On Mon, 9 Feb 2009, Heiko Schocher wrote:
Hello ksi,
ksi@koi8.net wrote:
Signed-off-by: Sergey Kubushyn ksi@koi8.net
diff --git a/drivers/i2c/soft_i2c.c b/drivers/i2c/soft_i2c.c index da6cec1..f0c1771 100644 --- a/drivers/i2c/soft_i2c.c +++ b/drivers/i2c/soft_i2c.c @@ -1,4 +1,8 @@ /*
- Copyright (c) 2009 Sergey Kubushyn ksi@koi8.net
- Changes for multibus/multiadapter I2C support.
- (C) Copyright 2001, 2002
- Wolfgang Denk, DENX Software Engineering, wd@denx.de.
@@ -72,375 +76,493 @@ DECLARE_GLOBAL_DATA_PTR; #define PRINTD(fmt,args...) #endif
-#if defined(CONFIG_I2C_MULTI_BUS) -static unsigned int i2c_bus_num __attribute__ ((section (".data"))) = 0; -#endif /* CONFIG_I2C_MULTI_BUS */
/*-----------------------------------------------------------------------
- Local functions
*/ -#if !defined(CONFIG_SYS_I2C_INIT_BOARD) -static void send_reset (void); +#ifndef I2C_INIT +#define I2C_INIT do {} while(0) #endif -static void send_start (void); -static void send_stop (void); -static void send_ack (int); -static int write_byte (uchar byte); -static uchar read_byte (int);
-#if !defined(CONFIG_SYS_I2C_INIT_BOARD) -/*-----------------------------------------------------------------------
- Send a reset sequence consisting of 9 clocks with the data signal high
- to clock any confused device back into an idle state. Also send a
- <stop> at the end of the sequence for belts & suspenders.
- */
-static void send_reset(void) -{
- I2C_SOFT_DECLARATIONS /* intentional without ';' */
- int j;
- I2C_SCL(1);
- I2C_SDA(1);
-#ifdef I2C_INIT
- I2C_INIT;
+#ifndef I2C_INIT0 +#define I2C_INIT0 do {} while(0) #endif
- I2C_TRISTATE;
- for(j = 0; j < 9; j++) {
I2C_SCL(0);I2C_DELAY;I2C_DELAY;I2C_SCL(1);I2C_DELAY;I2C_DELAY;- }
- send_stop();
- I2C_TRISTATE;
-} +#ifndef I2C_INIT1 +#define I2C_INIT1 do {} while(0) +#endif +#ifndef I2C_INIT2 +#define I2C_INIT2 do {} while(0) #endif +#ifndef I2C_INIT3 +#define I2C_INIT3 do {} while(0) +#endif
/*-----------------------------------------------------------------------
- START: High -> Low on SDA while SCL is High
*/ -static void send_start(void) -{
- I2C_SOFT_DECLARATIONS /* intentional without ';' */
- I2C_DELAY;
- I2C_SDA(1);
- I2C_ACTIVE;
- I2C_DELAY;
- I2C_SCL(1);
- I2C_DELAY;
- I2C_SDA(0);
- I2C_DELAY;
+#define I2C_SOFT_SEND_START(n) \ +static void send_start##n(void) \ +{ \
- I2C_SOFT_DECLARATIONS##n \
- I2C_DELAY##n; \
- I2C_SDA##n(1); \
- I2C_ACTIVE##n; \
- I2C_DELAY##n; \
- I2C_SCL##n(1); \
- I2C_DELAY##n; \
- I2C_SDA##n(0); \
- I2C_DELAY##n; \
}
[...]
- PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n",
chip, addr);-#endif +#define DO_EEAD_OVF chip |= ((addr >> (alen * 8)) & CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW); \
Line too long.
No problems, fixed.
PRINTD("%s: fix addr_overflow: chip %02X addr %02X\n", \__FUNCTION__, chip, addr);
- /*
* Do the addressing portion of a write cycle to set the* chip's address pointer. If the address length is zero,* don't do the normal write cycle to set the address pointer,* there is no address pointer in this chip.[...]
+#if defined(I2C_SOFT_DECLARATIONS3) +I2C_SOFT_SEND_START(3) +I2C_SOFT_SEND_STOP(3) +I2C_SOFT_SEND_ACK(3) +#if !defined(CONFIG_SYS_I2C_INIT_BOARD) +I2C_SOFT_SEND_RESET(3) +#endif +I2C_SOFT_WRITE_BYTE(3) +I2C_SOFT_READ_BYTE(3) +I2C_SOFT_INIT_ADAPTER(3) +I2C_SOFT_PROBE(3) +I2C_SOFT_READ(3) +I2C_SOFT_WRITE(3) +I2C_SOFT_GET_BUS_SPEED(3) +I2C_SOFT_SET_BUS_SPEED(3) +#endif
Hmm... are this lots of defines really necessary? Couldn't we add something like
int hw_adapnr; /* hardware adapter number */
to the i2c_adap_t struct, and have an pointer (cur_i2c_adap?) to the current used i2c_adap_t? Then you have where you need it, your hw_adapnr and need not all of this defines.
For example you need in the config for MPC8548CDS.h just this define:
#define I2C_SDA(bit) (printf("HW adap: %d sda: %d", cur_i2c_adap->hw_adapnr, bit))
and not I2C_SDA(bit) and I2C_SDA1(bit)
Eh, those are _NOT_ defines, those are _INSTANCES_.
First of all, you need real functions to make pointers to them at compile time.
Second, SOFT_I2C is special; it is _NOT_ possible to make generic paratemerized functions. Each, e.g., I2C_SDA is different and those config file defines are _MACROS_, not defines. One can have one I2C_SOFT adapter made of a couple of on-SoC GPIOs and another one constructed of, e.g., unused GPIOs from PCI bridge or whatever. That means that _ALL_ those I2C_* macros will be totally different for those 2 adapters thus making 2 sets of access functions that have absolutely nothing in common. You can not parameterize this...
I agree that those 4 #ifdef'ed instances are not the prettiest and 4 is an arbitrary number but I'm not THAT good in CPP trickery to come up with a generic template that would be good for arbitrary number of instances if it can be done at all...
And that template allows for using existing SOFT_I2C macros in existing config files without any changes to them.
Also let's not forget that all those function sets are instantiated at _COMPILE_ time so they can be run from ROM.
I would like to hear suggestions on that from real CPP gurus. That would've made the code prettier and I would've learned new neat tricks...
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