| Message ID | 20090331125451.600446749@denx.de (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Kumar Gala |
| Headers | show |
On Tue, Mar 31, 2009 at 02:50:29PM +0200, Wolfgang Grandegger wrote: > The I2c node property "fsl,preserve-clocking" allows to overtake the > clock settings from the boot loader and avoids the hard-coded setting. > > Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> > --- > drivers/i2c/busses/i2c-mpc.c | 24 ++++++++++++++++-------- > 1 file changed, 16 insertions(+), 8 deletions(-) > > Index: linux-2.6/drivers/i2c/busses/i2c-mpc.c > =================================================================== > --- linux-2.6.orig/drivers/i2c/busses/i2c-mpc.c 2009-03-31 13:25:08.000000000 +0200 > +++ linux-2.6/drivers/i2c/busses/i2c-mpc.c 2009-03-31 13:28:03.000000000 +0200 > @@ -318,17 +318,24 @@ > { > int result = 0; > struct mpc_i2c *i2c; > + int set_clock; > > i2c = kzalloc(sizeof(*i2c), GFP_KERNEL); > if (!i2c) > return -ENOMEM; > > - if (of_get_property(op->node, "dfsrr", NULL)) > - i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; > - > - if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || > - of_device_is_compatible(op->node, "mpc5200-i2c")) > - i2c->flags |= FSL_I2C_DEV_CLOCK_5200; > + if (of_get_property(op->node, "fsl,preserve-clocking", NULL)) { > + set_clock = 0; > + } else { > + set_clock = 1; > + > + if (of_get_property(op->node, "dfsrr", NULL)) > + i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; > + > + if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || > + of_device_is_compatible(op->node, "mpc5200-i2c")) > + i2c->flags |= FSL_I2C_DEV_CLOCK_5200; > + } > > init_waitqueue_head(&i2c->queue); > > @@ -348,8 +355,9 @@ > goto fail_request; > } > } > - > - mpc_i2c_setclock(i2c); > + > + if (set_clock) > + mpc_i2c_setclock(i2c); Can't we drop 'set_clock' with something like this here? + if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) { + + if (of_get_property(op->node, "dfsrr", NULL)) + i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; + + if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || + of_device_is_compatible(op->node, "mpc5200-i2c")) + i2c->flags |= FSL_I2C_DEV_CLOCK_5200; + + mpc_i2c_setclock(i2c); + } > > dev_set_drvdata(&op->dev, i2c); > > > _______________________________________________ > devicetree-discuss mailing list > devicetree-discuss@ozlabs.org > https://ozlabs.org/mailman/listinfo/devicetree-discuss Regards, Wolfram
Wolfram Sang wrote: > On Tue, Mar 31, 2009 at 02:50:29PM +0200, Wolfgang Grandegger wrote: >> The I2c node property "fsl,preserve-clocking" allows to overtake the >> clock settings from the boot loader and avoids the hard-coded setting. >> >> Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> >> --- >> drivers/i2c/busses/i2c-mpc.c | 24 ++++++++++++++++-------- >> 1 file changed, 16 insertions(+), 8 deletions(-) >> >> Index: linux-2.6/drivers/i2c/busses/i2c-mpc.c >> =================================================================== >> --- linux-2.6.orig/drivers/i2c/busses/i2c-mpc.c 2009-03-31 13:25:08.000000000 +0200 >> +++ linux-2.6/drivers/i2c/busses/i2c-mpc.c 2009-03-31 13:28:03.000000000 +0200 >> @@ -318,17 +318,24 @@ >> { >> int result = 0; >> struct mpc_i2c *i2c; >> + int set_clock; >> >> i2c = kzalloc(sizeof(*i2c), GFP_KERNEL); >> if (!i2c) >> return -ENOMEM; >> >> - if (of_get_property(op->node, "dfsrr", NULL)) >> - i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; >> - >> - if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || >> - of_device_is_compatible(op->node, "mpc5200-i2c")) >> - i2c->flags |= FSL_I2C_DEV_CLOCK_5200; >> + if (of_get_property(op->node, "fsl,preserve-clocking", NULL)) { >> + set_clock = 0; >> + } else { >> + set_clock = 1; >> + >> + if (of_get_property(op->node, "dfsrr", NULL)) >> + i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; >> + >> + if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || >> + of_device_is_compatible(op->node, "mpc5200-i2c")) >> + i2c->flags |= FSL_I2C_DEV_CLOCK_5200; >> + } >> >> init_waitqueue_head(&i2c->queue); >> >> @@ -348,8 +355,9 @@ >> goto fail_request; >> } >> } >> - >> - mpc_i2c_setclock(i2c); >> + >> + if (set_clock) >> + mpc_i2c_setclock(i2c); > > Can't we drop 'set_clock' with something like this here? > > + if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) { > + > + if (of_get_property(op->node, "dfsrr", NULL)) > + i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; > + > + if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || > + of_device_is_compatible(op->node, "mpc5200-i2c")) > + i2c->flags |= FSL_I2C_DEV_CLOCK_5200; > + > + mpc_i2c_setclock(i2c); > + } No, because the I2C registers are not yet mapped. Wolfgang.
> >> - > >> - mpc_i2c_setclock(i2c); > >> + > >> + if (set_clock) > >> + mpc_i2c_setclock(i2c); > > > > Can't we drop 'set_clock' with something like this here? > > > > + if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) { > > + > > + if (of_get_property(op->node, "dfsrr", NULL)) > > + i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; > > + > > + if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || > > + of_device_is_compatible(op->node, "mpc5200-i2c")) > > + i2c->flags |= FSL_I2C_DEV_CLOCK_5200; > > + > > + mpc_i2c_setclock(i2c); > > + } > > No, because the I2C registers are not yet mapped. Sorry, I used misleading words :) With 'here' I meant 'at this position', i.e. insert my above block where mpc_i2c_setclock was used anyway.
2009/3/31 Wolfram Sang <w.sang@pengutronix.de>: > >> >> - >> >> - mpc_i2c_setclock(i2c); >> >> + >> >> + if (set_clock) >> >> + mpc_i2c_setclock(i2c); >> > >> > Can't we drop 'set_clock' with something like this here? >> > >> > + if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) { >> > + >> > + if (of_get_property(op->node, "dfsrr", NULL)) >> > + i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; >> > + >> > + if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || >> > + of_device_is_compatible(op->node, "mpc5200-i2c")) >> > + i2c->flags |= FSL_I2C_DEV_CLOCK_5200; >> > + >> > + mpc_i2c_setclock(i2c); >> > + } >> >> No, because the I2C registers are not yet mapped. > > Sorry, I used misleading words :) With 'here' I meant 'at this > position', i.e. insert my above block where mpc_i2c_setclock was used > anyway. I agree. The extra flag makes the flow more complex. The code block should be moved down. g.
Grant Likely wrote: > 2009/3/31 Wolfram Sang <w.sang@pengutronix.de>: >>>>> - >>>>> - mpc_i2c_setclock(i2c); >>>>> + >>>>> + if (set_clock) >>>>> + mpc_i2c_setclock(i2c); >>>> Can't we drop 'set_clock' with something like this here? >>>> >>>> + if (!of_get_property(op->node, "fsl,preserve-clocking", NULL)) { >>>> + >>>> + if (of_get_property(op->node, "dfsrr", NULL)) >>>> + i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; >>>> + >>>> + if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || >>>> + of_device_is_compatible(op->node, "mpc5200-i2c")) >>>> + i2c->flags |= FSL_I2C_DEV_CLOCK_5200; >>>> + >>>> + mpc_i2c_setclock(i2c); >>>> + } >>> No, because the I2C registers are not yet mapped. >> Sorry, I used misleading words :) With 'here' I meant 'at this >> position', i.e. insert my above block where mpc_i2c_setclock was used >> anyway. > > I agree. The extra flag makes the flow more complex. The code block > should be moved down. OK, I just resent the patch standalone also including documentation. I think it can go in immediately without waiting for the full clock setting patch. Wolfgang.
Does anyone know if the I2C temperature sensor is functioning on the AMCC 460EX? When I do a cat /proc/ad7416 I get the following crash. Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc02cbe28 Oops: Kernel access of bad area, sig: 11 [#1] PowerPC 44x Platform NIP: c02cbe28 LR: c023cec8 CTR: c023d314 REGS: ef107d90 TRAP: 0300 Not tainted (2.6.28.7) MSR: 00029000 <EE,ME> CR: 88000444 XER: 00000000 DEAR: 00000000, ESR: 00000000 TASK = ef8590c0[2611] 'cat' THREAD: ef106000 GPR00: 00000000 ef107e40 ef8590c0 00000000 ef107e9c 00000000 00000c00 ef107e98 GPR08: 00000000 c0330000 ffffffff c0330000 48000448 1001cb7c 100042bc 100df49c GPR16: 00000002 00000400 c032f014 c032efe4 ef107e9c ef107e98 bfffffff efb43a00 GPR24: ef61d000 00000000 ef107f20 ef107e98 00000c00 c0400000 00001000 efb43a00 NIP [c02cbe28] mutex_lock+0x0/0x1c LR [c023cec8] ad7416_read_temp+0x24/0x80 Call Trace: [ef107e40] [00000400] 0x400 (unreliable) [ef107e70] [c023d334] i2c_ad7416_read_proc+0x20/0x70 [ef107e90] [c00e8018] proc_file_read+0x108/0x334 [ef107ee0] [c00e2d3c] proc_reg_read+0x4c/0x70 [ef107ef0] [c00a54e8] vfs_read+0xb4/0x16c [ef107f10] [c00a58e0] sys_read+0x4c/0x90 [ef107f40] [c000ea88] ret_from_syscall+0x0/0x3c Instruction dump: 90010014 38000001 90030000 85230004 7f891800 419e000c 80690008 4bd50779 80010014 38210010 7c0803a6 4e800020 <7c001828> 3000ffff 7c00192d 40a2fff4 ---[ end trace 774db769c3754abe ]--- ********************************************************** Outbound scan for Spam or Virus by Barracuda at Delta Tau **********************************************************
Did you have dts entries for IIC in device tree ? also did you have I2C enabled in "make menuconfig"
"device drivers -> i2c support --> I2C bus support -> IBM ppc 4xx On chip I2C support " selected. Then you should i2c see an entry /proc/devices . Use that major address and create a device node "mknode /dev/i2c-0 c 89 0" .
Write a user level program to access this device. Here is an example user code.
----------
cat fan.c
/* This program is an example of writing and reading an EEPROM device via
SMBus on a GE Fanuc Embedded Systems, Inc. VMIVME-7809 Single Board
Computer.
To compile this program:
gcc -O vmieep.c -o vmieep
Before running this program, log in as root, then load the following
modules using:
/sbin/modprobe i2c-core
/sbin/modprobe i2c-dev
/sbin/modprobe i2c-i801
Loading the i2c-i801 module will create /dev/i2c-0, with
permissions = CRW- --- ---. Either run the vmieep program as root,
or change the permissions to CRW- RW- RW- as shown:
chmod 666 /dev/i2c-0
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
//#include <linux/i2c.h>
//#include <linux/i2c-dev.h>
#include <sys/time.h>
/* The inline smbus function definitions may or may not be in i2c-dev.h,
depending on the Linux distribution. Comment or uncomment the following
#include as necessary. */
#include "i2c-dev.h" /* Use the file of lm_sensors */
#define EEPROM_SIZE 256 /* Adjust for actual number of bytes in EEPROM */
#define EEPROM_SMBUS_ADDR 0x90 /* Do NOT change! */
int gef_eeprom_read(int fd, unsigned char start_offset, unsigned char *buffer,
unsigned short buflen);
int gef_eeprom_write(int fd, unsigned char start_offset, unsigned char *buffer,
unsigned short buflen);
void gef_msec_delay(unsigned int msecs);
int main(int argc, char *argv[])
{
int fd; /* File descriptor initialized with open() */
int adapter_num = 0;
int status;
char filename[20]; /* Name of special device file */
int i2c_addr = EEPROM_SMBUS_ADDR; /* SMBus address of EEPROM */
unsigned short offset; /* Which byte to access in the EEPROM */
unsigned char rbuffer; /* Data read from EEPROM */
if ((argc < 3) || (argc > 4))
{
printf("Usage: fan read <addr> or fan write <addr> <data>\n");
return 0;
}
/* Open the special device file for the SMBus */
sprintf(filename, "/dev/i2c-%d", adapter_num);
fd = open(filename, O_RDWR);
if (fd < 0)
{
printf("ERROR: open(%s) failed\n", filename);
printf("errno = %d, %s\n", errno, strerror(errno));
return -1;
}
//printf("SUCCESS: open(%s) passed\n", filename);
/* Specify the EEPROM as the device we want to access.
*** IMPORTANT ***
The address is actually in the 7 LSBs, so shift
i2c_addr one bit to the right.*/
status = ioctl(fd, I2C_SLAVE, i2c_addr>>1);
if (status < 0)
{
printf("ERROR: ioctl(fd, I2C_SLAVE, 0x%02X) failed\n", i2c_addr);
printf("errno = %d, %s\n", errno, strerror(errno));
close(fd);
return -1;
}
//printf("SUCCESS: ioctl(fd, I2C_SLAVE, 0x%02X>>1) passed\n", i2c_addr);
if (strcmp(argv[1],"read") == 0)
{
offset = atoi(argv[2]);
gef_eeprom_read(fd, offset, &rbuffer, 1);
printf("Offset: %d Data: %d\n", offset, rbuffer);
}
if (strcmp(argv[1],"write") == 0)
{
offset = (unsigned char)(atoi(argv[2]));
rbuffer =(unsigned char)(atoi(argv[3]));
gef_eeprom_write(fd, offset, &rbuffer, 1);
printf("Offset: %d Data: %d\n", offset, rbuffer);
}
/* Close the special device file */
close(fd);
return 0;
}
//////////////////////////////////////////////////////////////////////////////
//
// Function name : gef_eeprom_read
//
// Description : Read buflen bytes from the EEPROM beginning at start_offset
//
// Return type : 0 for success, -1 for failure
//
// Argument : int fd : File descriptor returned by open()
// Argument : unsigned char start_offset : Read bytes starting at this
// offset in the EEPROM. The sum of buflen and
// start_offset must not exceed the maximum size in bytes
// of the EEPROM
// Argument : unsigned char *buffer : Where to store the bytes read
// from the EEPROM. The buffer must be large enough
// to store buflen bytes read from the EEPROM.
// Argument : unsigned short buflen : The size in bytes of buffer, or
// how many bytes to read from the EEPROM. The sum of
// buflen and start_offset must not exceed the maximum
// size in bytes of the EEPROM.
//
int gef_eeprom_read(int fd, unsigned char start_offset, unsigned char *buffer,
unsigned short buflen)
{
int offset, index;
int data;
for (index=0, offset=start_offset; index<buflen &&
offset<EEPROM_SIZE; index++, offset++)
{
data = i2c_smbus_read_byte_data(fd, offset);
if (data == -1)
{
printf("ERROR: i2c_smbus_read_byte_data(fd, 0x%02X) failed\n",
offset);
printf("errno = %d, %s\n", errno, strerror(errno));
return -1;
}
buffer[index] = (unsigned char) (data);
}
return 0;
}
//////////////////////////////////////////////////////////////////////////////
//
// Function name : gef_eeprom_write
//
// Description : Write buflen bytes to the EEPROM beginning at start_offset
//
// Return type : 0 for success, -1 for failure
//
// Argument : int fd : File descriptor returned by open()
// Argument : unsigned char start_offset : Write bytes starting at this
// offset in the EEPROM. The sum of buflen and
// start_offset must not exceed the maximum size in bytes
// of the EEPROM
// Argument : unsigned char *buffer : Where to get the bytes to write
// to the EEPROM.
// Argument : unsigned short buflen : The size in bytes of buffer.
// The sum of buflen and start_offset must not exceed the
// maximum size in bytes of the EEPROM.
//
int gef_eeprom_write(int fd, unsigned char start_offset, unsigned char *buffer,
unsigned short buflen)
{
int offset, index;
int status;
for (index=0, offset=start_offset; index<buflen &&
offset<EEPROM_SIZE; index++, offset++)
{
status = i2c_smbus_write_byte_data(fd, offset, buffer[index]);
if (status < 0)
{
printf("ERROR: i2c_smbus_write_byte_data(fd, 0x%02X, 0x%02X) failed\n",
offset, buffer[index]);
printf("errno = %d, %s\n", errno, strerror(errno));
return -1;
}
/* Delay while the byte write completes */
gef_msec_delay(10);
}
return 0;
}
//////////////////////////////////////////////////////////////////////////////
//
// Function name : gef_msec_delay
//
// Description : Delay for a number of milliseconds before returning
//
// Return type : void
//
// Argument : unsigned int msecs : The number of milliseconds to delay
//
void gef_msec_delay(unsigned int msecs)
{
struct timeval s_current, s_start;
struct timezone tz;
unsigned int current, start;
/* Get initial time */
gettimeofday(&s_start, &tz);
start = s_start.tv_sec*1000000 + s_start.tv_usec;
/* Loop until msecs time have elapsed */
do
{
gettimeofday(&s_current, &tz);
current = s_current.tv_sec*1000000 + s_current.tv_usec;
} while ((current-start) < (msecs*1000));
}
-------------
Index: linux-2.6/drivers/i2c/busses/i2c-mpc.c =================================================================== --- linux-2.6.orig/drivers/i2c/busses/i2c-mpc.c 2009-03-31 13:25:08.000000000 +0200 +++ linux-2.6/drivers/i2c/busses/i2c-mpc.c 2009-03-31 13:28:03.000000000 +0200 @@ -318,17 +318,24 @@ { int result = 0; struct mpc_i2c *i2c; + int set_clock; i2c = kzalloc(sizeof(*i2c), GFP_KERNEL); if (!i2c) return -ENOMEM; - if (of_get_property(op->node, "dfsrr", NULL)) - i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; - - if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || - of_device_is_compatible(op->node, "mpc5200-i2c")) - i2c->flags |= FSL_I2C_DEV_CLOCK_5200; + if (of_get_property(op->node, "fsl,preserve-clocking", NULL)) { + set_clock = 0; + } else { + set_clock = 1; + + if (of_get_property(op->node, "dfsrr", NULL)) + i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR; + + if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") || + of_device_is_compatible(op->node, "mpc5200-i2c")) + i2c->flags |= FSL_I2C_DEV_CLOCK_5200; + } init_waitqueue_head(&i2c->queue); @@ -348,8 +355,9 @@ goto fail_request; } } - - mpc_i2c_setclock(i2c); + + if (set_clock) + mpc_i2c_setclock(i2c); dev_set_drvdata(&op->dev, i2c);
The I2c node property "fsl,preserve-clocking" allows to overtake the clock settings from the boot loader and avoids the hard-coded setting. Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> --- drivers/i2c/busses/i2c-mpc.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-)