[media] radio: Add Sanyo LM7000 tuner driver

Add very simple driver for Sanyo LM7000 AM/FM tuner chip. Only FM is supported
as there is no known HW with AM implemented.

This will be used by radio-aimslab and radio-sf16fmi.
Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/radio/Kconfig

@@ -191,6 +191,9 @@ config RADIO_CADET
 	  To compile this driver as a module, choose M here: the
 	  module will be called radio-cadet.
 
+config RADIO_LM7000
+	tristate
+
 config RADIO_RTRACK
 	tristate "AIMSlab RadioTrack (aka RadioReveal) support"
 	depends on ISA && VIDEO_V4L2

drivers/media/radio/Makefile

@@ -28,5 +28,6 @@ obj-$(CONFIG_RADIO_TEF6862) += tef6862.o
 obj-$(CONFIG_RADIO_TIMBERDALE) += radio-timb.o
 obj-$(CONFIG_RADIO_WL1273) += radio-wl1273.o
 obj-$(CONFIG_RADIO_WL128X) += wl128x/
+obj-$(CONFIG_RADIO_LM7000) += lm7000.o
 
 ccflags-y += -Isound

drivers/media/radio/lm7000.c

+/* Sanyo LM7000 tuner chip driver
+ *
+ * Copyright 2012 Ondrej Zary <linux@rainbow-software.org>
+ * based on radio-aimslab.c by M. Kirkwood
+ * and radio-sf16fmi.c by M. Kirkwood and Petr Vandrovec
+ */
+
+#include <linux/delay.h>
+#include <linux/module.h>
+#include "lm7000.h"
+
+MODULE_AUTHOR("Ondrej Zary <linux@rainbow-software.org>");
+MODULE_DESCRIPTION("Routines for Sanyo LM7000 AM/FM radio tuner chip");
+MODULE_LICENSE("GPL");
+
+/* write the 24-bit register, starting with LSB */
+static void lm7000_write(struct lm7000 *lm, u32 val)
+{
+	int i;
+	u8 data;
+
+	for (i = 0; i < 24; i++) {
+		data = val & (1 << i) ? LM7000_DATA : 0;
+		lm->set_pins(lm, data | LM7000_CE);
+		udelay(2);
+		lm->set_pins(lm, data | LM7000_CE | LM7000_CLK);
+		udelay(2);
+		lm->set_pins(lm, data | LM7000_CE);
+		udelay(2);
+	}
+	lm->set_pins(lm, 0);
+}
+
+void lm7000_set_freq(struct lm7000 *lm, u32 freq)
+{
+	freq += 171200;		/* Add 10.7 MHz IF */
+	freq /= 400;		/* Convert to 25 kHz units */
+	lm7000_write(lm, freq | LM7000_FM_25 | LM7000_BIT_FM);
+}
+EXPORT_SYMBOL(lm7000_set_freq);
+
+static int __init lm7000_module_init(void)
+{
+	return 0;
+}
+
+static void __exit lm7000_module_exit(void)
+{
+}
+
+module_init(lm7000_module_init)
+module_exit(lm7000_module_exit)

drivers/media/radio/lm7000.h

+#ifndef __LM7000_H
+#define __LM7000_H
+
+#define LM7000_DATA	(1 << 0)
+#define LM7000_CLK	(1 << 1)
+#define LM7000_CE	(1 << 2)
+
+#define LM7000_FREQ_MASK 0x3fff
+#define LM7000_BIT_T0	(1 << 14)
+#define LM7000_BIT_T1	(1 << 15)
+#define LM7000_BIT_B0	(1 << 16)
+#define LM7000_BIT_B1	(1 << 17)
+#define LM7000_BIT_B2	(1 << 18)
+#define LM7000_BIT_TB	(1 << 19)
+#define LM7000_FM_100	(0 << 20)
+#define LM7000_FM_50	(1 << 20)
+#define LM7000_FM_25	(2 << 20)
+#define LM7000_AM_5	(3 << 20)
+#define LM7000_AM_10	(4 << 20)
+#define LM7000_AM_9	(5 << 20)
+#define LM7000_AM_1	(6 << 20)
+#define LM7000_AM_5_	(7 << 20)
+#define LM7000_BIT_FM	(1 << 23)
+
+
+struct lm7000 {
+	void (*set_pins)(struct lm7000 *lm, u8 pins);
+};
+
+void lm7000_set_freq(struct lm7000 *lm, u32 freq);
+
+#endif /* __LM7000_H */