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>

3 files changed, 497 insertions, 0 deletions

diff --git a/drivers/iio/frequency/Kconfig b/drivers/iio/frequency/Kconfig
index 0458c92464a3..6aaa33ef4544 100644
--- a/drivers/iio/frequency/Kconfig
+++ b/drivers/iio/frequency/Kconfig
@@ -20,4 +20,22 @@ config AD9523
           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
diff --git a/drivers/iio/frequency/Makefile b/drivers/iio/frequency/Makefile
index 1b5b22417da1..00d26e5d1dc2 100644
--- a/drivers/iio/frequency/Makefile
+++ b/drivers/iio/frequency/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_AD9523) += ad9523.o
+obj-$(CONFIG_ADF4350) += adf4350.o
diff --git a/drivers/iio/frequency/adf4350.c b/drivers/iio/frequency/adf4350.c
new file mode 100644
index 000000000000..fd4c8501aba9
--- /dev/null
+++ b/drivers/iio/frequency/adf4350.c
@@ -0,0 +1,478 @@
+/*
+ * ADF4350/ADF4351 SPI Wideband Synthesizer driver
+ *
+ * Copyright 2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/regulator/consumer.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/gcd.h>
+#include <linux/gpio.h>
+#include <asm/div64.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/frequency/adf4350.h>
+
+enum {
+        ADF4350_FREQ,
+        ADF4350_FREQ_REFIN,
+        ADF4350_FREQ_RESOLUTION,
+        ADF4350_PWRDOWN,
+};
+
+struct adf4350_state {
+        struct spi_device               *spi;
+        struct regulator                *reg;
+        struct adf4350_platform_data    *pdata;
+        unsigned long                   clkin;
+        unsigned long                   chspc; /* Channel Spacing */
+        unsigned long                   fpfd; /* Phase Frequency Detector */
+        unsigned long                   min_out_freq;
+        unsigned                        r0_fract;
+        unsigned                        r0_int;
+        unsigned                        r1_mod;
+        unsigned                        r4_rf_div_sel;
+        unsigned long                   regs[6];
+        unsigned long                   regs_hw[6];
+
+        /*
+         * DMA (thus cache coherency maintenance) requires the
+         * transfer buffers to live in their own cache lines.
+         */
+        __be32                          val ____cacheline_aligned;
+};
+
+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),
+        .r3_user_settings = ADF4350_REG3_12BIT_CLKDIV_MODE(0),
+        .r4_user_settings = ADF4350_REG4_OUTPUT_PWR(3) |
+                            ADF4350_REG4_MUTE_TILL_LOCK_EN,
+        .gpio_lock_detect = -1,
+};
+
+static int adf4350_sync_config(struct adf4350_state *st)
+{
+        int ret, i, doublebuf = 0;
+
+        for (i = ADF4350_REG5; i >= ADF4350_REG0; i--) {
+                if ((st->regs_hw[i] != st->regs[i]) ||
+                        ((i == ADF4350_REG0) && doublebuf)) {
+
+                        switch (i) {
+                        case ADF4350_REG1:
+                        case ADF4350_REG4:
+                                doublebuf = 1;
+                                break;
+                        }
+
+                        st->val  = cpu_to_be32(st->regs[i] | i);
+                        ret = spi_write(st->spi, &st->val, 4);
+                        if (ret < 0)
+                                return ret;
+                        st->regs_hw[i] = st->regs[i];
+                        dev_dbg(&st->spi->dev, "[%d] 0x%X\n",
+                                i, (u32)st->regs[i] | i);
+                }
+        }
+        return 0;
+}
+
+static int adf4350_reg_access(struct iio_dev *indio_dev,
+                              unsigned reg, unsigned writeval,
+                              unsigned *readval)
+{
+        struct adf4350_state *st = iio_priv(indio_dev);
+        int ret;
+
+        if (reg > ADF4350_REG5)
+                return -EINVAL;
+
+        mutex_lock(&indio_dev->mlock);
+        if (readval == NULL) {
+                st->regs[reg] = writeval & ~(BIT(0) | BIT(1) | BIT(2));
+                ret = adf4350_sync_config(st);
+        } else {
+                *readval =  st->regs_hw[reg];
+                ret = 0;
+        }
+        mutex_unlock(&indio_dev->mlock);
+
+        return ret;
+}
+
+static int adf4350_tune_r_cnt(struct adf4350_state *st, unsigned short r_cnt)
+{
+        struct adf4350_platform_data *pdata = st->pdata;
+
+        do {
+                r_cnt++;
+                st->fpfd = (st->clkin * (pdata->ref_doubler_en ? 2 : 1)) /
+                           (r_cnt * (pdata->ref_div2_en ? 2 : 1));
+        } while (st->fpfd > ADF4350_MAX_FREQ_PFD);
+
+        return r_cnt;
+}
+
+static int adf4350_set_freq(struct adf4350_state *st, unsigned long long freq)
+{
+        struct adf4350_platform_data *pdata = st->pdata;
+        u64 tmp;
+        u32 div_gcd, prescaler;
+        u16 mdiv, r_cnt = 0;
+        u8 band_sel_div;
+
+        if (freq > ADF4350_MAX_OUT_FREQ || freq < st->min_out_freq)
+                return -EINVAL;
+
+        if (freq > ADF4350_MAX_FREQ_45_PRESC) {
+                prescaler = ADF4350_REG1_PRESCALER;
+                mdiv = 75;
+        } else {
+                prescaler = 0;
+                mdiv = 23;
+        }
+
+        st->r4_rf_div_sel = 0;
+
+        while (freq < ADF4350_MIN_VCO_FREQ) {
+                freq <<= 1;
+                st->r4_rf_div_sel++;
+        }
+
+        /*
+         * Allow a predefined reference division factor
+         * if not set, compute our own
+         */
+        if (pdata->ref_div_factor)
+                r_cnt = pdata->ref_div_factor - 1;
+
+        do  {
+                r_cnt = adf4350_tune_r_cnt(st, r_cnt);
+
+                st->r1_mod = st->fpfd / st->chspc;
+                while (st->r1_mod > ADF4350_MAX_MODULUS) {
+                        r_cnt = adf4350_tune_r_cnt(st, r_cnt);
+                        st->r1_mod = st->fpfd / st->chspc;
+                }
+
+                tmp = freq * (u64)st->r1_mod + (st->fpfd > 1);
+                do_div(tmp, st->fpfd); /* Div round closest (n + d/2)/d */
+                st->r0_fract = do_div(tmp, st->r1_mod);
+                st->r0_int = tmp;
+        } while (mdiv > st->r0_int);
+
+        band_sel_div = DIV_ROUND_UP(st->fpfd, ADF4350_MAX_BANDSEL_CLK);
+
+        if (st->r0_fract && st->r1_mod) {
+                div_gcd = gcd(st->r1_mod, st->r0_fract);
+                st->r1_mod /= div_gcd;
+                st->r0_fract /= div_gcd;
+        } else {
+                st->r0_fract = 0;
+                st->r1_mod = 1;
+        }
+
+        dev_dbg(&st->spi->dev, "VCO: %llu Hz, PFD %lu Hz\n"
+                "REF_DIV %d, R0_INT %d, R0_FRACT %d\n"
+                "R1_MOD %d, RF_DIV %d\nPRESCALER %s, BAND_SEL_DIV %d\n",
+                freq, st->fpfd, r_cnt, st->r0_int, st->r0_fract, st->r1_mod,
+                1 << st->r4_rf_div_sel, prescaler ? "8/9" : "4/5",
+                band_sel_div);
+
+        st->regs[ADF4350_REG0] = ADF4350_REG0_INT(st->r0_int) |
+                                 ADF4350_REG0_FRACT(st->r0_fract);
+
+        st->regs[ADF4350_REG1] = ADF4350_REG1_PHASE(0) |
+                                 ADF4350_REG1_MOD(st->r1_mod) |
+                                 prescaler;
+
+        st->regs[ADF4350_REG2] =
+                ADF4350_REG2_10BIT_R_CNT(r_cnt) |
+                ADF4350_REG2_DOUBLE_BUFF_EN |
+                (pdata->ref_doubler_en ? ADF4350_REG2_RMULT2_EN : 0) |
+                (pdata->ref_div2_en ? ADF4350_REG2_RDIV2_EN : 0) |
+                (pdata->r2_user_settings & (ADF4350_REG2_PD_POLARITY_POS |
+                ADF4350_REG2_LDP_6ns | ADF4350_REG2_LDF_INT_N |
+                ADF4350_REG2_CHARGE_PUMP_CURR_uA(5000) |
+                ADF4350_REG2_MUXOUT(0x7) | ADF4350_REG2_NOISE_MODE(0x9)));
+
+        st->regs[ADF4350_REG3] = pdata->r3_user_settings &
+                                 (ADF4350_REG3_12BIT_CLKDIV(0xFFF) |
+                                 ADF4350_REG3_12BIT_CLKDIV_MODE(0x3) |
+                                 ADF4350_REG3_12BIT_CSR_EN |
+                                 ADF4351_REG3_CHARGE_CANCELLATION_EN |
+                                 ADF4351_REG3_ANTI_BACKLASH_3ns_EN |
+                                 ADF4351_REG3_BAND_SEL_CLOCK_MODE_HIGH);
+
+        st->regs[ADF4350_REG4] =
+                ADF4350_REG4_FEEDBACK_FUND |
+                ADF4350_REG4_RF_DIV_SEL(st->r4_rf_div_sel) |
+                ADF4350_REG4_8BIT_BAND_SEL_CLKDIV(band_sel_div) |
+                ADF4350_REG4_RF_OUT_EN |
+                (pdata->r4_user_settings &
+                (ADF4350_REG4_OUTPUT_PWR(0x3) |
+                ADF4350_REG4_AUX_OUTPUT_PWR(0x3) |
+                ADF4350_REG4_AUX_OUTPUT_EN |
+                ADF4350_REG4_AUX_OUTPUT_FUND |
+                ADF4350_REG4_MUTE_TILL_LOCK_EN));
+
+        st->regs[ADF4350_REG5] = ADF4350_REG5_LD_PIN_MODE_DIGITAL;
+
+        return adf4350_sync_config(st);
+}
+
+static ssize_t adf4350_write(struct iio_dev *indio_dev,
+                                    uintptr_t private,
+                                    const struct iio_chan_spec *chan,
+                                    const char *buf, size_t len)
+{
+        struct adf4350_state *st = iio_priv(indio_dev);
+        unsigned long long readin;
+        int ret;
+
+        ret = kstrtoull(buf, 10, &readin);
+        if (ret)
+                return ret;
+
+        mutex_lock(&indio_dev->mlock);
+        switch ((u32)private) {
+        case ADF4350_FREQ:
+                ret = adf4350_set_freq(st, readin);
+                break;
+        case ADF4350_FREQ_REFIN:
+                if (readin > ADF4350_MAX_FREQ_REFIN)
+                        ret = -EINVAL;
+                else
+                        st->clkin = readin;
+                break;
+        case ADF4350_FREQ_RESOLUTION:
+                if (readin == 0)
+                        ret = -EINVAL;
+                else
+                        st->chspc = readin;
+                break;
+        case ADF4350_PWRDOWN:
+                if (readin)
+                        st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
+                else
+                        st->regs[ADF4350_REG2] &= ~ADF4350_REG2_POWER_DOWN_EN;
+
+                adf4350_sync_config(st);
+                break;
+        default:
+                ret = -ENODEV;
+        }
+        mutex_unlock(&indio_dev->mlock);
+
+        return ret ? ret : len;
+}
+
+static ssize_t adf4350_read(struct iio_dev *indio_dev,
+                                   uintptr_t private,
+                                   const struct iio_chan_spec *chan,
+                                   char *buf)
+{
+        struct adf4350_state *st = iio_priv(indio_dev);
+        unsigned long long val;
+        int ret = 0;
+
+        mutex_lock(&indio_dev->mlock);
+        switch ((u32)private) {
+        case ADF4350_FREQ:
+                val = (u64)((st->r0_int * st->r1_mod) + st->r0_fract) *
+                        (u64)st->fpfd;
+                do_div(val, st->r1_mod * (1 << st->r4_rf_div_sel));
+                /* PLL unlocked? return error */
+                if (gpio_is_valid(st->pdata->gpio_lock_detect))
+                        if (!gpio_get_value(st->pdata->gpio_lock_detect)) {
+                                dev_dbg(&st->spi->dev, "PLL un-locked\n");
+                                ret = -EBUSY;
+                        }
+                break;
+        case ADF4350_FREQ_REFIN:
+                val = st->clkin;
+                break;
+        case ADF4350_FREQ_RESOLUTION:
+                val = st->chspc;
+                break;
+        case ADF4350_PWRDOWN:
+                val = !!(st->regs[ADF4350_REG2] & ADF4350_REG2_POWER_DOWN_EN);
+                break;
+        }
+        mutex_unlock(&indio_dev->mlock);
+
+        return ret < 0 ? ret : sprintf(buf, "%llu\n", val);
+}
+
+#define _ADF4350_EXT_INFO(_name, _ident) { \
+        .name = _name, \
+        .read = adf4350_read, \
+        .write = adf4350_write, \
+        .private = _ident, \
+}
+
+static const struct iio_chan_spec_ext_info adf4350_ext_info[] = {
+        /* Ideally we use IIO_CHAN_INFO_FREQUENCY, but there are
+         * values > 2^32 in order to support the entire frequency range
+         * in Hz. Using scale is a bit ugly.
+         */
+        _ADF4350_EXT_INFO("frequency", ADF4350_FREQ),
+        _ADF4350_EXT_INFO("frequency_resolution", ADF4350_FREQ_RESOLUTION),
+        _ADF4350_EXT_INFO("refin_frequency", ADF4350_FREQ_REFIN),
+        _ADF4350_EXT_INFO("powerdown", ADF4350_PWRDOWN),
+        { },
+};
+
+static const struct iio_chan_spec adf4350_chan = {
+        .type = IIO_ALTVOLTAGE,
+        .indexed = 1,
+        .output = 1,
+        .ext_info = adf4350_ext_info,
+};
+
+static const struct iio_info adf4350_info = {
+        .debugfs_reg_access = &adf4350_reg_access,
+        .driver_module = THIS_MODULE,
+};
+
+static int __devinit adf4350_probe(struct spi_device *spi)
+{
+        struct adf4350_platform_data *pdata = spi->dev.platform_data;
+        struct iio_dev *indio_dev;
+        struct adf4350_state *st;
+        int ret;
+
+        if (!pdata) {
+                dev_warn(&spi->dev, "no platform data? using default\n");
+
+                pdata = &default_pdata;
+        }
+
+        indio_dev = iio_device_alloc(sizeof(*st));
+        if (indio_dev == NULL)
+                return -ENOMEM;
+
+        st = iio_priv(indio_dev);
+
+        st->reg = regulator_get(&spi->dev, "vcc");
+        if (!IS_ERR(st->reg)) {
+                ret = regulator_enable(st->reg);
+                if (ret)
+                        goto error_put_reg;
+        }
+
+        spi_set_drvdata(spi, indio_dev);
+        st->spi = spi;
+        st->pdata = pdata;
+
+        indio_dev->dev.parent = &spi->dev;
+        indio_dev->name = (pdata->name[0] != 0) ? pdata->name :
+                spi_get_device_id(spi)->name;
+
+        indio_dev->info = &adf4350_info;
+        indio_dev->modes = INDIO_DIRECT_MODE;
+        indio_dev->channels = &adf4350_chan;
+        indio_dev->num_channels = 1;
+
+        st->chspc = pdata->channel_spacing;
+        st->clkin = pdata->clkin;
+
+        st->min_out_freq = spi_get_device_id(spi)->driver_data == 4351 ?
+                ADF4351_MIN_OUT_FREQ : ADF4350_MIN_OUT_FREQ;
+
+        memset(st->regs_hw, 0xFF, sizeof(st->regs_hw));
+
+        if (gpio_is_valid(pdata->gpio_lock_detect)) {
+                ret = gpio_request(pdata->gpio_lock_detect, indio_dev->name);
+                if (ret) {
+                        dev_err(&spi->dev, "fail to request lock detect GPIO-%d",
+                                pdata->gpio_lock_detect);
+                        goto error_disable_reg;
+                }
+                gpio_direction_input(pdata->gpio_lock_detect);
+        }
+
+        if (pdata->power_up_frequency) {
+                ret = adf4350_set_freq(st, pdata->power_up_frequency);
+                if (ret)
+                        goto error_free_gpio;
+        }
+
+        ret = iio_device_register(indio_dev);
+        if (ret)
+                goto error_free_gpio;
+
+        return 0;
+
+error_free_gpio:
+        if (gpio_is_valid(pdata->gpio_lock_detect))
+                gpio_free(pdata->gpio_lock_detect);
+
+error_disable_reg:
+        if (!IS_ERR(st->reg))
+                regulator_disable(st->reg);
+error_put_reg:
+        if (!IS_ERR(st->reg))
+                regulator_put(st->reg);
+
+        iio_device_free(indio_dev);
+
+        return ret;
+}
+
+static int __devexit adf4350_remove(struct spi_device *spi)
+{
+        struct iio_dev *indio_dev = spi_get_drvdata(spi);
+        struct adf4350_state *st = iio_priv(indio_dev);
+        struct regulator *reg = st->reg;
+
+        st->regs[ADF4350_REG2] |= ADF4350_REG2_POWER_DOWN_EN;
+        adf4350_sync_config(st);
+
+        iio_device_unregister(indio_dev);
+
+        if (!IS_ERR(reg)) {
+                regulator_disable(reg);
+                regulator_put(reg);
+        }
+
+        if (gpio_is_valid(st->pdata->gpio_lock_detect))
+                gpio_free(st->pdata->gpio_lock_detect);
+
+        iio_device_free(indio_dev);
+
+        return 0;
+}
+
+static const struct spi_device_id adf4350_id[] = {
+        {"adf4350", 4350},
+        {"adf4351", 4351},
+        {}
+};
+
+static struct spi_driver adf4350_driver = {
+        .driver = {
+                .name   = "adf4350",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = adf4350_probe,
+        .remove         = __devexit_p(adf4350_remove),
+        .id_table       = adf4350_id,
+};
+module_spi_driver(adf4350_driver);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices ADF4350/ADF4351 PLL");
+MODULE_LICENSE("GPL v2");