summaryrefslogtreecommitdiff
path: root/drivers/i2c/mv_i2c.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/i2c/mv_i2c.c')
-rw-r--r--drivers/i2c/mv_i2c.c481
1 files changed, 481 insertions, 0 deletions
diff --git a/drivers/i2c/mv_i2c.c b/drivers/i2c/mv_i2c.c
new file mode 100644
index 0000000..dcbe1ae
--- /dev/null
+++ b/drivers/i2c/mv_i2c.c
@@ -0,0 +1,481 @@
+/*
+ * (C) Copyright 2000
+ * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it
+ *
+ * (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Marius Groeger <mgroeger@sysgo.de>
+ *
+ * (C) Copyright 2003 Pengutronix e.K.
+ * Robert Schwebel <r.schwebel@pengutronix.de>
+ *
+ * (C) Copyright 2011 Marvell Inc.
+ * Lei Wen <leiwen@marvell.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ * Back ported to the 8xx platform (from the 8260 platform) by
+ * Murray.Jensen@cmst.csiro.au, 27-Jan-01.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_HARD_I2C
+#include <i2c.h>
+#include "mv_i2c.h"
+
+#ifdef DEBUG_I2C
+#define PRINTD(x) printf x
+#else
+#define PRINTD(x)
+#endif
+
+/* All transfers are described by this data structure */
+struct i2c_msg {
+ u8 condition;
+ u8 acknack;
+ u8 direction;
+ u8 data;
+};
+
+struct mv_i2c {
+ u32 ibmr;
+ u32 pad0;
+ u32 idbr;
+ u32 pad1;
+ u32 icr;
+ u32 pad2;
+ u32 isr;
+ u32 pad3;
+ u32 isar;
+};
+
+static struct mv_i2c *base;
+#ifdef CONFIG_I2C_MULTI_BUS
+static u32 i2c_regs[CONFIG_MV_I2C_NUM] = CONFIG_MV_I2C_REG;
+static unsigned int bus_initialized[CONFIG_MV_I2C_NUM];
+static unsigned int current_bus;
+
+int i2c_set_bus_num(unsigned int bus)
+{
+ if ((bus < 0) || (bus >= CONFIG_MV_I2C_NUM)) {
+ printf("Bad bus: %d\n", bus);
+ return -1;
+ }
+
+ base = (struct mv_i2c *)i2c_regs[bus];
+ current_bus = bus;
+
+ if (!bus_initialized[current_bus]) {
+ i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
+ bus_initialized[current_bus] = 1;
+ }
+
+ return 0;
+}
+
+unsigned int i2c_get_bus_num(void)
+{
+ return current_bus;
+}
+#endif
+
+/*
+ * i2c_reset: - reset the host controller
+ *
+ */
+static void i2c_reset(void)
+{
+ writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
+ writel(readl(&base->icr) | ICR_UR, &base->icr); /* reset the unit */
+ udelay(100);
+ writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */
+
+ i2c_clk_enable();
+
+ writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */
+ writel(I2C_ICR_INIT, &base->icr); /* set control reg values */
+ writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */
+ writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */
+ udelay(100);
+}
+
+/*
+ * i2c_isr_set_cleared: - wait until certain bits of the I2C status register
+ * are set and cleared
+ *
+ * @return: 1 in case of success, 0 means timeout (no match within 10 ms).
+ */
+static int i2c_isr_set_cleared(unsigned long set_mask,
+ unsigned long cleared_mask)
+{
+ int timeout = 1000, isr;
+
+ do {
+ isr = readl(&base->isr);
+ udelay(10);
+ if (timeout-- < 0)
+ return 0;
+ } while (((isr & set_mask) != set_mask)
+ || ((isr & cleared_mask) != 0));
+
+ return 1;
+}
+
+/*
+ * i2c_transfer: - Transfer one byte over the i2c bus
+ *
+ * This function can tranfer a byte over the i2c bus in both directions.
+ * It is used by the public API functions.
+ *
+ * @return: 0: transfer successful
+ * -1: message is empty
+ * -2: transmit timeout
+ * -3: ACK missing
+ * -4: receive timeout
+ * -5: illegal parameters
+ * -6: bus is busy and couldn't be aquired
+ */
+int i2c_transfer(struct i2c_msg *msg)
+{
+ int ret;
+
+ if (!msg)
+ goto transfer_error_msg_empty;
+
+ switch (msg->direction) {
+ case I2C_WRITE:
+ /* check if bus is not busy */
+ if (!i2c_isr_set_cleared(0, ISR_IBB))
+ goto transfer_error_bus_busy;
+
+ /* start transmission */
+ writel(readl(&base->icr) & ~ICR_START, &base->icr);
+ writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
+ writel(msg->data, &base->idbr);
+ if (msg->condition == I2C_COND_START)
+ writel(readl(&base->icr) | ICR_START, &base->icr);
+ if (msg->condition == I2C_COND_STOP)
+ writel(readl(&base->icr) | ICR_STOP, &base->icr);
+ if (msg->acknack == I2C_ACKNAK_SENDNAK)
+ writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
+ if (msg->acknack == I2C_ACKNAK_SENDACK)
+ writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
+ writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
+ writel(readl(&base->icr) | ICR_TB, &base->icr);
+
+ /* transmit register empty? */
+ if (!i2c_isr_set_cleared(ISR_ITE, 0))
+ goto transfer_error_transmit_timeout;
+
+ /* clear 'transmit empty' state */
+ writel(readl(&base->isr) | ISR_ITE, &base->isr);
+
+ /* wait for ACK from slave */
+ if (msg->acknack == I2C_ACKNAK_WAITACK)
+ if (!i2c_isr_set_cleared(0, ISR_ACKNAK))
+ goto transfer_error_ack_missing;
+ break;
+
+ case I2C_READ:
+
+ /* check if bus is not busy */
+ if (!i2c_isr_set_cleared(0, ISR_IBB))
+ goto transfer_error_bus_busy;
+
+ /* start receive */
+ writel(readl(&base->icr) & ~ICR_START, &base->icr);
+ writel(readl(&base->icr) & ~ICR_STOP, &base->icr);
+ if (msg->condition == I2C_COND_START)
+ writel(readl(&base->icr) | ICR_START, &base->icr);
+ if (msg->condition == I2C_COND_STOP)
+ writel(readl(&base->icr) | ICR_STOP, &base->icr);
+ if (msg->acknack == I2C_ACKNAK_SENDNAK)
+ writel(readl(&base->icr) | ICR_ACKNAK, &base->icr);
+ if (msg->acknack == I2C_ACKNAK_SENDACK)
+ writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr);
+ writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr);
+ writel(readl(&base->icr) | ICR_TB, &base->icr);
+
+ /* receive register full? */
+ if (!i2c_isr_set_cleared(ISR_IRF, 0))
+ goto transfer_error_receive_timeout;
+
+ msg->data = readl(&base->idbr);
+
+ /* clear 'receive empty' state */
+ writel(readl(&base->isr) | ISR_IRF, &base->isr);
+ break;
+ default:
+ goto transfer_error_illegal_param;
+ }
+
+ return 0;
+
+transfer_error_msg_empty:
+ PRINTD(("i2c_transfer: error: 'msg' is empty\n"));
+ ret = -1; goto i2c_transfer_finish;
+
+transfer_error_transmit_timeout:
+ PRINTD(("i2c_transfer: error: transmit timeout\n"));
+ ret = -2; goto i2c_transfer_finish;
+
+transfer_error_ack_missing:
+ PRINTD(("i2c_transfer: error: ACK missing\n"));
+ ret = -3; goto i2c_transfer_finish;
+
+transfer_error_receive_timeout:
+ PRINTD(("i2c_transfer: error: receive timeout\n"));
+ ret = -4; goto i2c_transfer_finish;
+
+transfer_error_illegal_param:
+ PRINTD(("i2c_transfer: error: illegal parameters\n"));
+ ret = -5; goto i2c_transfer_finish;
+
+transfer_error_bus_busy:
+ PRINTD(("i2c_transfer: error: bus is busy\n"));
+ ret = -6; goto i2c_transfer_finish;
+
+i2c_transfer_finish:
+ PRINTD(("i2c_transfer: ISR: 0x%04x\n", ISR));
+ i2c_reset();
+ return ret;
+}
+
+/* ------------------------------------------------------------------------ */
+/* API Functions */
+/* ------------------------------------------------------------------------ */
+void i2c_init(int speed, int slaveaddr)
+{
+#ifdef CONFIG_I2C_MULTI_BUS
+ base = (struct mv_i2c *)i2c_regs[current_bus];
+#else
+ base = (struct mv_i2c *)CONFIG_MV_I2C_REG;
+#endif
+
+#ifdef CONFIG_SYS_I2C_INIT_BOARD
+ u32 icr;
+ /*
+ * call board specific i2c bus reset routine before accessing the
+ * environment, which might be in a chip on that bus. For details
+ * about this problem see doc/I2C_Edge_Conditions.
+ *
+ * disable I2C controller first, otherwhise it thinks we want to
+ * talk to the slave port...
+ */
+ icr = readl(&base->icr);
+ writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr);
+
+ i2c_init_board();
+
+ writel(icr, &base->icr);
+#endif
+}
+
+/*
+ * i2c_probe: - Test if a chip answers for a given i2c address
+ *
+ * @chip: address of the chip which is searched for
+ * @return: 0 if a chip was found, -1 otherwhise
+ */
+int i2c_probe(uchar chip)
+{
+ struct i2c_msg msg;
+
+ i2c_reset();
+
+ msg.condition = I2C_COND_START;
+ msg.acknack = I2C_ACKNAK_WAITACK;
+ msg.direction = I2C_WRITE;
+ msg.data = (chip << 1) + 1;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ msg.condition = I2C_COND_STOP;
+ msg.acknack = I2C_ACKNAK_SENDNAK;
+ msg.direction = I2C_READ;
+ msg.data = 0x00;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ return 0;
+}
+
+/*
+ * i2c_read: - Read multiple bytes from an i2c device
+ *
+ * The higher level routines take into account that this function is only
+ * called with len < page length of the device (see configuration file)
+ *
+ * @chip: address of the chip which is to be read
+ * @addr: i2c data address within the chip
+ * @alen: length of the i2c data address (1..2 bytes)
+ * @buffer: where to write the data
+ * @len: how much byte do we want to read
+ * @return: 0 in case of success
+ */
+int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+ struct i2c_msg msg;
+ u8 addr_bytes[3]; /* lowest...highest byte of data address */
+
+ PRINTD(("i2c_read(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
+ "len=0x%02x)\n", chip, addr, alen, len));
+
+ i2c_reset();
+
+ /* dummy chip address write */
+ PRINTD(("i2c_read: dummy chip address write\n"));
+ msg.condition = I2C_COND_START;
+ msg.acknack = I2C_ACKNAK_WAITACK;
+ msg.direction = I2C_WRITE;
+ msg.data = (chip << 1);
+ msg.data &= 0xFE;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ /*
+ * send memory address bytes;
+ * alen defines how much bytes we have to send.
+ */
+ /*addr &= ((1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)-1); */
+ addr_bytes[0] = (u8)((addr >> 0) & 0x000000FF);
+ addr_bytes[1] = (u8)((addr >> 8) & 0x000000FF);
+ addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
+
+ while (--alen >= 0) {
+ PRINTD(("i2c_read: send memory word address byte %1d\n", alen));
+ msg.condition = I2C_COND_NORMAL;
+ msg.acknack = I2C_ACKNAK_WAITACK;
+ msg.direction = I2C_WRITE;
+ msg.data = addr_bytes[alen];
+ if (i2c_transfer(&msg))
+ return -1;
+ }
+
+ /* start read sequence */
+ PRINTD(("i2c_read: start read sequence\n"));
+ msg.condition = I2C_COND_START;
+ msg.acknack = I2C_ACKNAK_WAITACK;
+ msg.direction = I2C_WRITE;
+ msg.data = (chip << 1);
+ msg.data |= 0x01;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ /* read bytes; send NACK at last byte */
+ while (len--) {
+ if (len == 0) {
+ msg.condition = I2C_COND_STOP;
+ msg.acknack = I2C_ACKNAK_SENDNAK;
+ } else {
+ msg.condition = I2C_COND_NORMAL;
+ msg.acknack = I2C_ACKNAK_SENDACK;
+ }
+
+ msg.direction = I2C_READ;
+ msg.data = 0x00;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ *buffer = msg.data;
+ PRINTD(("i2c_read: reading byte (0x%08x)=0x%02x\n",
+ (unsigned int)buffer, *buffer));
+ buffer++;
+ }
+
+ i2c_reset();
+
+ return 0;
+}
+
+/*
+ * i2c_write: - Write multiple bytes to an i2c device
+ *
+ * The higher level routines take into account that this function is only
+ * called with len < page length of the device (see configuration file)
+ *
+ * @chip: address of the chip which is to be written
+ * @addr: i2c data address within the chip
+ * @alen: length of the i2c data address (1..2 bytes)
+ * @buffer: where to find the data to be written
+ * @len: how much byte do we want to read
+ * @return: 0 in case of success
+ */
+int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+ struct i2c_msg msg;
+ u8 addr_bytes[3]; /* lowest...highest byte of data address */
+
+ PRINTD(("i2c_write(chip=0x%02x, addr=0x%02x, alen=0x%02x, "
+ "len=0x%02x)\n", chip, addr, alen, len));
+
+ i2c_reset();
+
+ /* chip address write */
+ PRINTD(("i2c_write: chip address write\n"));
+ msg.condition = I2C_COND_START;
+ msg.acknack = I2C_ACKNAK_WAITACK;
+ msg.direction = I2C_WRITE;
+ msg.data = (chip << 1);
+ msg.data &= 0xFE;
+ if (i2c_transfer(&msg))
+ return -1;
+
+ /*
+ * send memory address bytes;
+ * alen defines how much bytes we have to send.
+ */
+ addr_bytes[0] = (u8)((addr >> 0) & 0x000000FF);
+ addr_bytes[1] = (u8)((addr >> 8) & 0x000000FF);
+ addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF);
+
+ while (--alen >= 0) {
+ PRINTD(("i2c_write: send memory word address\n"));
+ msg.condition = I2C_COND_NORMAL;
+ msg.acknack = I2C_ACKNAK_WAITACK;
+ msg.direction = I2C_WRITE;
+ msg.data = addr_bytes[alen];
+ if (i2c_transfer(&msg))
+ return -1;
+ }
+
+ /* write bytes; send NACK at last byte */
+ while (len--) {
+ PRINTD(("i2c_write: writing byte (0x%08x)=0x%02x\n",
+ (unsigned int)buffer, *buffer));
+
+ if (len == 0)
+ msg.condition = I2C_COND_STOP;
+ else
+ msg.condition = I2C_COND_NORMAL;
+
+ msg.acknack = I2C_ACKNAK_WAITACK;
+ msg.direction = I2C_WRITE;
+ msg.data = *(buffer++);
+
+ if (i2c_transfer(&msg))
+ return -1;
+ }
+
+ i2c_reset();
+
+ return 0;
+}
+#endif /* CONFIG_HARD_I2C */
generated by cgit v1.1 at 2024-08-27 06:59:14 +0000