diff mbox series

[v2,25/28] asm-generic/io.h: add iowrite{8,16}_32 accessors

Message ID 20240125145007.748295-26-tudor.ambarus@linaro.org
State New
Headers show
Series spi: s3c64xx: winter cleanup and gs101 support | expand

Commit Message

Tudor Ambarus Jan. 25, 2024, 2:50 p.m. UTC 
This will allow devices that require 32 bits register accesses to write
data in chunks of 8 or 16 bits.

One SoC that requires 32 bit register accesses is the google gs101. A
typical use case is SPI, where the clients can request transfers in words
of 8 bits.

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
---
 include/asm-generic/io.h    | 50 +++++++++++++++++++++++++++++++++++++
 include/asm-generic/iomap.h |  2 ++
 2 files changed, 52 insertions(+)

Comments

Mark Brown Jan. 25, 2024, 5:41 p.m. UTC | #1 
On Thu, Jan 25, 2024 at 02:50:03PM +0000, Tudor Ambarus wrote:
> This will allow devices that require 32 bits register accesses to write
> data in chunks of 8 or 16 bits.
> 
> One SoC that requires 32 bit register accesses is the google gs101. A
> typical use case is SPI, where the clients can request transfers in words
> of 8 bits.

Might be good to CC this one to linux-arch if reposting.
Tudor Ambarus Jan. 26, 2024, 7:21 a.m. UTC | #2 
On 1/25/24 21:23, Arnd Bergmann wrote:
> My feeling is that this operation is rare enough that I'd prefer
> it to be open-coded in the driver than made generic here. Making
> it work for all corner cases is possible but probably not worth
> it.

Thanks for all the explanations, Arnd. I'll open-code the op in the SPI
driver for now.

Cheers,
ta
diff mbox series

Patch

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index bac63e874c7b..1e224d1ccc98 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -476,6 +476,21 @@  static inline void writesb(volatile void __iomem *addr, const void *buffer,
 }
 #endif
 
+#ifndef writesb_l
+#define writesb_l writesb_l
+static inline void writesb_l(volatile void __iomem *addr, const void *buffer,
+			     unsigned int count)
+{
+	if (count) {
+		const u8 *buf = buffer;
+
+		do {
+			__raw_writel(*buf++, addr);
+		} while (--count);
+	}
+}
+#endif
+
 #ifndef writesw
 #define writesw writesw
 static inline void writesw(volatile void __iomem *addr, const void *buffer,
@@ -491,6 +506,21 @@  static inline void writesw(volatile void __iomem *addr, const void *buffer,
 }
 #endif
 
+#ifndef writesw_l
+#define writesw_l writesw_l
+static inline void writesw_l(volatile void __iomem *addr, const void *buffer,
+			     unsigned int count)
+{
+	if (count) {
+		const u16 *buf = buffer;
+
+		do {
+			__raw_writel(*buf++, addr);
+		} while (--count);
+	}
+}
+#endif
+
 #ifndef writesl
 #define writesl writesl
 static inline void writesl(volatile void __iomem *addr, const void *buffer,
@@ -956,6 +986,16 @@  static inline void iowrite8_rep(volatile void __iomem *addr,
 }
 #endif
 
+#ifndef iowrite8_32_rep
+#define iowrite8_32_rep iowrite8_32_rep
+static inline void iowrite8_32_rep(volatile void __iomem *addr,
+				   const void *buffer,
+				   unsigned int count)
+{
+	writesb_l(addr, buffer, count);
+}
+#endif
+
 #ifndef iowrite16_rep
 #define iowrite16_rep iowrite16_rep
 static inline void iowrite16_rep(volatile void __iomem *addr,
@@ -966,6 +1006,16 @@  static inline void iowrite16_rep(volatile void __iomem *addr,
 }
 #endif
 
+#ifndef iowrite16_32_rep
+#define iowrite16_32_rep iowrite16_32_rep
+static inline void iowrite16_32_rep(volatile void __iomem *addr,
+				    const void *buffer,
+				    unsigned int count)
+{
+	writesw_l(addr, buffer, count);
+}
+#endif
+
 #ifndef iowrite32_rep
 #define iowrite32_rep iowrite32_rep
 static inline void iowrite32_rep(volatile void __iomem *addr,
diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h
index 196087a8126e..9d63f9adf2db 100644
--- a/include/asm-generic/iomap.h
+++ b/include/asm-generic/iomap.h
@@ -84,7 +84,9 @@  extern void ioread16_rep(const void __iomem *port, void *buf, unsigned long coun
 extern void ioread32_rep(const void __iomem *port, void *buf, unsigned long count);
 
 extern void iowrite8_rep(void __iomem *port, const void *buf, unsigned long count);
+extern void iowrite8_32_rep(void __iomem *port, const void *buf, unsigned long count);
 extern void iowrite16_rep(void __iomem *port, const void *buf, unsigned long count);
+extern void iowrite16_32_rep(void __iomem *port, const void *buf, unsigned long count);
 extern void iowrite32_rep(void __iomem *port, const void *buf, unsigned long count);
 
 #ifdef CONFIG_HAS_IOPORT_MAP