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author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-11 19:21:23 -0700 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-10-11 19:21:23 -0700 |
commit | dd6d1844af33acb4edd0a40b1770d091a22c94be (patch) | |
tree | e6bd3549919773a13b770324a4dddb51b194b452 /arch/mips/lasat/at93c.c | |
parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6 (diff) | |
parent | [MIPS] tlbex.c: Cleanup __init usage. (diff) | |
download | linux-dev-dd6d1844af33acb4edd0a40b1770d091a22c94be.tar.xz linux-dev-dd6d1844af33acb4edd0a40b1770d091a22c94be.zip |
Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (80 commits)
[MIPS] tlbex.c: Cleanup __init usage.
[MIPS] WRPPMC serial support move to platform device
[MIPS] R1: Fix hazard barriers to make kernels work on R2 also.
[MIPS] VPE: reimplement ELF loader.
[MIPS] cleanup WRPPMC include files
[MIPS] Add BUG_ON assertion for attempt to run kernel on the wrong CPU type.
[MIPS] SMP: Use ISO C struct initializer for local structs.
[MIPS] SMP: Kill useless casts.
[MIPS] Kill num_online_cpus() loops.
[MIPS] SMP: Implement smp_call_function_mask().
[MIPS] Make facility to convert CPU types to strings generally available.
[MIPS] Convert list of CPU types from #define to enum.
[MIPS] Optimize get_unaligned / put_unaligned implementations.
[MIPS] checkfiles: Fix "need space after that ','" errors.
[MIPS] Fix "no space between function name and open parenthesis" warnings.
[MIPS] Allow hardwiring of the CPU type to a single type for optimization.
[MIPS] tlbex: Size optimize code by declaring a few functions inline.
[MIPS] pg-r4k.c: Dump the generated code
[MIPS] Cobalt: Remove cobalt_machine_power_off()
[MIPS] Cobalt: Move reset port definition to arch/mips/cobalt/reset.c
...
Diffstat (limited to 'arch/mips/lasat/at93c.c')
-rw-r--r-- | arch/mips/lasat/at93c.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/arch/mips/lasat/at93c.c b/arch/mips/lasat/at93c.c new file mode 100644 index 000000000000..793e234719a6 --- /dev/null +++ b/arch/mips/lasat/at93c.c @@ -0,0 +1,149 @@ +/* + * Atmel AT93C46 serial eeprom driver + * + * Brian Murphy <brian.murphy@eicon.com> + * + */ +#include <linux/kernel.h> +#include <linux/delay.h> +#include <asm/lasat/lasat.h> +#include <linux/module.h> +#include <linux/init.h> + +#include "at93c.h" + +#define AT93C_ADDR_SHIFT 7 +#define AT93C_ADDR_MAX ((1 << AT93C_ADDR_SHIFT) - 1) +#define AT93C_RCMD (0x6 << AT93C_ADDR_SHIFT) +#define AT93C_WCMD (0x5 << AT93C_ADDR_SHIFT) +#define AT93C_WENCMD 0x260 +#define AT93C_WDSCMD 0x200 + +struct at93c_defs *at93c; + +static void at93c_reg_write(u32 val) +{ + *at93c->reg = val; +} + +static u32 at93c_reg_read(void) +{ + u32 tmp = *at93c->reg; + return tmp; +} + +static u32 at93c_datareg_read(void) +{ + u32 tmp = *at93c->rdata_reg; + return tmp; +} + +static void at93c_cycle_clk(u32 data) +{ + at93c_reg_write(data | at93c->clk); + lasat_ndelay(250); + at93c_reg_write(data & ~at93c->clk); + lasat_ndelay(250); +} + +static void at93c_write_databit(u8 bit) +{ + u32 data = at93c_reg_read(); + if (bit) + data |= 1 << at93c->wdata_shift; + else + data &= ~(1 << at93c->wdata_shift); + + at93c_reg_write(data); + lasat_ndelay(100); + at93c_cycle_clk(data); +} + +static unsigned int at93c_read_databit(void) +{ + u32 data; + + at93c_cycle_clk(at93c_reg_read()); + data = (at93c_datareg_read() >> at93c->rdata_shift) & 1; + return data; +} + +static u8 at93c_read_byte(void) +{ + int i; + u8 data = 0; + + for (i = 0; i <= 7; i++) { + data <<= 1; + data |= at93c_read_databit(); + } + return data; +} + +static void at93c_write_bits(u32 data, int size) +{ + int i; + int shift = size - 1; + u32 mask = (1 << shift); + + for (i = 0; i < size; i++) { + at93c_write_databit((data & mask) >> shift); + data <<= 1; + } +} + +static void at93c_init_op(void) +{ + at93c_reg_write((at93c_reg_read() | at93c->cs) & + ~at93c->clk & ~(1 << at93c->rdata_shift)); + lasat_ndelay(50); +} + +static void at93c_end_op(void) +{ + at93c_reg_write(at93c_reg_read() & ~at93c->cs); + lasat_ndelay(250); +} + +static void at93c_wait(void) +{ + at93c_init_op(); + while (!at93c_read_databit()) + ; + at93c_end_op(); +}; + +static void at93c_disable_wp(void) +{ + at93c_init_op(); + at93c_write_bits(AT93C_WENCMD, 10); + at93c_end_op(); +} + +static void at93c_enable_wp(void) +{ + at93c_init_op(); + at93c_write_bits(AT93C_WDSCMD, 10); + at93c_end_op(); +} + +u8 at93c_read(u8 addr) +{ + u8 byte; + at93c_init_op(); + at93c_write_bits((addr & AT93C_ADDR_MAX)|AT93C_RCMD, 10); + byte = at93c_read_byte(); + at93c_end_op(); + return byte; +} + +void at93c_write(u8 addr, u8 data) +{ + at93c_disable_wp(); + at93c_init_op(); + at93c_write_bits((addr & AT93C_ADDR_MAX)|AT93C_WCMD, 10); + at93c_write_bits(data, 8); + at93c_end_op(); + at93c_wait(); + at93c_enable_wp(); +} |