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Diffstat (limited to 'drivers/i2c/ppc4xx_i2c.c')
-rw-r--r--drivers/i2c/ppc4xx_i2c.c439
1 files changed, 439 insertions, 0 deletions
diff --git a/drivers/i2c/ppc4xx_i2c.c b/drivers/i2c/ppc4xx_i2c.c
new file mode 100644
index 0000000..9b86187
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+++ b/drivers/i2c/ppc4xx_i2c.c
@@ -0,0 +1,439 @@
+/*
+ * (C) Copyright 2007-2009
+ * Stefan Roese, DENX Software Engineering, sr@denx.de.
+ *
+ * based on work by Anne Sophie Harnois <anne-sophie.harnois@nextream.fr>
+ *
+ * (C) Copyright 2001
+ * Bill Hunter, Wave 7 Optics, williamhunter@mediaone.net
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <ppc4xx.h>
+#include <4xx_i2c.h>
+#include <i2c.h>
+#include <asm-ppc/io.h>
+
+#ifdef CONFIG_HARD_I2C
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#if defined(CONFIG_I2C_MULTI_BUS)
+/*
+ * Initialize the bus pointer to whatever one the SPD EEPROM is on.
+ * Default is bus 0. This is necessary because the DDR initialization
+ * runs from ROM, and we can't switch buses because we can't modify
+ * the global variables.
+ */
+#ifndef CONFIG_SYS_SPD_BUS_NUM
+#define CONFIG_SYS_SPD_BUS_NUM 0
+#endif
+static unsigned int i2c_bus_num __attribute__ ((section (".data"))) =
+ CONFIG_SYS_SPD_BUS_NUM;
+#endif /* CONFIG_I2C_MULTI_BUS */
+
+static void _i2c_bus_reset(void)
+{
+ struct ppc4xx_i2c *i2c = (struct ppc4xx_i2c *)I2C_BASE_ADDR;
+ int i;
+ u8 dc;
+
+ /* Reset status register */
+ /* write 1 in SCMP and IRQA to clear these fields */
+ out_8(&i2c->sts, 0x0A);
+
+ /* write 1 in IRQP IRQD LA ICT XFRA to clear these fields */
+ out_8(&i2c->extsts, 0x8F);
+
+ /* Place chip in the reset state */
+ out_8(&i2c->xtcntlss, IIC_XTCNTLSS_SRST);
+
+ /* Check if bus is free */
+ dc = in_8(&i2c->directcntl);
+ if (!DIRCTNL_FREE(dc)){
+ /* Try to set bus free state */
+ out_8(&i2c->directcntl, IIC_DIRCNTL_SDAC | IIC_DIRCNTL_SCC);
+
+ /* Wait until we regain bus control */
+ for (i = 0; i < 100; ++i) {
+ dc = in_8(&i2c->directcntl);
+ if (DIRCTNL_FREE(dc))
+ break;
+
+ /* Toggle SCL line */
+ dc ^= IIC_DIRCNTL_SCC;
+ out_8(&i2c->directcntl, dc);
+ udelay(10);
+ dc ^= IIC_DIRCNTL_SCC;
+ out_8(&i2c->directcntl, dc);
+ }
+ }
+
+ /* Remove reset */
+ out_8(&i2c->xtcntlss, 0);
+}
+
+void i2c_init(int speed, int slaveaddr)
+{
+ struct ppc4xx_i2c *i2c;
+ int val, divisor;
+ int bus;
+
+#ifdef CONFIG_SYS_I2C_INIT_BOARD
+ /*
+ * 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.
+ */
+ i2c_init_board();
+#endif
+
+ for (bus = 0; bus < CONFIG_SYS_MAX_I2C_BUS; bus++) {
+ I2C_SET_BUS(bus);
+
+ /* Set i2c pointer after calling I2C_SET_BUS() */
+ i2c = (struct ppc4xx_i2c *)I2C_BASE_ADDR;
+
+ /* Handle possible failed I2C state */
+ /* FIXME: put this into i2c_init_board()? */
+ _i2c_bus_reset();
+
+ /* clear lo master address */
+ out_8(&i2c->lmadr, 0);
+
+ /* clear hi master address */
+ out_8(&i2c->hmadr, 0);
+
+ /* clear lo slave address */
+ out_8(&i2c->lsadr, 0);
+
+ /* clear hi slave address */
+ out_8(&i2c->hsadr, 0);
+
+ /* Clock divide Register */
+ /* set divisor according to freq_opb */
+ divisor = (get_OPB_freq() - 1) / 10000000;
+ if (divisor == 0)
+ divisor = 1;
+ out_8(&i2c->clkdiv, divisor);
+
+ /* no interrupts */
+ out_8(&i2c->intrmsk, 0);
+
+ /* clear transfer count */
+ out_8(&i2c->xfrcnt, 0);
+
+ /* clear extended control & stat */
+ /* write 1 in SRC SRS SWC SWS to clear these fields */
+ out_8(&i2c->xtcntlss, 0xF0);
+
+ /* Mode Control Register
+ Flush Slave/Master data buffer */
+ out_8(&i2c->mdcntl, IIC_MDCNTL_FSDB | IIC_MDCNTL_FMDB);
+
+ val = in_8(&i2c->mdcntl);
+
+ /* Ignore General Call, slave transfers are ignored,
+ * disable interrupts, exit unknown bus state, enable hold
+ * SCL 100kHz normaly or FastMode for 400kHz and above
+ */
+
+ val |= IIC_MDCNTL_EUBS | IIC_MDCNTL_HSCL;
+ if (speed >= 400000)
+ val |= IIC_MDCNTL_FSM;
+ out_8(&i2c->mdcntl, val);
+
+ /* clear control reg */
+ out_8(&i2c->cntl, 0x00);
+ }
+
+ /* set to SPD bus as default bus upon powerup */
+ I2C_SET_BUS(CONFIG_SYS_SPD_BUS_NUM);
+}
+
+/*
+ * This code tries to use the features of the 405GP i2c
+ * controller. It will transfer up to 4 bytes in one pass
+ * on the loop. It only does out_8((u8 *)lbz) to the buffer when it
+ * is possible to do out16(lhz) transfers.
+ *
+ * cmd_type is 0 for write 1 for read.
+ *
+ * addr_len can take any value from 0-255, it is only limited
+ * by the char, we could make it larger if needed. If it is
+ * 0 we skip the address write cycle.
+ *
+ * Typical case is a Write of an addr followd by a Read. The
+ * IBM FAQ does not cover this. On the last byte of the write
+ * we don't set the creg CHT bit, and on the first bytes of the
+ * read we set the RPST bit.
+ *
+ * It does not support address only transfers, there must be
+ * a data part. If you want to write the address yourself, put
+ * it in the data pointer.
+ *
+ * It does not support transfer to/from address 0.
+ *
+ * It does not check XFRCNT.
+ */
+static int i2c_transfer(unsigned char cmd_type,
+ unsigned char chip,
+ unsigned char addr[],
+ unsigned char addr_len,
+ unsigned char data[],
+ unsigned short data_len)
+{
+ struct ppc4xx_i2c *i2c = (struct ppc4xx_i2c *)I2C_BASE_ADDR;
+ u8 *ptr;
+ int reading;
+ int tran, cnt;
+ int result;
+ int status;
+ int i;
+ u8 creg;
+
+ if (data == 0 || data_len == 0) {
+ /* Don't support data transfer of no length or to address 0 */
+ printf( "i2c_transfer: bad call\n" );
+ return IIC_NOK;
+ }
+ if (addr && addr_len) {
+ ptr = addr;
+ cnt = addr_len;
+ reading = 0;
+ } else {
+ ptr = data;
+ cnt = data_len;
+ reading = cmd_type;
+ }
+
+ /* Clear Stop Complete Bit */
+ out_8(&i2c->sts, IIC_STS_SCMP);
+
+ /* Check init */
+ i = 10;
+ do {
+ /* Get status */
+ status = in_8(&i2c->sts);
+ i--;
+ } while ((status & IIC_STS_PT) && (i > 0));
+
+ if (status & IIC_STS_PT) {
+ result = IIC_NOK_TOUT;
+ return(result);
+ }
+
+ /* flush the Master/Slave Databuffers */
+ out_8(&i2c->mdcntl, in_8(&i2c->mdcntl) |
+ IIC_MDCNTL_FMDB | IIC_MDCNTL_FSDB);
+
+ /* need to wait 4 OPB clocks? code below should take that long */
+
+ /* 7-bit adressing */
+ out_8(&i2c->hmadr, 0);
+ out_8(&i2c->lmadr, chip);
+
+ tran = 0;
+ result = IIC_OK;
+ creg = 0;
+
+ while (tran != cnt && (result == IIC_OK)) {
+ int bc,j;
+
+ /*
+ * Control register =
+ * Normal transfer, 7-bits adressing, Transfer up to
+ * bc bytes, Normal start, Transfer is a sequence of transfers
+ */
+ creg |= IIC_CNTL_PT;
+
+ bc = (cnt - tran) > 4 ? 4 : cnt - tran;
+ creg |= (bc - 1) << 4;
+ /* if the real cmd type is write continue trans */
+ if ((!cmd_type && (ptr == addr)) || ((tran + bc) != cnt))
+ creg |= IIC_CNTL_CHT;
+
+ if (reading) {
+ creg |= IIC_CNTL_READ;
+ } else {
+ for(j = 0; j < bc; j++) {
+ /* Set buffer */
+ out_8(&i2c->mdbuf, ptr[tran + j]);
+ }
+ }
+ out_8(&i2c->cntl, creg);
+
+ /*
+ * Transfer is in progress
+ * we have to wait for upto 5 bytes of data
+ * 1 byte chip address+r/w bit then bc bytes
+ * of data.
+ * udelay(10) is 1 bit time at 100khz
+ * Doubled for slop. 20 is too small.
+ */
+ i = 2 * 5 * 8;
+ do {
+ /* Get status */
+ status = in_8(&i2c->sts);
+ udelay(10);
+ i--;
+ } while ((status & IIC_STS_PT) && !(status & IIC_STS_ERR) &&
+ (i > 0));
+
+ if (status & IIC_STS_ERR) {
+ result = IIC_NOK;
+ status = in_8(&i2c->extsts);
+ /* Lost arbitration? */
+ if (status & IIC_EXTSTS_LA)
+ result = IIC_NOK_LA;
+ /* Incomplete transfer? */
+ if (status & IIC_EXTSTS_ICT)
+ result = IIC_NOK_ICT;
+ /* Transfer aborted? */
+ if (status & IIC_EXTSTS_XFRA)
+ result = IIC_NOK_XFRA;
+ } else if ( status & IIC_STS_PT) {
+ result = IIC_NOK_TOUT;
+ }
+
+ /* Command is reading => get buffer */
+ if ((reading) && (result == IIC_OK)) {
+ /* Are there data in buffer */
+ if (status & IIC_STS_MDBS) {
+ /*
+ * even if we have data we have to wait 4OPB
+ * clocks for it to hit the front of the FIFO,
+ * after that we can just read. We should check
+ * XFCNT here and if the FIFO is full there is
+ * no need to wait.
+ */
+ udelay(1);
+ for (j = 0; j < bc; j++)
+ ptr[tran + j] = in_8(&i2c->mdbuf);
+ } else
+ result = IIC_NOK_DATA;
+ }
+ creg = 0;
+ tran += bc;
+ if (ptr == addr && tran == cnt) {
+ ptr = data;
+ cnt = data_len;
+ tran = 0;
+ reading = cmd_type;
+ if (reading)
+ creg = IIC_CNTL_RPST;
+ }
+ }
+ return result;
+}
+
+int i2c_probe(uchar chip)
+{
+ uchar buf[1];
+
+ buf[0] = 0;
+
+ /*
+ * What is needed is to send the chip address and verify that the
+ * address was <ACK>ed (i.e. there was a chip at that address which
+ * drove the data line low).
+ */
+ return (i2c_transfer(1, chip << 1, 0, 0, buf, 1) != 0);
+}
+
+static int ppc4xx_i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer,
+ int len, int read)
+{
+ uchar xaddr[4];
+ int ret;
+
+ if (alen > 4) {
+ printf("I2C: addr len %d not supported\n", alen);
+ return 1;
+ }
+
+ if (alen > 0) {
+ xaddr[0] = (addr >> 24) & 0xFF;
+ xaddr[1] = (addr >> 16) & 0xFF;
+ xaddr[2] = (addr >> 8) & 0xFF;
+ xaddr[3] = addr & 0xFF;
+ }
+
+
+#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
+ /*
+ * EEPROM chips that implement "address overflow" are ones
+ * like Catalyst 24WC04/08/16 which has 9/10/11 bits of
+ * address and the extra bits end up in the "chip address"
+ * bit slots. This makes a 24WC08 (1Kbyte) chip look like
+ * four 256 byte chips.
+ *
+ * Note that we consider the length of the address field to
+ * still be one byte because the extra address bits are
+ * hidden in the chip address.
+ */
+ if (alen > 0)
+ chip |= ((addr >> (alen * 8)) &
+ CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
+#endif
+ if ((ret = i2c_transfer(read, chip << 1, &xaddr[4 - alen], alen,
+ buffer, len)) != 0) {
+ if (gd->have_console) {
+ printf("I2C %s: failed %d\n",
+ read ? "read" : "write", ret);
+ }
+
+ return 1;
+ }
+
+ return 0;
+}
+
+int i2c_read(uchar chip, uint addr, int alen, uchar * buffer, int len)
+{
+ return ppc4xx_i2c_transfer(chip, addr, alen, buffer, len, 1);
+}
+
+int i2c_write(uchar chip, uint addr, int alen, uchar * buffer, int len)
+{
+ return ppc4xx_i2c_transfer(chip, addr, alen, buffer, len, 0);
+}
+
+#if defined(CONFIG_I2C_MULTI_BUS)
+/*
+ * Functions for multiple I2C bus handling
+ */
+unsigned int i2c_get_bus_num(void)
+{
+ return i2c_bus_num;
+}
+
+int i2c_set_bus_num(unsigned int bus)
+{
+ if (bus >= CONFIG_SYS_MAX_I2C_BUS)
+ return -1;
+
+ i2c_bus_num = bus;
+
+ return 0;
+}
+#endif /* CONFIG_I2C_MULTI_BUS */
+#endif /* CONFIG_HARD_I2C */
generated by cgit v1.1 at 2024-11-24 20:42:49 +0000