[U-Boot] [PATCH] Davinci: add a pin multiplexer configuration API

Davinci: add a pin multiplexer configuration API.
Creates a method allowing pin settings to be logically grouped into data structure arrays and provids an API to configure the PINMUX settings to enable the relevant pin functions.
Signed-off-by: Nick Thompson nick.thompson@gefanuc.com --- Applies to: u-boot-ti
The PINMUXn definitions are already present in hardware.h.
The number of PINMUX fields per register and the width of the fields needs to be set per SoC. The initial settings are appropriate for at least DA8xx devices. These should be modified in misc.h to support other devices as required.
board/davinci/common/misc.c | 46 ++++++++++++++++++++++++++++++++++++++++++- board/davinci/common/misc.h | 12 +++++++++++ 2 files changed, 57 insertions(+), 1 deletions(-)
diff --git a/board/davinci/common/misc.c b/board/davinci/common/misc.c index ffdc20b..d462d65 100644 --- a/board/davinci/common/misc.c +++ b/board/davinci/common/misc.c @@ -1,6 +1,7 @@ /* * Miscelaneous DaVinci functions. * + * Copyright (C) 2009 Nick Thompson, GE Fanuc Ltd, nick.thompson@gefanuc.com * Copyright (C) 2007 Sergey Kubushyn ksi@koi8.net * Copyright (C) 2008 Lyrtech <www.lyrtech.com> * Copyright (C) 2004 Texas Instruments. @@ -27,7 +28,8 @@ #include <i2c.h> #include <net.h> #include <asm/arch/hardware.h> - +#include <asm/io.h> +#include "misc.h"
DECLARE_GLOBAL_DATA_PTR;
@@ -109,3 +111,45 @@ void dv_configure_mac_address(uint8_t *rom_enetaddr) }
#endif /* DAVINCI_EMAC */ + +/* + * Change the setting of a pin multiplexer field. + * + * Takes an array of pinmux settings similar to: + * + * struct pinmux_config uart_pins[] = { + * { PINMUX8, 2, 7 }, + * { PINMUX9, 2, 0 } + * }; + * + * Stepping through the array, each PINMUXn register has the given value + * set in the pin mux field specified. + * + * The number of pins in the array must be passed (ARRAY_SIZE can provide + * this value conveniently). + * + * Returns 0 if all field numbers and values are in the correct range, + * else returns -1. + */ +int davinci_configure_pin_mux(const struct pinmux_config *pins, int n_pins) +{ + int i; + + for (i = 0; i < n_pins; i++) { + int value = pins[i].value; + int field = pins[i].field; + + if (field < PIN_MUX_NUM_FIELDS && + (value & ~PIN_MUX_FIELD_MASK) == 0) { + int offset = field * PIN_MUX_FIELD_SIZE; + unsigned int mux = pins[i].mux; + unsigned int mask = PIN_MUX_FIELD_MASK << offset; + value <<= offset; + writel(value | (readl(mux) & (~mask)), mux); + } else { + return -1; + } + } + + return 0; +} diff --git a/board/davinci/common/misc.h b/board/davinci/common/misc.h index dc3cc41..f6d8b1b 100644 --- a/board/davinci/common/misc.h +++ b/board/davinci/common/misc.h @@ -22,8 +22,20 @@ #ifndef __MISC_H #define __MISC_H
+/* pin muxer definitions */ +#define PIN_MUX_NUM_FIELDS 8 /* Per register */ +#define PIN_MUX_FIELD_SIZE 4 /* n in bits */ +#define PIN_MUX_FIELD_MASK ((1 << PIN_MUX_FIELD_SIZE) - 1) + +/* pin definition */ +struct pinmux_config { + dv_reg *mux; /* Address of mux register */ + unsigned char value; /* Value to set in field */ + unsigned char field; /* field number */ +};
int dvevm_read_mac_address(uint8_t *buf); void dv_configure_mac_address(uint8_t *rom_enetaddr); +int davinci_configure_pin_mux(const struct pinmux_config *pins, int n_pins);
#endif /* __MISC_H */

On Thu, 29 Oct 2009 15:38:18 +0000 Nick Thompson nick.thompson@gefanuc.com wrote:
+int davinci_configure_pin_mux(const struct pinmux_config *pins, int n_pins) +{
- int i;
- for (i = 0; i < n_pins; i++) {
int value = pins[i].value;
int field = pins[i].field;
if (field < PIN_MUX_NUM_FIELDS &&
(value & ~PIN_MUX_FIELD_MASK) == 0) {
the second line should not be indented as though it is the code subblock; it should fall directly underneath the column where 'field <..' starts, like this:
if (field < PIN_MUX_NUM_FIELDS && (value & ~PIN_MUX_FIELD_MASK) == 0) {
int offset = field * PIN_MUX_FIELD_SIZE;
unsigned int mux = pins[i].mux;
unsigned int mask = PIN_MUX_FIELD_MASK << offset;
also please just declare everything at the top of the function - same for value and field declarations above.
value <<= offset;
writel(value | (readl(mux) & (~mask)), mux);
I guess arm doesn't have setbits32 and friends, huh.
Kim

Dear Kim Phillips,
In message 20091029182304.469c9f7f.kim.phillips@freescale.com you wrote:
if (field < PIN_MUX_NUM_FIELDS &&
(value & ~PIN_MUX_FIELD_MASK) == 0) {
the second line should not be indented as though it is the code subblock; it should fall directly underneath the column where 'field <..' starts, like this:
Agreed.
if (field < PIN_MUX_NUM_FIELDS && (value & ~PIN_MUX_FIELD_MASK) == 0) {
int offset = field * PIN_MUX_FIELD_SIZE;
unsigned int mux = pins[i].mux;
unsigned int mask = PIN_MUX_FIELD_MASK << offset;
also please just declare everything at the top of the function - same for value and field declarations above.
No! Why should that be needed? It would be just a waste of stack space (except that recent compilers don't care abouyt this anyway), and keeping variables as localized as possible seems to be a good thing to me.
value <<= offset;
writel(value | (readl(mux) & (~mask)), mux);
I guess arm doesn't have setbits32 and friends, huh.
Not yet. Patches welcome!
Best regards,
Wolfgang Denk

On Fri, 30 Oct 2009 09:26:12 +0100 Wolfgang Denk wd@denx.de wrote:
Dear Kim Phillips,
In message 20091029182304.469c9f7f.kim.phillips@freescale.com you wrote:
if (field < PIN_MUX_NUM_FIELDS && (value & ~PIN_MUX_FIELD_MASK) == 0) {
int offset = field * PIN_MUX_FIELD_SIZE;
unsigned int mux = pins[i].mux;
unsigned int mask = PIN_MUX_FIELD_MASK << offset;
also please just declare everything at the top of the function - same for value and field declarations above.
No! Why should that be needed? It would be just a waste of stack space (except that recent compilers don't care abouyt this anyway), and keeping variables as localized as possible seems to be a good thing to me.
not when it sacrifices readability. I'm looking for assignments and finding 'unsigned'! Either put a blank line between the declarations and the rest of the code, or declare everything at the top of the function, since it does nothing for the compiler (my preference is the latter in this case).
Kim

From: Kim Phillips [mailto:kim.phillips@freescale.com] Sent: 30 October 2009 14:57
On Fri, 30 Oct 2009 09:26:12 +0100 Wolfgang Denk wd@denx.de wrote:
Dear Kim Phillips,
In message 20091029182304.469c9f7f.kim.phillips@freescale.com you wrote:
if (field < PIN_MUX_NUM_FIELDS && (value & ~PIN_MUX_FIELD_MASK) == 0) {
int offset = field * PIN_MUX_FIELD_SIZE;
unsigned int mux = pins[i].mux;
unsigned int mask = PIN_MUX_FIELD_MASK << offset;
also please just declare everything at the top of the function - same for value and field declarations above.
No! Why should that be needed? It would be just a waste of stack space (except that recent compilers don't care abouyt this anyway), and keeping variables as localized as possible seems to be a good thing to me.
not when it sacrifices readability. I'm looking for assignments and finding 'unsigned'! Either put a blank line between the declarations and the rest of the code, or declare everything at the top of the function, since it does nothing for the compiler (my preference is the latter in this case).
Kim
All three of these declarations could be const, which may or may not help the compiler, but would be technically correct and document my intentions better.
This would not be possible if they where moved to the start of the function or if the declaration and assignments where split up in any other way.
Nick.

On Fri, 30 Oct 2009 15:17:40 +0000 "Thompson, Nick (GE EntSol, Intelligent Platforms)" Nick.Thompson@gefanuc.com wrote:
From: Kim Phillips [mailto:kim.phillips@freescale.com] Sent: 30 October 2009 14:57
On Fri, 30 Oct 2009 09:26:12 +0100 Wolfgang Denk wd@denx.de wrote:
Dear Kim Phillips,
In message 20091029182304.469c9f7f.kim.phillips@freescale.com you wrote:
if (field < PIN_MUX_NUM_FIELDS && (value & ~PIN_MUX_FIELD_MASK) == 0) {
int offset = field * PIN_MUX_FIELD_SIZE;
unsigned int mux = pins[i].mux;
unsigned int mask = PIN_MUX_FIELD_MASK << offset;
also please just declare everything at the top of the function - same for value and field declarations above.
No! Why should that be needed? It would be just a waste of stack space (except that recent compilers don't care abouyt this anyway), and keeping variables as localized as possible seems to be a good thing to me.
not when it sacrifices readability. I'm looking for assignments and finding 'unsigned'! Either put a blank line between the declarations and the rest of the code, or declare everything at the top of the function, since it does nothing for the compiler (my preference is the latter in this case).
Kim
All three of these declarations could be const, which may or may not help the compiler, but would be technically correct and document my intentions better.
This would not be possible if they where moved to the start of the function or if the declaration and assignments where split up in any other way.
Even with a blank line?
Either comply to the level of compiler effectiveness you seek, or make the code more readable for the rest of us.
Kim
participants (4)
-
Kim Phillips
-
Nick Thompson
-
Thompson, Nick (GE EntSol, Intelligent Platforms)
-
Wolfgang Denk