parallel: Drop explicit fallback_chip_X boilerplate

A NULL func pointer is necessary and sufficient for the
condition `NULL func pointer => fallback_chip_X' as to not
need this explicit specification.

Therefore drop the explicit need to specify these fallback
callback function pointer in the par_master struct.
This is a reasonable default for every driver in the tree.

Furthermore, move the 'fallback_chip_X()' func from the
generic programmer.c register logic into its relevant
home of parallel.c and make static local to clean up
link-time symbol space.

This simplifies the code and driver development.

Change-Id: If25c0048a07057aa72be6ffa8d8ad7f0a568dcf7
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/71745
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

17 files changed, 70 insertions, 144 deletions

diff --git a/atahpt.c b/atahpt.c
index 89b44c2f8..71fd4d5b5 100644
--- a/atahpt.c
+++ b/atahpt.c
@@ -74,13 +74,7 @@ static int atahpt_shutdown(void *par_data)
 
 static const struct par_master par_master_atahpt = {
 	.chip_readb	= atahpt_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= atahpt_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= atahpt_shutdown,
 };
 
diff --git a/atapromise.c b/atapromise.c
index e1b86381b..9beebf142 100644
--- a/atapromise.c
+++ b/atapromise.c
@@ -113,13 +113,7 @@ static int atapromise_shutdown(void *par_data)
 
 static const struct par_master par_master_atapromise = {
 	.chip_readb	= atapromise_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= atapromise_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= atapromise_shutdown,
 };
 
diff --git a/atavia.c b/atavia.c
index 8af52d69c..f35771a48 100644
--- a/atavia.c
+++ b/atavia.c
@@ -135,13 +135,7 @@ static uint8_t atavia_chip_readb(const struct flashctx *flash, const chipaddr ad
 static const struct par_master lpc_master_atavia = {
 	.map_flash_region	= atavia_map,
 	.chip_readb	= atavia_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= atavia_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 };
 
 static int atavia_init(const struct programmer_cfg *cfg)
diff --git a/drkaiser.c b/drkaiser.c
index 96f2c99e5..ebf511915 100644
--- a/drkaiser.c
+++ b/drkaiser.c
@@ -71,13 +71,7 @@ static int drkaiser_shutdown(void *par_data)
 
 static const struct par_master par_master_drkaiser = {
 	.chip_readb	= drkaiser_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= drkaiser_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= drkaiser_shutdown,
 };
 
diff --git a/gfxnvidia.c b/gfxnvidia.c
index 1d484ead6..b42097513 100644
--- a/gfxnvidia.c
+++ b/gfxnvidia.c
@@ -96,13 +96,7 @@ static int gfxnvidia_shutdown(void *par_data)
 
 static const struct par_master par_master_gfxnvidia = {
 	.chip_readb	= gfxnvidia_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= gfxnvidia_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= gfxnvidia_shutdown,
 };
 
diff --git a/include/programmer.h b/include/programmer.h
index 67e7b4a9f..281a4f693 100644
--- a/include/programmer.h
+++ b/include/programmer.h
@@ -442,12 +442,6 @@ struct par_master {
 int register_par_master(const struct par_master *mst, const enum chipbustype buses, void *data);
 
 /* programmer.c */
-void fallback_chip_writew(const struct flashctx *flash, uint16_t val, chipaddr addr);
-void fallback_chip_writel(const struct flashctx *flash, uint32_t val, chipaddr addr);
-void fallback_chip_writen(const struct flashctx *flash, const uint8_t *buf, chipaddr addr, size_t len);
-uint16_t fallback_chip_readw(const struct flashctx *flash, const chipaddr addr);
-uint32_t fallback_chip_readl(const struct flashctx *flash, const chipaddr addr);
-void fallback_chip_readn(const struct flashctx *flash, uint8_t *buf, const chipaddr addr, size_t len);
 struct registered_master {
 	enum chipbustype buses_supported;
 	struct {
diff --git a/internal.c b/internal.c
index 9b80f3762..f21c4fcb7 100644
--- a/internal.c
+++ b/internal.c
@@ -116,7 +116,6 @@ static const struct par_master par_master_internal = {
 	.chip_writeb	= internal_chip_writeb,
 	.chip_writew	= internal_chip_writew,
 	.chip_writel	= internal_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 };
 
 static int get_params(const struct programmer_cfg *cfg,
diff --git a/it8212.c b/it8212.c
index 8fe2b5985..3c1161d60 100644
--- a/it8212.c
+++ b/it8212.c
@@ -64,13 +64,7 @@ static int it8212_shutdown(void *par_data)
 
 static const struct par_master par_master_it8212 = {
 	.chip_readb	= it8212_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= it8212_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= it8212_shutdown,
 };
 
diff --git a/nic3com.c b/nic3com.c
index efba9793f..a578d4853 100644
--- a/nic3com.c
+++ b/nic3com.c
@@ -91,13 +91,7 @@ static int nic3com_shutdown(void *par_data)
 
 static const struct par_master par_master_nic3com = {
 	.chip_readb	= nic3com_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= nic3com_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= nic3com_shutdown,
 };
 
diff --git a/nicintel.c b/nicintel.c
index 47edbb755..feb07b663 100644
--- a/nicintel.c
+++ b/nicintel.c
@@ -67,13 +67,7 @@ static int nicintel_shutdown(void *par_data)
 
 static const struct par_master par_master_nicintel = {
 	.chip_readb	= nicintel_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= nicintel_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= nicintel_shutdown,
 };
 
diff --git a/nicnatsemi.c b/nicnatsemi.c
index efa879a3b..65377dc6f 100644
--- a/nicnatsemi.c
+++ b/nicnatsemi.c
@@ -78,13 +78,7 @@ static int nicnatsemi_shutdown(void *par_data)
 
 static const struct par_master par_master_nicnatsemi = {
 	.chip_readb	= nicnatsemi_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= nicnatsemi_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= nicnatsemi_shutdown,
 };
 
diff --git a/nicrealtek.c b/nicrealtek.c
index 103ea9ece..5937e35ba 100644
--- a/nicrealtek.c
+++ b/nicrealtek.c
@@ -87,13 +87,7 @@ static int nicrealtek_shutdown(void *data)
 
 static const struct par_master par_master_nicrealtek = {
 	.chip_readb	= nicrealtek_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= nicrealtek_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= nicrealtek_shutdown,
 };
 
diff --git a/parallel.c b/parallel.c
index cea9e7a70..b19372302 100644
--- a/parallel.c
+++ b/parallel.c
@@ -27,19 +27,49 @@ void chip_writeb(const struct flashctx *flash, uint8_t val, chipaddr addr)
 	flash->mst->par.chip_writeb(flash, val, addr);
 }
 
+/* Little-endian fallback for drivers not supporting 16 bit accesses */
+static void fallback_chip_writew(const struct flashctx *flash, uint16_t val,
+			  chipaddr addr)
+{
+	chip_writeb(flash, val & 0xff, addr);
+	chip_writeb(flash, (val >> 8) & 0xff, addr + 1);
+}
+
 void chip_writew(const struct flashctx *flash, uint16_t val, chipaddr addr)
 {
-	flash->mst->par.chip_writew(flash, val, addr);
+	if (flash->mst->par.chip_writew)
+		flash->mst->par.chip_writew(flash, val, addr);
+	fallback_chip_writew(flash, val, addr);
+}
+
+/* Little-endian fallback for drivers not supporting 32 bit accesses */
+static void fallback_chip_writel(const struct flashctx *flash, uint32_t val,
+			  chipaddr addr)
+{
+	chip_writew(flash, val & 0xffff, addr);
+	chip_writew(flash, (val >> 16) & 0xffff, addr + 2);
 }
 
 void chip_writel(const struct flashctx *flash, uint32_t val, chipaddr addr)
 {
-	flash->mst->par.chip_writel(flash, val, addr);
+	if (flash->mst->par.chip_writel)
+		flash->mst->par.chip_writel(flash, val, addr);
+	fallback_chip_writel(flash, val, addr);
+}
+
+static void fallback_chip_writen(const struct flashctx *flash, const uint8_t *buf, chipaddr addr, size_t len)
+{
+	size_t i;
+	for (i = 0; i < len; i++)
+		chip_writeb(flash, buf[i], addr + i);
+	return;
 }
 
 void chip_writen(const struct flashctx *flash, const uint8_t *buf, chipaddr addr, size_t len)
 {
-	flash->mst->par.chip_writen(flash, buf, addr, len);
+	if (flash->mst->par.chip_writen)
+		flash->mst->par.chip_writen(flash, buf, addr, len);
+	fallback_chip_writen(flash, buf, addr, len);
 }
 
 uint8_t chip_readb(const struct flashctx *flash, const chipaddr addr)
@@ -47,20 +77,53 @@ uint8_t chip_readb(const struct flashctx *flash, const chipaddr addr)
 	return flash->mst->par.chip_readb(flash, addr);
 }
 
+/* Little-endian fallback for drivers not supporting 16 bit accesses */
+static uint16_t fallback_chip_readw(const struct flashctx *flash, const chipaddr addr)
+{
+	uint16_t val;
+	val = chip_readb(flash, addr);
+	val |= chip_readb(flash, addr + 1) << 8;
+	return val;
+}
+
 uint16_t chip_readw(const struct flashctx *flash, const chipaddr addr)
 {
-	return flash->mst->par.chip_readw(flash, addr);
+	if (flash->mst->par.chip_readw)
+		return flash->mst->par.chip_readw(flash, addr);
+	return fallback_chip_readw(flash, addr);
+}
+
+/* Little-endian fallback for drivers not supporting 32 bit accesses */
+static uint32_t fallback_chip_readl(const struct flashctx *flash, const chipaddr addr)
+{
+	uint32_t val;
+	val = chip_readw(flash, addr);
+	val |= chip_readw(flash, addr + 2) << 16;
+	return val;
 }
 
 uint32_t chip_readl(const struct flashctx *flash, const chipaddr addr)
 {
-	return flash->mst->par.chip_readl(flash, addr);
+	if (flash->mst->par.chip_readl)
+		return flash->mst->par.chip_readl(flash, addr);
+	return fallback_chip_readl(flash, addr);
+}
+
+static void fallback_chip_readn(const struct flashctx *flash, uint8_t *buf,
+			 chipaddr addr, size_t len)
+{
+	size_t i;
+	for (i = 0; i < len; i++)
+		buf[i] = chip_readb(flash, addr + i);
+	return;
 }
 
 void chip_readn(const struct flashctx *flash, uint8_t *buf, chipaddr addr,
 		size_t len)
 {
-	flash->mst->par.chip_readn(flash, buf, addr, len);
+	if (flash->mst->par.chip_readn)
+		flash->mst->par.chip_readn(flash, buf, addr, len);
+	fallback_chip_readn(flash, buf, addr, len);
 }
 
 int register_par_master(const struct par_master *mst,
@@ -87,9 +150,7 @@ int register_par_master(const struct par_master *mst,
 		return ERROR_FLASHROM_BUG;
 	}
 
-	if (!mst->chip_writeb || !mst->chip_writew || !mst->chip_writel ||
-	    !mst->chip_writen || !mst->chip_readb || !mst->chip_readw ||
-	    !mst->chip_readl || !mst->chip_readn) {
+	if (!mst->chip_writeb || !mst->chip_readb) {
 		msg_perr("%s called with incomplete master definition. "
 			 "Please report a bug at flashrom@flashrom.org\n",
 			 __func__);
diff --git a/programmer.c b/programmer.c
index d4f15a13e..15fd1b88b 100644
--- a/programmer.c
+++ b/programmer.c
@@ -17,57 +17,6 @@
 #include "flash.h"
 #include "programmer.h"
 
-/* Little-endian fallback for drivers not supporting 16 bit accesses */
-void fallback_chip_writew(const struct flashctx *flash, uint16_t val,
-			  chipaddr addr)
-{
-	chip_writeb(flash, val & 0xff, addr);
-	chip_writeb(flash, (val >> 8) & 0xff, addr + 1);
-}
-
-/* Little-endian fallback for drivers not supporting 16 bit accesses */
-uint16_t fallback_chip_readw(const struct flashctx *flash, const chipaddr addr)
-{
-	uint16_t val;
-	val = chip_readb(flash, addr);
-	val |= chip_readb(flash, addr + 1) << 8;
-	return val;
-}
-
-/* Little-endian fallback for drivers not supporting 32 bit accesses */
-void fallback_chip_writel(const struct flashctx *flash, uint32_t val,
-			  chipaddr addr)
-{
-	chip_writew(flash, val & 0xffff, addr);
-	chip_writew(flash, (val >> 16) & 0xffff, addr + 2);
-}
-
-/* Little-endian fallback for drivers not supporting 32 bit accesses */
-uint32_t fallback_chip_readl(const struct flashctx *flash, const chipaddr addr)
-{
-	uint32_t val;
-	val = chip_readw(flash, addr);
-	val |= chip_readw(flash, addr + 2) << 16;
-	return val;
-}
-
-void fallback_chip_writen(const struct flashctx *flash, const uint8_t *buf, chipaddr addr, size_t len)
-{
-	size_t i;
-	for (i = 0; i < len; i++)
-		chip_writeb(flash, buf[i], addr + i);
-	return;
-}
-
-void fallback_chip_readn(const struct flashctx *flash, uint8_t *buf,
-			 chipaddr addr, size_t len)
-{
-	size_t i;
-	for (i = 0; i < len; i++)
-		buf[i] = chip_readb(flash, addr + i);
-	return;
-}
-
 /* The limit of 4 is totally arbitrary. */
 #define MASTERS_MAX 4
 struct registered_master registered_masters[MASTERS_MAX];
diff --git a/satamv.c b/satamv.c
index dcd53c753..fea4c2bae 100644
--- a/satamv.c
+++ b/satamv.c
@@ -88,13 +88,7 @@ static int satamv_shutdown(void *par_data)
 
 static const struct par_master par_master_satamv = {
 	.chip_readb	= satamv_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= satamv_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= satamv_shutdown,
 };
 
diff --git a/satasii.c b/satasii.c
index 011562ef3..e881f966a 100644
--- a/satasii.c
+++ b/satasii.c
@@ -95,13 +95,7 @@ static int satasii_shutdown(void *par_data)
 
 static const struct par_master par_master_satasii = {
 	.chip_readb	= satasii_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
-	.chip_readn	= fallback_chip_readn,
 	.chip_writeb	= satasii_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.shutdown	= satasii_shutdown,
 };
 
diff --git a/serprog.c b/serprog.c
index 4e131e51a..5ddbe3d68 100644
--- a/serprog.c
+++ b/serprog.c
@@ -594,13 +594,8 @@ static void serprog_delay(const struct flashctx *flash, unsigned int usecs)
 static const struct par_master par_master_serprog = {
 	.map_flash_region	= serprog_map,
 	.chip_readb	= serprog_chip_readb,
-	.chip_readw	= fallback_chip_readw,
-	.chip_readl	= fallback_chip_readl,
 	.chip_readn	= serprog_chip_readn,
 	.chip_writeb	= serprog_chip_writeb,
-	.chip_writew	= fallback_chip_writew,
-	.chip_writel	= fallback_chip_writel,
-	.chip_writen	= fallback_chip_writen,
 	.delay		= serprog_delay,
 };