8xx i2c refers to unspecified chip errata
Joakim Tjernlund
joakim.tjernlund at lumentis.se
Tue Oct 22 19:15:38 EST 2002
> On Fri, Oct 11, 2002 at 11:12:02AM +0200, Joakim Tjernlund wrote:
>
> > OK, here it is.
> >
> > Perhaps someone can add it to the ppctree?
>
> If you can submit this as a patch vs what's in the i2c CVS tree or the
> ppctree, than yes, this can be committed there, and to the ppctrees.
Here is a patch against the PPC 2.4 devel tree for the i2c-algo-8xx.c
Tom, do you look after 8xx_io/enet.c? I sent a patch to the emmbedded list
yesterday that does away with an expensive memcpy.
Jocke
--- i2c-algo-8xx.c Mon Sep 30 16:20:42 2002
+++ i2c-algo-8xx.c.clean Tue Oct 22 10:49:33 2002
@@ -7,15 +7,12 @@
* Brad Parker (brad at heeltoe.com)
*/
-// XXX todo
-// timeout sleep?
-
/* $Id$ */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
-#include <linux/malloc.h>
+#include <linux/slab.h>
#include <linux/version.h>
#include <linux/init.h>
#include <asm/uaccess.h>
@@ -30,25 +27,25 @@
#include <linux/i2c-algo-8xx.h>
#define CPM_MAX_READ 513
-
+/* #define I2C_CHIP_ERRATA */ /* Try uncomment this if you have an older CPU(earlier than rev D4) */
static wait_queue_head_t iic_wait;
static ushort r_tbase, r_rbase;
int cpm_scan = 0;
-int cpm_debug = 1;
+int cpm_debug = 0;
-static void
-cpm_iic_interrupt(void *dev_id)
+static void
+cpm_iic_interrupt(void *dev_id, struct pt_regs *regs)
{
volatile i2c8xx_t *i2c = (i2c8xx_t *)dev_id;
-
if (cpm_debug > 1)
printk("cpm_iic_interrupt(dev_id=%p)\n", dev_id);
-
- /* Chip errata, clear enable.
- */
- i2c->i2c_i2mod = 0;
-
+#if 0
+ /* Chip errata, clear enable. This is not needed on rev D4 CPUs */
+ /* This should probably be removed and replaced by I2C_CHIP_ERRATA stuff */
+ /* Someone with a buggy CPU needs to confirm that */
+ i2c->i2c_i2mod &= ~1;
+#endif
/* Clear interrupt.
*/
i2c->i2c_i2cer = 0xff;
@@ -63,6 +60,8 @@
{
volatile iic_t *iip = cpm_adap->iip;
volatile i2c8xx_t *i2c = cpm_adap->i2c;
+ unsigned char brg;
+ bd_t *bd = (bd_t *)__res;
if (cpm_debug) printk("cpm_iic_init()\n");
@@ -101,15 +100,24 @@
cp->cp_cpcr =
mk_cr_cmd(CPM_CR_CH_I2C, CPM_CR_INIT_TRX) | CPM_CR_FLG;
while (cp->cp_cpcr & CPM_CR_FLG);
+ } else {
+ iip->iic_rbptr = iip->iic_rbase;
+ iip->iic_tbptr = iip->iic_tbase;
+ iip->iic_rstate = 0;
+ iip->iic_tstate = 0;
}
/* Select an arbitrary address. Just make sure it is unique.
*/
- i2c->i2c_i2add = 0x34;
+ i2c->i2c_i2add = 0xfe;
- /* Make clock run maximum slow.
+ /* Make clock run at 60 KHz.
*/
- i2c->i2c_i2brg = 7;
+ brg = (unsigned char) (bd->bi_intfreq/(32*2*60000) -3);
+ i2c->i2c_i2brg = brg;
+
+ i2c->i2c_i2mod = 0x00;
+ i2c->i2c_i2com = 0x01; /* Master mode */
/* Disable interrupts.
*/
@@ -131,7 +139,7 @@
/* Shut down IIC.
*/
- i2c->i2c_i2mod = 0;
+ i2c->i2c_i2mod &= ~1;
i2c->i2c_i2cmr = 0;
i2c->i2c_i2cer = 0xff;
@@ -151,22 +159,24 @@
iip->iic_rstate = 0;
iip->iic_rdp = 0;
- iip->iic_rbptr = 0;
+ iip->iic_rbptr = iip->iic_rbase;
iip->iic_rbc = 0;
iip->iic_rxtmp = 0;
iip->iic_tstate = 0;
iip->iic_tdp = 0;
- iip->iic_tbptr = 0;
+ iip->iic_tbptr = iip->iic_tbase;
iip->iic_tbc = 0;
iip->iic_txtmp = 0;
}
#define BD_SC_NAK ((ushort)0x0004) /* NAK - did not respond */
+#define BD_SC_OV ((ushort)0x0002) /* OV - receive overrun */
#define CPM_CR_CLOSE_RXBD ((ushort)0x0007)
static void force_close(struct i2c_algo_8xx_data *cpm)
{
- if (cpm->reloc == 0) {
+ volatile i2c8xx_t *i2c = cpm->i2c;
+ if (cpm->reloc == 0) { /* micro code disabled */
volatile cpm8xx_t *cp = cpm->cp;
if (cpm_debug) printk("force_close()\n");
@@ -176,6 +186,8 @@
while (cp->cp_cpcr & CPM_CR_FLG);
}
+ i2c->i2c_i2cmr = 0x00; /* Disable all interrupts */
+ i2c->i2c_i2cer = 0xff;
}
@@ -190,7 +202,7 @@
volatile cpm8xx_t *cp = cpm->cp;
volatile cbd_t *tbdf, *rbdf;
u_char *tb;
- unsigned long flags;
+ unsigned long flags, tmo;
if (count >= CPM_MAX_READ)
return -EINVAL;
@@ -207,68 +219,104 @@
* All that is used is the first byte for address, the remainder
* is just used for timing (and doesn't really have to exist).
*/
- if (cpm->reloc) {
- cpm_reset_iic_params(iip);
- }
tb = cpm->temp;
tb = (u_char *)(((uint)tb + 15) & ~15);
tb[0] = abyte; /* Device address byte w/rw flag */
- flush_dcache_range(tb, tb+1);
-
+ flush_dcache_range((unsigned long)tb, (unsigned long)(tb+1));
if (cpm_debug) printk("cpm_iic_read(abyte=0x%x)\n", abyte);
tbdf->cbd_bufaddr = __pa(tb);
tbdf->cbd_datlen = count + 1;
tbdf->cbd_sc =
- BD_SC_READY | BD_SC_INTRPT | BD_SC_LAST |
+ BD_SC_READY | BD_SC_LAST |
BD_SC_WRAP | BD_IIC_START;
+ iip->iic_mrblr = count +1; /* prevent excessive read, +1
+ is needed otherwise will the
+ RXB interrupt come too early */
+
+ /* flush will invalidate too. */
+ flush_dcache_range((unsigned long)buf, (unsigned long)(buf+count));
+
rbdf->cbd_datlen = 0;
rbdf->cbd_bufaddr = __pa(buf);
- rbdf->cbd_sc = BD_SC_EMPTY | BD_SC_WRAP;
-
- /* Chip bug, set enable here */
- save_flags(flags); cli();
- i2c->i2c_i2cmr = 0x13; /* Enable some interupts */
- i2c->i2c_i2cer = 0xff;
- i2c->i2c_i2mod = 1; /* Enable */
- i2c->i2c_i2com = 0x81; /* Start master */
+ rbdf->cbd_sc = BD_SC_EMPTY | BD_SC_WRAP| BD_SC_INTRPT;
+ if(count > 16){
+ /* Chip bug, set enable here */
+ local_irq_save(flags);
+ i2c->i2c_i2cmr = 0x13; /* Enable some interupts */
+ i2c->i2c_i2cer = 0xff;
+ i2c->i2c_i2mod |= 1; /* Enable */
+ i2c->i2c_i2com |= 0x80; /* Begin transmission */
+
+ /* Wait for IIC transfer */
+ tmo = interruptible_sleep_on_timeout(&iic_wait,1*HZ);
+ local_irq_restore(flags);
+ } else { /* busy wait for small transfers, its faster */
+ i2c->i2c_i2cmr = 0x00; /* Disable I2C interupts */
+ i2c->i2c_i2cer = 0xff;
+ i2c->i2c_i2mod |= 1; /* Enable */
+ i2c->i2c_i2com |= 0x80; /* Begin transmission */
+ tmo = jiffies + 1*HZ;
+ while(!(i2c->i2c_i2cer & 0x11 || time_after(jiffies, tmo))); /* Busy wait, with a timeout */
+ }
- /* Wait for IIC transfer */
- interruptible_sleep_on(&iic_wait);
- restore_flags(flags);
- if (signal_pending(current))
+ if (signal_pending(current) || !tmo){
+ force_close(cpm);
+ if(cpm_debug)
+ printk("IIC read: timeout!\n");
return -EIO;
-
+ }
+#ifdef I2C_CHIP_ERRATA
+ /* Chip errata, clear enable. This is not needed on rev D4 CPUs.
+ Disabling I2C too early may cause too short stop condition */
+ udelay(4);
+ i2c->i2c_i2mod &= ~1;
+#endif
if (cpm_debug) {
printk("tx sc %04x, rx sc %04x\n",
tbdf->cbd_sc, rbdf->cbd_sc);
}
+ if (tbdf->cbd_sc & BD_SC_READY) {
+ printk("IIC read; complete but tbuf ready\n");
+ force_close(cpm);
+ printk("tx sc %04x, rx sc %04x\n",
+ tbdf->cbd_sc, rbdf->cbd_sc);
+ }
+
if (tbdf->cbd_sc & BD_SC_NAK) {
- printk("IIC read; no ack\n");
- return 0;
+ if (cpm_debug)
+ printk("IIC read; no ack\n");
+ return -EREMOTEIO;
}
if (rbdf->cbd_sc & BD_SC_EMPTY) {
- printk("IIC read; complete but rbuf empty\n");
- force_close(cpm);
- printk("tx sc %04x, rx sc %04x\n",
- tbdf->cbd_sc, rbdf->cbd_sc);
+ /* force_close(cpm); */
+ if (cpm_debug){
+ printk("IIC read; complete but rbuf empty\n");
+ printk("tx sc %04x, rx sc %04x\n",
+ tbdf->cbd_sc, rbdf->cbd_sc);
+ }
+ return -EREMOTEIO;
+ }
+
+ if (rbdf->cbd_sc & BD_SC_OV) {
+ if (cpm_debug)
+ printk("IIC read; Overrun\n");
+ return -EREMOTEIO;;
}
if (cpm_debug) printk("read %d bytes\n", rbdf->cbd_datlen);
if (rbdf->cbd_datlen < count) {
- printk("IIC read; short, wanted %d got %d\n",
- count, rbdf->cbd_datlen);
+ if (cpm_debug)
+ printk("IIC read; short, wanted %d got %d\n",
+ count, rbdf->cbd_datlen);
return 0;
}
-
- invalidate_dcache_range(buf, buf+count);
-
return count;
}
@@ -283,7 +331,7 @@
volatile cpm8xx_t *cp = cpm->cp;
volatile cbd_t *tbdf;
u_char *tb;
- unsigned long flags;
+ unsigned long flags, tmo;
/* check for and use a microcode relocation patch */
if (cpm->reloc) {
@@ -293,8 +341,8 @@
tb = (u_char *)(((uint)tb + 15) & ~15);
*tb = abyte; /* Device address byte w/rw flag */
- flush_dcache_range(tb, tb+1);
- flush_dcache_range(buf, buf+count);
+ flush_dcache_range((unsigned long)tb, (unsigned long)(tb+1));
+ flush_dcache_range((unsigned long)buf, (unsigned long)(buf+count));
if (cpm_debug) printk("cpm_iic_write(abyte=0x%x)\n", abyte);
@@ -309,31 +357,53 @@
tbdf[1].cbd_datlen = count;
tbdf[1].cbd_sc = BD_SC_READY | BD_SC_INTRPT | BD_SC_LAST | BD_SC_WRAP;
- /* Chip bug, set enable here */
- save_flags(flags); cli();
- i2c->i2c_i2cmr = 0x13; /* Enable some interupts */
- i2c->i2c_i2cer = 0xff;
- i2c->i2c_i2mod = 1; /* Enable */
- i2c->i2c_i2com = 0x81; /* Start master */
+ if(count > 16){
+ /* Chip bug, set enable here */
+ local_irq_save(flags);
+ i2c->i2c_i2cmr = 0x13; /* Enable some interupts */
+ i2c->i2c_i2cer = 0xff;
+ i2c->i2c_i2mod |= 1; /* Enable */
+ i2c->i2c_i2com |= 0x80; /* Begin transmission */
+
+ /* Wait for IIC transfer */
+ tmo = interruptible_sleep_on_timeout(&iic_wait,1*HZ);
+ local_irq_restore(flags);
+ } else { /* busy wait for small transfers, its faster */
+ i2c->i2c_i2cmr = 0x00; /* Disable I2C interupts */
+ i2c->i2c_i2cer = 0xff;
+ i2c->i2c_i2mod |= 1; /* Enable */
+ i2c->i2c_i2com |= 0x80; /* Begin transmission */
+ tmo = jiffies + 1*HZ;
+ while(!(i2c->i2c_i2cer & 0x12 || time_after(jiffies, tmo))); /* Busy wait, with a timeout */
+ }
- /* Wait for IIC transfer */
- interruptible_sleep_on(&iic_wait);
- restore_flags(flags);
- if (signal_pending(current))
+ if (signal_pending(current) || !tmo){
+ force_close(cpm);
+ if(cpm_debug && !tmo)
+ printk("IIC write: timeout!\n");
return -EIO;
-
+ }
+
+#if I2C_CHIP_ERRATA
+ /* Chip errata, clear enable. This is not needed on rev D4 CPUs.
+ Disabling I2C too early may cause too short stop condition */
+ udelay(4);
+ i2c->i2c_i2mod &= ~1;
+#endif
if (cpm_debug) {
printk("tx0 sc %04x, tx1 sc %04x\n",
tbdf[0].cbd_sc, tbdf[1].cbd_sc);
}
if (tbdf->cbd_sc & BD_SC_NAK) {
- printk("IIC write; no ack\n");
+ if (cpm_debug)
+ printk("IIC write; no ack\n");
return 0;
}
if (tbdf->cbd_sc & BD_SC_READY) {
- printk("IIC write; complete but tbuf ready\n");
+ if (cpm_debug)
+ printk("IIC write; complete but tbuf ready\n");
return 0;
}
@@ -351,7 +421,7 @@
volatile cpm8xx_t *cp = cpm->cp;
volatile cbd_t *tbdf, *rbdf;
u_char *tb;
- unsigned long flags, len;
+ unsigned long flags, len, tmo;
if (cpm_debug > 1)
printk("cpm_iic_tryaddress(cpm=%p,addr=%d)\n", cpm, addr);
@@ -376,31 +446,43 @@
tb[0] = (addr << 1) | 1; /* device address (+ read) */
len = 2;
- flush_dcache_range(tb, tb+1);
+ flush_dcache_range((unsigned long)tb, (unsigned long)(tb+2));
tbdf->cbd_bufaddr = __pa(tb);
tbdf->cbd_datlen = len;
tbdf->cbd_sc =
- BD_SC_READY | BD_SC_INTRPT | BD_SC_LAST |
+ BD_SC_READY | BD_SC_LAST |
BD_SC_WRAP | BD_IIC_START;
rbdf->cbd_datlen = 0;
rbdf->cbd_bufaddr = __pa(tb+2);
- rbdf->cbd_sc = BD_SC_EMPTY | BD_SC_WRAP;
+ rbdf->cbd_sc = BD_SC_EMPTY | BD_SC_WRAP | BD_SC_INTRPT;
- save_flags(flags); cli();
+ local_irq_save(flags);
i2c->i2c_i2cmr = 0x13; /* Enable some interupts */
i2c->i2c_i2cer = 0xff;
- i2c->i2c_i2mod = 1; /* Enable */
- i2c->i2c_i2com = 0x81; /* Start master */
+ i2c->i2c_i2mod |= 1; /* Enable */
+ i2c->i2c_i2com |= 0x80; /* Begin transmission */
if (cpm_debug > 1) printk("about to sleep\n");
/* wait for IIC transfer */
- interruptible_sleep_on(&iic_wait);
- restore_flags(flags);
- if (signal_pending(current))
+ tmo = interruptible_sleep_on_timeout(&iic_wait,1*HZ);
+ local_irq_restore(flags);
+
+#ifdef I2C_CHIP_ERRATA
+ /* Chip errata, clear enable. This is not needed on rev D4 CPUs.
+ Disabling I2C too early may cause too short stop condition */
+ udelay(4);
+ i2c->i2c_i2mod &= ~1;
+#endif
+
+ if (signal_pending(current) || !tmo){
+ force_close(cpm);
+ if(cpm_debug && !tmo)
+ printk("IIC tryaddress: timeout!\n");
return -EIO;
+ }
if (cpm_debug > 1) printk("back from sleep\n");
@@ -430,8 +512,8 @@
if (cpm_debug)
printk("i2c-algo-8xx.o: "
- "#%d addr=0x%x flags=0x%x len=%d\n",
- i, pmsg->addr, pmsg->flags, pmsg->len);
+ "#%d addr=0x%x flags=0x%x len=%d\n buf=%lx\n",
+ i, pmsg->addr, pmsg->flags, pmsg->len, (unsigned long)pmsg->buf);
addr = pmsg->addr << 1;
if (pmsg->flags & I2C_M_RD )
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