STATE_WAITING_FOR_SLAVE_ACK,
+       KW_I2C_STATE_WAITING_FOR_SLAVE_DATA,
+};
+
+/* Driver actions */
+enum {
+       KW_I2C_ACTION_INVALID,
+       KW_I2C_ACTION_CONTINUE,
+       KW_I2C_ACTION_SEND_START,
+       KW_I2C_ACTION_SEND_ADDR_1,
+       KW_I2C_ACTION_SEND_ADDR_2,
+       KW_I2C_ACTION_SEND_DATA,
+       KW_I2C_ACTION_RCV_DATA,
+       KW_I2C_ACTION_RCV_DATA_STOP,
+       KW_I2C_ACTION_SEND_STOP,
+};
+
+/* defines to get compatible with Linux driver */
+#define IRQ_NONE       0x0
+#define IRQ_HANDLED    0x01
+
+#define I2C_M_TEN      0x01
+#define I2C_M_RD       0x02
+#define        I2C_M_REV_DIR_ADDR      0x04;
+
+struct i2c_msg {
+       u32     addr;
+       u32     flags;
+       u8      *buf;
+       u32     len;
+};
+
+struct kirkwood_i2c_data {
+       int                     irq;
+       u32                     state;
+       u32                     action;
+       u32                     aborting;
+       u32                     cntl_bits;
+       void                    *reg_base;
+       u32                     reg_base_p;
+       u32                     reg_size;
+       u32                     addr1;
+       u32                     addr2;
+       u32                     bytes_left;
+       u32                     byte_posn;
+       u32                     block;
+       int                     rc;
+       u32                     freq_m;
+       u32                     freq_n;
+       struct i2c_msg          *msg;
+};
+
+static struct kirkwood_i2c_data __drv_data __attribute__ ((section (".data")));
+static struct kirkwood_i2c_data *drv_data = &__drv_data;
+static struct i2c_msg __i2c_msg __attribute__ ((section (".data")));
+static struct i2c_msg *kirkwood_i2c_msg = &__i2c_msg;
+
+/*
+ *****************************************************************************
+ *
+ *     Finite State Machine & Interrupt Routines
+ *
+ *****************************************************************************
+ */
+
+static inline int abs(int n)
+{
+        if(n >= 0)
+               return n;
+       else
+               return n * -1;
+}
+
+static void kirkwood_calculate_speed(int speed)
+{
+       int     calcspeed;
+       int     diff;
+       int     best_diff = CONFIG_SYS_TCLK;
+       int     best_speed = 0;
+       int     m, n;
+       int     tmp[8] = {2, 4, 8, 16, 32, 64, 128, 256};
+
+       for (n = 0; n < 8; n++) {
+               for (m = 0; m < 16; m++) {
+                       calcspeed = CONFIG_SYS_TCLK / (10 * (m + 1) * tmp[n]);
+                       diff = abs((speed - calcspeed));
+                       if ( diff < best_diff) {
+                               best_diff = diff;
+                               best_speed = calcspeed;
+                               drv_data->freq_m = m;
+                               drv_data->freq_n = n;
+                       }
+               }
+       }
+}
+
+/* Reset hardware and initialize FSM */
+static void
+kirkwood_i2c_hw_init(int speed, int slaveadd)
+{
+       drv_data->state = KW_I2C_STATE_IDLE;
+
+       kirkwood_calculate_speed(speed);
+       writel(0, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_SOFT_RESET);
+       writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
+               CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_BAUD);
+       writel(slaveadd, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_SLAVE_ADDR);
+       writel(0, CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_EXT_SLAVE_ADDR);
+       writel(KW_I2C_REG_CONTROL_TWSIEN | KW_I2C_REG_CONTROL_STOP,
+               CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+}
+
+static void
+kirkwood_i2c_fsm(u32 status)
+{
+       /*
+        * If state is idle, then this is likely the remnants of an old
+        * operation that driver has given up on or the user has killed.
+        * If so, issue the stop condition and go to idle.
+        */
+       if (drv_data->state == KW_I2C_STATE_IDLE) {
+               drv_data->action = KW_I2C_ACTION_SEND_STOP;
+               return;
+       }
+
+       /* The status from the ctlr [mostly] tells us what to do next */
+       switch (status) {
+       /* Start condition interrupt */
+       case KW_I2C_STATUS_MAST_START: /* 0x08 */
+       case KW_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
+               drv_data->action = KW_I2C_ACTION_SEND_ADDR_1;
+               drv_data->state = KW_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
+               break;
+
+       /* Performing a write */
+       case KW_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
+               if (drv_data->msg->flags & I2C_M_TEN) {
+                       drv_data->action = KW_I2C_ACTION_SEND_ADDR_2;
+                       drv_data->state =
+                               KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
+                       break;
+               }
+               /* FALLTHRU */
+       case KW_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
+       case KW_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
+               if ((drv_data->bytes_left == 0)
+                               || (drv_data->aborting
+                                       && (drv_data->byte_posn != 0))) {
+                       drv_data->action = KW_I2C_ACTION_SEND_STOP;
+                       drv_data->state = KW_I2C_STATE_IDLE;
+               } else {
+                       drv_data->action = KW_I2C_ACTION_SEND_DATA;
+                       drv_data->state =
+                               KW_I2C_STATE_WAITING_FOR_SLAVE_ACK;
+                       drv_data->bytes_left--;
+               }
+               break;
+
+       /* Performing a read */
+       case KW_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
+               if (drv_data->msg->flags & I2C_M_TEN) {
+                       drv_data->action = KW_I2C_ACTION_SEND_ADDR_2;
+                       drv_data->state =
+                               KW_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
+                       break;
+               }
+               /* FALLTHRU */
+       case KW_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
+               if (drv_data->bytes_left == 0) {
+                       drv_data->action = KW_I2C_ACTION_SEND_STOP;
+                       drv_data->state = KW_I2C_STATE_IDLE;
+                       break;
+               }
+               /* FALLTHRU */
+       case KW_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
+               if (status != KW_I2C_STATUS_MAST_RD_DATA_ACK)
+                       drv_data->action = KW_I2C_ACTION_CONTINUE;
+               else {
+                       drv_data->action = KW_I2C_ACTION_RCV_DATA;
+                       drv_data->bytes_left--;
+               }
+               drv_data->state = KW_I2C_STATE_WAITING_FOR_SLAVE_DATA;
+
+               if ((drv_data->bytes_left == 1) || drv_data->aborting)
+                       drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_ACK;
+               break;
+
+       case KW_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
+               drv_data->action = KW_I2C_ACTION_RCV_DATA_STOP;
+               drv_data->state = KW_I2C_STATE_IDLE;
+               break;
+
+       case KW_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
+       case KW_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
+       case KW_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
+               /* Doesn't seem to be a device at other end */
+               drv_data->action = KW_I2C_ACTION_SEND_STOP;
+               drv_data->state = KW_I2C_STATE_IDLE;
+               drv_data->rc = -ENODEV;
+               break;
+
+       default:
+               printf("kirkwood_i2c_fsm: Ctlr Error -- state: 0x%x, "
+                       "status: 0x%x, addr: 0x%x, flags: 0x%x\n",
+                        drv_data->state, status, drv_data->msg->addr,
+                        drv_data->msg->flags);
+               drv_data->action = KW_I2C_ACTION_SEND_STOP;
+               kirkwood_i2c_hw_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
+               drv_data->rc = -EIO;
+       }
+}
+
+static void
+kirkwood_i2c_do_action(void)
+{
+       switch(drv_data->action) {
+       case KW_I2C_ACTION_CONTINUE:
+               writel(drv_data->cntl_bits,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               break;
+
+       case KW_I2C_ACTION_SEND_START:
+               writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_START,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               break;
+
+       case KW_I2C_ACTION_SEND_ADDR_1:
+               writel(drv_data->addr1,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+               writel(drv_data->cntl_bits,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               break;
+
+       case KW_I2C_ACTION_SEND_ADDR_2:
+               writel(drv_data->addr2,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+               writel(drv_data->cntl_bits,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               break;
+
+       case KW_I2C_ACTION_SEND_DATA:
+               writel(drv_data->msg->buf[drv_data->byte_posn++],
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+               writel(drv_data->cntl_bits,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               break;
+
+       case KW_I2C_ACTION_RCV_DATA:
+               drv_data->msg->buf[drv_data->byte_posn++] =
+                       readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+               writel(drv_data->cntl_bits,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               break;
+
+       case KW_I2C_ACTION_RCV_DATA_STOP:
+               drv_data->msg->buf[drv_data->byte_posn++] =
+                       readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_DATA);
+               drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_INTEN;
+               writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_STOP,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               drv_data->block = 0;
+               break;
+
+       case KW_I2C_ACTION_INVALID:
+       default:
+               printf("kirkwood_i2c_do_action: Invalid action: %d\n",
+                       drv_data->action);
+               drv_data->rc = -EIO;
+               /* FALLTHRU */
+       case KW_I2C_ACTION_SEND_STOP:
+               drv_data->cntl_bits &= ~KW_I2C_REG_CONTROL_INTEN;
+               writel(drv_data->cntl_bits | KW_I2C_REG_CONTROL_STOP,
+                       CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               drv_data->block = 0;
+               break;
+       }
+}
+
+static int
+kirkwood_i2c_intr(void)
+{
+       u32             status;
+       u32             ctrl;
+       int             rc = IRQ_NONE;
+
+       ctrl = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+       while ((ctrl & KW_I2C_REG_CONTROL_IFLG) &&
+               (drv_data->rc == 0)) {
+               status = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_STATUS);
+               kirkwood_i2c_fsm(status);
+               kirkwood_i2c_do_action();
+               rc = IRQ_HANDLED;
+               ctrl = readl(CONFIG_I2C_KW_REG_BASE + KW_I2C_REG_CONTROL);
+               udelay(1000);
+       }
+       return rc;
+}
+
+static void
+kirkwood_i2c_doio(struct i2c_msg *msg)
+{
+       int     ret;
+
+       while ((drv_data->rc == 0) && (drv_data->state != KW_I2C_STATE_IDLE)) {
+               /* poll Status register */
+               ret = kirkwood_i2c_intr();
+               if (ret == IRQ_NONE)
+                       udelay(10);
+       }
+}
+
+static void
+kirkwood_i2c_prepare_for_io(struct i2c_msg *msg)
+{
+       u32     dir = 0;
+
+       drv_data->msg = msg;
+       drv_data->byte_posn = 0;
+       drv_data->bytes_left = msg->len;
+       drv_data->aborting = 0;
+       drv_data->rc = 0;
+       /* in u-boot we use no IRQs */
+       drv_data->cntl_bits = KW_I2C_REG_CONTROL_ACK | KW_I2C_REG_CONTROL_TWSIEN;
+
+       if (msg->flags & I2C_M_RD)
+               dir = 1;
+       if (msg->flags & I2C_M_TEN) {
+               drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
+               drv_data->addr2 = (u32)msg->addr & 0xff;
+       } else {
+               drv_data->addr1 = ((u32)msg->addr & 0x7f) << 1 | dir;
+               drv_data->addr2 = 0;
+       }
+       /* OK, no start it (from kirkwood_i2c_execute_msg())*/
+       drv_data->action = KW_I2C_ACTION_SEND_START;
+       drv_data->state = KW_I2C_STATE_WAITING_FOR_START_COND;
+       drv_data->block = 1;
+       kirkwood_i2c_do_action();
+}
+
+void
+i2c_init(int speed, int slaveadd)
+{
+       kirkwood_i2c_hw_init(speed, slaveadd);
+}
+
+int
+i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+       kirkwood_i2c_msg->buf = data;
+       kirkwood_i2c_msg->len = length;
+       kirkwood_i2c_msg->addr = dev;
+       kirkwood_i2c_msg->flags = I2C_M_RD;
+
+       kirkwood_i2c_prepare_for_io(kirkwood_i2c_msg);
+       kirkwood_i2c_doio(kirkwood_i2c_msg);
+       return drv_data->rc;
+}
+
+int
+i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+       kirkwood_i2c_msg->buf = data;
+       kirkwood_i2c_msg->len = length;
+       kirkwood_i2c_msg->addr = dev;
+       kirkwood_i2c_msg->flags = 0;
+
+       kirkwood_i2c_prepare_for_io(kirkwood_i2c_msg);
+       kirkwood_i2c_doio(kirkwood_i2c_msg);
+       return drv_data->rc;
+}
+
+int
+i2c_probe(uchar chip)
+{
+       return i2c_read(chip, 0, 0, NULL, 0);
+}
+
+int i2c_set_bus_num(unsigned int bus)
+{
+#if defined(CONFIG_I2C_MUX)
+       if (bus < CONFIG_SYS_MAX_I2C_BUS) {
+               i2c_bus_num = bus;
+       } else {
+               int     ret;
+
+               ret = i2x_mux_select_mux(bus);
+               if (ret)
+                       return ret;
+               i2c_bus_num = 0;
+       }
+       i2c_bus_num_mux = bus;
+#else
+       if (bus > 0) {
+               return -1;
+       }
+
+       i2c_bus_num = bus;
+#endif
+       return 0;
+}
+
+unsigned int i2c_get_bus_num(void)
+{
+#if defined(CONFIG_I2C_MUX)
+       return i2c_bus_num_mux;
+#else
+       return i2c_bus_num;
+#endif
+}
+