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Diffstat (limited to 'arch/sh/kernel/cpu/adc.c')
-rw-r--r--arch/sh/kernel/cpu/adc.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/adc.c b/arch/sh/kernel/cpu/adc.c
new file mode 100644
index 000000000..d307571d5
--- /dev/null
+++ b/arch/sh/kernel/cpu/adc.c
@@ -0,0 +1,36 @@
+/*
+ * linux/arch/sh/kernel/adc.c -- SH3 on-chip ADC support
+ *
+ * Copyright (C) 2004 Andriy Skulysh <askulysh@image.kiev.ua>
+ */
+
+#include <linux/module.h>
+#include <asm/adc.h>
+#include <asm/io.h>
+
+
+int adc_single(unsigned int channel)
+{
+ int off;
+ unsigned char csr;
+
+ if (channel >= 8) return -1;
+
+ off = (channel & 0x03) << 2;
+
+ csr = __raw_readb(ADCSR);
+ csr = channel | ADCSR_ADST | ADCSR_CKS;
+ __raw_writeb(csr, ADCSR);
+
+ do {
+ csr = __raw_readb(ADCSR);
+ } while ((csr & ADCSR_ADF) == 0);
+
+ csr &= ~(ADCSR_ADF | ADCSR_ADST);
+ __raw_writeb(csr, ADCSR);
+
+ return (((__raw_readb(ADDRAH + off) << 8) |
+ __raw_readb(ADDRAL + off)) >> 6);
+}
+
+EXPORT_SYMBOL(adc_single);