Have all programmer init functions register bus masters/programmers

All programmer types (Parallel, SPI, Opaque) now register themselves
into a generic programmer list and probing is now programmer-centric
instead of chip-centric.
Registering multiple SPI/... masters at the same time is now possible
without any problems. Handling multiple flash chips is still unchanged,
but now we have the infrastructure to deal with "dual BIOS" and "one
flash behind southbridge and one flash behind EC" sanely.

A nice side effect is that this patch kills quite a few global variables
and improves the situation for libflashrom.

Hint for developers:
struct {spi,par,opaque}_programmer now have a void *data pointer to
store any additional programmer-specific data, e.g. hardware
configuration info.

Note:
flashrom -f -c FOO -r forced_read.bin
does not work anymore. We have to find an architecturally clean way to
solve this.

Corresponding to flashrom svn r1475.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Michael Karcher <flashrom@mkarcher.dialup.fu-berlin.de>

1 files changed, 56 insertions, 68 deletions

diff --git a/bitbang_spi.c b/bitbang_spi.c
index 5ee52f5..51fc9c6 100644
--- a/bitbang_spi.c
+++ b/bitbang_spi.c
@@ -25,42 +25,37 @@
 #include "programmer.h"
 #include "spi.h"
 
-/* Length of half a clock period in usecs. */
-static int bitbang_spi_half_period;
-
-static const struct bitbang_spi_master *bitbang_spi_master = NULL;
-
 /* Note that CS# is active low, so val=0 means the chip is active. */
-static void bitbang_spi_set_cs(int val)
+static void bitbang_spi_set_cs(const const struct bitbang_spi_master *master, int val)
 {
-	bitbang_spi_master->set_cs(val);
+	master->set_cs(val);
 }
 
-static void bitbang_spi_set_sck(int val)
+static void bitbang_spi_set_sck(const const struct bitbang_spi_master *master, int val)
 {
-	bitbang_spi_master->set_sck(val);
+	master->set_sck(val);
 }
 
-static void bitbang_spi_set_mosi(int val)
+static void bitbang_spi_set_mosi(const const struct bitbang_spi_master *master, int val)
 {
-	bitbang_spi_master->set_mosi(val);
+	master->set_mosi(val);
 }
 
-static int bitbang_spi_get_miso(void)
+static int bitbang_spi_get_miso(const const struct bitbang_spi_master *master)
 {
-	return bitbang_spi_master->get_miso();
+	return master->get_miso();
 }
 
-static void bitbang_spi_request_bus(void)
+static void bitbang_spi_request_bus(const const struct bitbang_spi_master *master)
 {
-	if (bitbang_spi_master->request_bus)
-		bitbang_spi_master->request_bus();
+	if (master->request_bus)
+		master->request_bus();
 }
 
-static void bitbang_spi_release_bus(void)
+static void bitbang_spi_release_bus(const const struct bitbang_spi_master *master)
 {
-	if (bitbang_spi_master->release_bus)
-		bitbang_spi_master->release_bus();
+	if (master->release_bus)
+		master->release_bus();
 }
 
 static int bitbang_spi_send_command(struct flashctx *flash,
@@ -78,67 +73,59 @@ static const struct spi_programmer spi_programmer_bitbang = {
 	.write_256	= default_spi_write_256,
 };
 
-int bitbang_spi_init(const struct bitbang_spi_master *master, int halfperiod)
+#if 0 // until it is needed
+static int bitbang_spi_shutdown(const struct bitbang_spi_master *master)
 {
+	/* FIXME: Run bitbang_spi_release_bus here or per command? */
+	return 0;
+}
+#endif
+
+int bitbang_spi_init(const struct bitbang_spi_master *master)
+{
+	struct spi_programmer pgm = spi_programmer_bitbang;
 	/* BITBANG_SPI_INVALID is 0, so if someone forgot to initialize ->type,
 	 * we catch it here. Same goes for missing initialization of bitbanging
 	 * functions.
 	 */
 	if (!master || master->type == BITBANG_SPI_INVALID || !master->set_cs ||
-	    !master->set_sck || !master->set_mosi || !master->get_miso) {
+	    !master->set_sck || !master->set_mosi || !master->get_miso ||
+	    (master->request_bus && !master->release_bus) ||
+	    (!master->request_bus && master->release_bus)) {
 		msg_perr("Incomplete SPI bitbang master setting!\n"
 			 "Please report a bug at flashrom@flashrom.org\n");
-		return 1;
-	}
-	if (bitbang_spi_master) {
-		msg_perr("SPI bitbang master already initialized!\n"
-			 "Please report a bug at flashrom@flashrom.org\n");
-		return 1;
+		return ERROR_FLASHROM_BUG;
 	}
 
-	bitbang_spi_master = master;
-	bitbang_spi_half_period = halfperiod;
+	pgm.data = master;
+	register_spi_programmer(&pgm);
 
-	register_spi_programmer(&spi_programmer_bitbang);
-
-	/* FIXME: Run bitbang_spi_request_bus here or in programmer init? */
-	bitbang_spi_set_cs(1);
-	bitbang_spi_set_sck(0);
-	bitbang_spi_set_mosi(0);
-	return 0;
-}
-
-int bitbang_spi_shutdown(const struct bitbang_spi_master *master)
-{
-	if (!bitbang_spi_master) {
-		msg_perr("Shutting down an uninitialized SPI bitbang master!\n"
-			 "Please report a bug at flashrom@flashrom.org\n");
-		return 1;
-	}
-	if (master != bitbang_spi_master) {
-		msg_perr("Shutting down a mismatched SPI bitbang master!\n"
-			 "Please report a bug at flashrom@flashrom.org\n");
-		return 1;
-	}
-
-	/* FIXME: Run bitbang_spi_release_bus here or per command? */
-	bitbang_spi_master = NULL;
+	/* Only mess with the bus if we're sure nobody else uses it. */
+	bitbang_spi_request_bus(master);
+	bitbang_spi_set_cs(master, 1);
+	bitbang_spi_set_sck(master, 0);
+	bitbang_spi_set_mosi(master, 0);
+	/* FIXME: Release SPI bus here and request it again for each command or
+	 * don't release it now and only release it on programmer shutdown?
+	 */
+	bitbang_spi_release_bus(master);
 	return 0;
 }
 
-static uint8_t bitbang_spi_readwrite_byte(uint8_t val)
+static uint8_t bitbang_spi_rw_byte(const struct bitbang_spi_master *master,
+				   uint8_t val)
 {
 	uint8_t ret = 0;
 	int i;
 
 	for (i = 7; i >= 0; i--) {
-		bitbang_spi_set_mosi((val >> i) & 1);
-		programmer_delay(bitbang_spi_half_period);
-		bitbang_spi_set_sck(1);
+		bitbang_spi_set_mosi(master, (val >> i) & 1);
+		programmer_delay(master->half_period);
+		bitbang_spi_set_sck(master, 1);
 		ret <<= 1;
-		ret |= bitbang_spi_get_miso();
-		programmer_delay(bitbang_spi_half_period);
-		bitbang_spi_set_sck(0);
+		ret |= bitbang_spi_get_miso(master);
+		programmer_delay(master->half_period);
+		bitbang_spi_set_sck(master, 0);
 	}
 	return ret;
 }
@@ -149,23 +136,24 @@ static int bitbang_spi_send_command(struct flashctx *flash,
 				    unsigned char *readarr)
 {
 	int i;
+	const struct bitbang_spi_master *master = flash->pgm->spi.data;
 
 	/* FIXME: Run bitbang_spi_request_bus here or in programmer init?
 	 * Requesting and releasing the SPI bus is handled in here to allow the
 	 * programmer to use its own SPI engine for native accesses.
 	 */
-	bitbang_spi_request_bus();
-	bitbang_spi_set_cs(0);
+	bitbang_spi_request_bus(master);
+	bitbang_spi_set_cs(master, 0);
 	for (i = 0; i < writecnt; i++)
-		bitbang_spi_readwrite_byte(writearr[i]);
+		bitbang_spi_rw_byte(master, writearr[i]);
 	for (i = 0; i < readcnt; i++)
-		readarr[i] = bitbang_spi_readwrite_byte(0);
+		readarr[i] = bitbang_spi_rw_byte(master, 0);
 
-	programmer_delay(bitbang_spi_half_period);
-	bitbang_spi_set_cs(1);
-	programmer_delay(bitbang_spi_half_period);
+	programmer_delay(master->half_period);
+	bitbang_spi_set_cs(master, 1);
+	programmer_delay(master->half_period);
 	/* FIXME: Run bitbang_spi_release_bus here or in programmer init? */
-	bitbang_spi_release_bus();
+	bitbang_spi_release_bus(master);
 
 	return 0;
 }