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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-11 19:21:23 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-11 19:21:23 -0700
commitdd6d1844af33acb4edd0a40b1770d091a22c94be (patch)
treee6bd3549919773a13b770324a4dddb51b194b452 /arch/mips/lasat/at93c.c
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6 (diff)
parent[MIPS] tlbex.c: Cleanup __init usage. (diff)
downloadlinux-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.c149
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();
+}