iio: frequency: adf4350: Add support for clock consumer framework

Preferably get clkin (PLL reference clock) from clock framework
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/frequency/adf4350.c

 /*
  * ADF4350/ADF4351 SPI Wideband Synthesizer driver
  *
- * Copyright 2012 Analog Devices Inc.
+ * Copyright 2012-2013 Analog Devices Inc.
  *
  * Licensed under the GPL-2.
  */
@@ -17,6 +17,7 @@
 #include <linux/gcd.h>
 #include <linux/gpio.h>
 #include <asm/div64.h>
+#include <linux/clk.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -33,6 +34,7 @@ struct adf4350_state {
 	struct spi_device		*spi;
 	struct regulator		*reg;
 	struct adf4350_platform_data	*pdata;
+	struct clk			*clk;
 	unsigned long			clkin;
 	unsigned long			chspc; /* Channel Spacing */
 	unsigned long			fpfd; /* Phase Frequency Detector */
@@ -43,7 +45,7 @@ struct adf4350_state {
 	unsigned			r4_rf_div_sel;
 	unsigned long			regs[6];
 	unsigned long			regs_hw[6];
-
+	unsigned long long		freq_req;
 	/*
 	 * DMA (thus cache coherency maintenance) requires the
 	 * transfer buffers to live in their own cache lines.
@@ -52,7 +54,6 @@ struct adf4350_state {
 };
 
 static struct adf4350_platform_data default_pdata = {
-	.clkin = 122880000,
 	.channel_spacing = 10000,
 	.r2_user_settings = ADF4350_REG2_PD_POLARITY_POS |
 			    ADF4350_REG2_CHARGE_PUMP_CURR_uA(2500),
@@ -235,6 +236,7 @@ static int adf4350_set_freq(struct adf4350_state *st, unsigned long long freq)
 		ADF4350_REG4_MUTE_TILL_LOCK_EN));
 
 	st->regs[ADF4350_REG5] = ADF4350_REG5_LD_PIN_MODE_DIGITAL;
+	st->freq_req = freq;
 
 	return adf4350_sync_config(st);
 }
@@ -246,6 +248,7 @@ static ssize_t adf4350_write(struct iio_dev *indio_dev,
 {
 	struct adf4350_state *st = iio_priv(indio_dev);
 	unsigned long long readin;
+	unsigned long tmp;
 	int ret;
 
 	ret = kstrtoull(buf, 10, &readin);
@@ -258,10 +261,23 @@ static ssize_t adf4350_write(struct iio_dev *indio_dev,
 		ret = adf4350_set_freq(st, readin);
 		break;
 	case ADF4350_FREQ_REFIN:
-		if (readin > ADF4350_MAX_FREQ_REFIN)
+		if (readin > ADF4350_MAX_FREQ_REFIN) {
 			ret = -EINVAL;
-		else
-			st->clkin = readin;
+			break;
+		}
+
+		if (st->clk) {
+			tmp = clk_round_rate(st->clk, readin);
+			if (tmp != readin) {
+				ret = -EINVAL;
+				break;
+			}
+			ret = clk_set_rate(st->clk, tmp);
+			if (ret < 0)
+				break;
+		}
+		st->clkin = readin;
+		ret = adf4350_set_freq(st, st->freq_req);
 		break;
 	case ADF4350_FREQ_RESOLUTION:
 		if (readin == 0)
@@ -308,6 +324,9 @@ static ssize_t adf4350_read(struct iio_dev *indio_dev,
 			}
 		break;
 	case ADF4350_FREQ_REFIN:
+		if (st->clk)
+			st->clkin = clk_get_rate(st->clk);
+
 		val = st->clkin;
 		break;
 	case ADF4350_FREQ_RESOLUTION:
@@ -318,6 +337,7 @@ static ssize_t adf4350_read(struct iio_dev *indio_dev,
 		break;
 	default:
 		ret = -EINVAL;
+		val = 0;
 	}
 	mutex_unlock(&indio_dev->mlock);
 
@@ -360,14 +380,24 @@ static int adf4350_probe(struct spi_device *spi)
 	struct adf4350_platform_data *pdata = spi->dev.platform_data;
 	struct iio_dev *indio_dev;
 	struct adf4350_state *st;
+	struct clk *clk = NULL;
 	int ret;
 
 	if (!pdata) {
 		dev_warn(&spi->dev, "no platform data? using default\n");
-
 		pdata = &default_pdata;
 	}
 
+	if (!pdata->clkin) {
+		clk = clk_get(&spi->dev, "clkin");
+		if (IS_ERR(clk))
+			return -EPROBE_DEFER;
+
+		ret = clk_prepare_enable(clk);
+		if (ret < 0)
+			return ret;
+	}
+
 	indio_dev = iio_device_alloc(sizeof(*st));
 	if (indio_dev == NULL)
 		return -ENOMEM;
@@ -395,7 +425,12 @@ static int adf4350_probe(struct spi_device *spi)
 	indio_dev->num_channels = 1;
 
 	st->chspc = pdata->channel_spacing;
-	st->clkin = pdata->clkin;
+	if (clk) {
+		st->clk = clk;
+		st->clkin = clk_get_rate(clk);
+	} else {
+		st->clkin = pdata->clkin;
+	}
 
 	st->min_out_freq = spi_get_device_id(spi)->driver_data == 4351 ?
 		ADF4351_MIN_OUT_FREQ : ADF4350_MIN_OUT_FREQ;
@@ -435,6 +470,8 @@ static int adf4350_probe(struct spi_device *spi)
 	if (!IS_ERR(st->reg))
 		regulator_put(st->reg);
 
+	if (clk)
+		clk_disable_unprepare(clk);
 	iio_device_free(indio_dev);
 
 	return ret;
@@ -451,6 +488,9 @@ static int adf4350_remove(struct spi_device *spi)
 
 	iio_device_unregister(indio_dev);
 
+	if (st->clk)
+		clk_disable_unprepare(st->clk);
+
 	if (!IS_ERR(reg)) {
 		regulator_disable(reg);
 		regulator_put(reg);
@@ -481,6 +521,6 @@ static struct spi_driver adf4350_driver = {
 };
 module_spi_driver(adf4350_driver);
 
-MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 MODULE_DESCRIPTION("Analog Devices ADF4350/ADF4351 PLL");
 MODULE_LICENSE("GPL v2");