iio: frequency: New driver for Analog Devices ADF4350/ADF4351 Wideband Synthesizers

Changes since V1:
Apply Jonathan's review feedback:
    Introduce and use IIO_ALTVOLTAGE.
    Fix up comments and documentation.
    Remove dead code.
    Reorder some code fragments.
    Add missing iio_device_free.

Convert to new API.
Fix-up out of staging includes.
Removed pll_locked attribute.

Changes since V2:
Use module_spi_driver.
adf4350_remove: move gpio_free after regulator.
target patch to drivers/iio
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350

+What:		/sys/bus/iio/devices/iio:deviceX/out_altvoltageY_frequency_resolution
+KernelVersion:	3.4.0
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Stores channel Y frequency resolution/channel spacing in Hz.
+		The value given directly influences the MODULUS used by
+		the fractional-N PLL. It is assumed that the algorithm
+		that is used to compute the various dividers, is able to
+		generate proper values for multiples of channel spacing.
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_altvoltageY_refin_frequency
+KernelVersion:	3.4.0
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Sets channel Y REFin frequency in Hz. In some clock chained
+		applications, the reference frequency used by the PLL may
+		change during runtime. This attribute allows the user to
+		adjust the reference frequency accordingly.
+		The value written has no effect until out_altvoltageY_frequency
+		is updated. Consider to use out_altvoltageY_powerdown to power
+		down the PLL and it's RFOut buffers during REFin changes.

drivers/iio/frequency/Kconfig

@@ -19,5 +19,23 @@ config AD9523
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad9523.
 
+endmenu
+
+#
+# Phase-Locked Loop (PLL) frequency synthesizers
+#
+
+menu "Phase-Locked Loop (PLL) frequency synthesizers"
+
+config ADF4350
+	tristate "Analog Devices ADF4350/ADF4351 Wideband Synthesizers"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices  ADF4350/ADF4351
+	  Wideband Synthesizers. The driver provides direct access via sysfs.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called adf4350.
+
 endmenu
 endmenu

drivers/iio/frequency/Makefile

@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_AD9523) += ad9523.o
+obj-$(CONFIG_ADF4350) += adf4350.o

include/linux/iio/frequency/adf4350.h

+/*
+ * ADF4350/ADF4351 SPI PLL driver
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef IIO_PLL_ADF4350_H_
+#define IIO_PLL_ADF4350_H_
+
+/* Registers */
+#define ADF4350_REG0	0
+#define ADF4350_REG1	1
+#define ADF4350_REG2	2
+#define ADF4350_REG3	3
+#define ADF4350_REG4	4
+#define ADF4350_REG5	5
+
+/* REG0 Bit Definitions */
+#define ADF4350_REG0_FRACT(x)			(((x) & 0xFFF) << 3)
+#define ADF4350_REG0_INT(x)			(((x) & 0xFFFF) << 15)
+
+/* REG1 Bit Definitions */
+#define ADF4350_REG1_MOD(x)			(((x) & 0xFFF) << 3)
+#define ADF4350_REG1_PHASE(x)			(((x) & 0xFFF) << 15)
+#define ADF4350_REG1_PRESCALER			(1 << 27)
+
+/* REG2 Bit Definitions */
+#define ADF4350_REG2_COUNTER_RESET_EN		(1 << 3)
+#define ADF4350_REG2_CP_THREESTATE_EN		(1 << 4)
+#define ADF4350_REG2_POWER_DOWN_EN		(1 << 5)
+#define ADF4350_REG2_PD_POLARITY_POS		(1 << 6)
+#define ADF4350_REG2_LDP_6ns			(1 << 7)
+#define ADF4350_REG2_LDP_10ns			(0 << 7)
+#define ADF4350_REG2_LDF_FRACT_N		(0 << 8)
+#define ADF4350_REG2_LDF_INT_N			(1 << 8)
+#define ADF4350_REG2_CHARGE_PUMP_CURR_uA(x)	(((((x)-312) / 312) & 0xF) << 9)
+#define ADF4350_REG2_DOUBLE_BUFF_EN		(1 << 13)
+#define ADF4350_REG2_10BIT_R_CNT(x)		((x) << 14)
+#define ADF4350_REG2_RDIV2_EN			(1 << 24)
+#define ADF4350_REG2_RMULT2_EN			(1 << 25)
+#define ADF4350_REG2_MUXOUT(x)			((x) << 26)
+#define ADF4350_REG2_NOISE_MODE(x)		((x) << 29)
+#define ADF4350_MUXOUT_THREESTATE		0
+#define ADF4350_MUXOUT_DVDD			1
+#define ADF4350_MUXOUT_GND			2
+#define ADF4350_MUXOUT_R_DIV_OUT		3
+#define ADF4350_MUXOUT_N_DIV_OUT		4
+#define ADF4350_MUXOUT_ANALOG_LOCK_DETECT	5
+#define ADF4350_MUXOUT_DIGITAL_LOCK_DETECT	6
+
+/* REG3 Bit Definitions */
+#define ADF4350_REG3_12BIT_CLKDIV(x)		((x) << 3)
+#define ADF4350_REG3_12BIT_CLKDIV_MODE(x)	((x) << 16)
+#define ADF4350_REG3_12BIT_CSR_EN		(1 << 18)
+#define ADF4351_REG3_CHARGE_CANCELLATION_EN	(1 << 21)
+#define ADF4351_REG3_ANTI_BACKLASH_3ns_EN	(1 << 22)
+#define ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH	(1 << 23)
+
+/* REG4 Bit Definitions */
+#define ADF4350_REG4_OUTPUT_PWR(x)		((x) << 3)
+#define ADF4350_REG4_RF_OUT_EN			(1 << 5)
+#define ADF4350_REG4_AUX_OUTPUT_PWR(x)		((x) << 6)
+#define ADF4350_REG4_AUX_OUTPUT_EN		(1 << 8)
+#define ADF4350_REG4_AUX_OUTPUT_FUND		(1 << 9)
+#define ADF4350_REG4_AUX_OUTPUT_DIV		(0 << 9)
+#define ADF4350_REG4_MUTE_TILL_LOCK_EN		(1 << 10)
+#define ADF4350_REG4_VCO_PWRDOWN_EN		(1 << 11)
+#define ADF4350_REG4_8BIT_BAND_SEL_CLKDIV(x)	((x) << 12)
+#define ADF4350_REG4_RF_DIV_SEL(x)		((x) << 20)
+#define ADF4350_REG4_FEEDBACK_DIVIDED		(0 << 23)
+#define ADF4350_REG4_FEEDBACK_FUND		(1 << 23)
+
+/* REG5 Bit Definitions */
+#define ADF4350_REG5_LD_PIN_MODE_LOW		(0 << 22)
+#define ADF4350_REG5_LD_PIN_MODE_DIGITAL	(1 << 22)
+#define ADF4350_REG5_LD_PIN_MODE_HIGH		(3 << 22)
+
+/* Specifications */
+#define ADF4350_MAX_OUT_FREQ		4400000000ULL /* Hz */
+#define ADF4350_MIN_OUT_FREQ		137500000 /* Hz */
+#define ADF4351_MIN_OUT_FREQ		34375000 /* Hz */
+#define ADF4350_MIN_VCO_FREQ		2200000000ULL /* Hz */
+#define ADF4350_MAX_FREQ_45_PRESC	3000000000ULL /* Hz */
+#define ADF4350_MAX_FREQ_PFD		32000000 /* Hz */
+#define ADF4350_MAX_BANDSEL_CLK		125000 /* Hz */
+#define ADF4350_MAX_FREQ_REFIN		250000000 /* Hz */
+#define ADF4350_MAX_MODULUS		4095
+
+/**
+ * struct adf4350_platform_data - platform specific information
+ * @name:		Optional device name.
+ * @clkin:		REFin frequency in Hz.
+ * @channel_spacing:	Channel spacing in Hz (influences MODULUS).
+ * @power_up_frequency:	Optional, If set in Hz the PLL tunes to the desired
+ *			frequency on probe.
+ * @ref_div_factor:	Optional, if set the driver skips dynamic calculation
+ *			and uses this default value instead.
+ * @ref_doubler_en:	Enables reference doubler.
+ * @ref_div2_en:	Enables reference divider.
+ * @r2_user_settings:	User defined settings for ADF4350/1 REGISTER_2.
+ * @r3_user_settings:	User defined settings for ADF4350/1 REGISTER_3.
+ * @r4_user_settings:	User defined settings for ADF4350/1 REGISTER_4.
+ * @gpio_lock_detect:	Optional, if set with a valid GPIO number,
+ *			pll lock state is tested upon read.
+ *			If not used - set to -1.
+ */
+
+struct adf4350_platform_data {
+	char			name[32];
+	unsigned long		clkin;
+	unsigned long		channel_spacing;
+	unsigned long long	power_up_frequency;
+
+	unsigned short		ref_div_factor; /* 10-bit R counter */
+	bool			ref_doubler_en;
+	bool			ref_div2_en;
+
+	unsigned		r2_user_settings;
+	unsigned		r3_user_settings;
+	unsigned		r4_user_settings;
+	int			gpio_lock_detect;
+};
+
+#endif /* IIO_PLL_ADF4350_H_ */