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author | inmarket <andrewh@inmarket.com.au> | 2014-07-09 15:40:03 +1000 |
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committer | inmarket <andrewh@inmarket.com.au> | 2014-07-09 15:40:03 +1000 |
commit | ab9ce99647965d0d3e9ea65ea92ad694c8b8ee1b (patch) | |
tree | 5a84906ce24ed4214ab94d9f74af1a8fe610f8a4 /boards/base/RaspberryPi/rpi_mailbox.c | |
parent | 34cc5e029a21784bf2eeb17f3c22f3914326d982 (diff) | |
download | uGFX-ab9ce99647965d0d3e9ea65ea92ad694c8b8ee1b.tar.gz uGFX-ab9ce99647965d0d3e9ea65ea92ad694c8b8ee1b.tar.bz2 uGFX-ab9ce99647965d0d3e9ea65ea92ad694c8b8ee1b.zip |
Support added for the Raspberry Pi - talking directly to the graphics co-processor.
Diffstat (limited to 'boards/base/RaspberryPi/rpi_mailbox.c')
-rw-r--r-- | boards/base/RaspberryPi/rpi_mailbox.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/boards/base/RaspberryPi/rpi_mailbox.c b/boards/base/RaspberryPi/rpi_mailbox.c new file mode 100644 index 00000000..798cbb1f --- /dev/null +++ b/boards/base/RaspberryPi/rpi_mailbox.c @@ -0,0 +1,47 @@ +/* + * Access system mailboxes + */ +#include "rpi_mailbox.h" + +/* Mailbox memory addresses */ +static volatile unsigned int *MAILBOX0READ = (unsigned int *) (0x2000b880); +static volatile unsigned int *MAILBOX0STATUS = (unsigned int *) (0x2000b898); +static volatile unsigned int *MAILBOX0WRITE = (unsigned int *) (0x2000b8a0); + +/* Bit 31 set in status register if the write mailbox is full */ +#define MAILBOX_FULL 0x80000000 + +/* Bit 30 set in status register if the read mailbox is empty */ +#define MAILBOX_EMPTY 0x40000000 + +unsigned int rpi_readmailbox(unsigned int channel) +{ + unsigned int val; + + if (channel > 15) + return 0xFFFFFFFF; + + /* Wait for mailbox to be full */ + while (*MAILBOX0STATUS & MAILBOX_EMPTY); + + val = *MAILBOX0READ; + + if ((val & 15) == channel) + return (val & 0xFFFFFFF0); + else + return 0xFFFFFFFF; +} + +void rpi_writemailbox(unsigned int channel, unsigned int data) +{ + if (channel > 15) + return; + + if (data & 0x000F) + return; + + /* Wait for mailbox to be not full */ + while (*MAILBOX0STATUS & MAILBOX_FULL); + + *MAILBOX0WRITE = (data | channel); +} |