iio: adc: adrv9002: add warmboot support

Warmboot allows to bypass the Initial calibrations and instead write a
set of known-good calibration coefficients directly to memory. This
improves significantly boot and profile loading times.

The way this is done is by adding a new binary attribute called
'warmboot_coefficients' and another device attribute called
'warmboot_coefficients_file'. The typical workflow looks like:

 1. cat warmboot_coefficients > /lib/firmware/current_profile_coeffs.bin
 2. echo current_profile_coeffs.bin > warmboot_coefficients_file
 3. cat current_profile.json > profile_config

So, looking at the above commands, one first needs to save the
coefficients for the desired profile (note that profile needs to be
loaded with warmboot disabled first so the initial calibrations can run
once). Then, life goes on and we might change to another profile but
when moving back to the same profile (now with warmboot enabled) one can
run 2 and 3 commands to load the profile. When setting up the device, we
see if warmboot is enabled and then we make use of the firmware API to
request the coefficients to load on the device.

Things are done like this mainly to save memory as these coefficients
buffers can be up to 1MB big and the main device object is already quite
big. Like this, we allocate memory for the coefficients only when needed
and free it as soon as we are done with it.

While at it, make sure to directly include 'mutex.h'.

Signed-off-by: Nuno Sa <nuno.sa@analog.com>

Author: nunojsa

drivers/iio/adc/navassa/adrv9002.c

@@ -17,10 +17,12 @@
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
 #include <linux/sysfs.h>
+#include <linux/string.h>
 #include <linux/units.h>
 
 #include "adrv9002.h"
@@ -551,6 +553,7 @@ enum {
 	ADRV9002_HOP_1_TRIGGER,
 	ADRV9002_HOP_2_TRIGGER,
 	ADRV9002_INIT_CALS_RUN,
+	ADRV9002_WARMBOOT_SEL,
 };
 
 static const char * const adrv9002_hop_table[ADRV9002_FH_TABLES_NR + 1] = {
@@ -608,6 +611,9 @@ static ssize_t adrv9002_attr_show(struct device *dev, struct device_attribute *a
 	case ADRV9002_INIT_CALS_RUN:
 		ret = sysfs_emit(buf, "%s\n", adrv9002_init_cals_modes[phy->run_cals]);
 		break;
+	case ADRV9002_WARMBOOT_SEL:
+		ret = sysfs_emit(buf, "%s\n", phy->warm_boot.coeffs_name);
+		break;
 	default:
 		ret = -EINVAL;
 	}
@@ -714,6 +720,23 @@ static int adrv9002_init_cals_set(struct adrv9002_rf_phy *phy, const char *buf)
 	return adrv9002_phy_rerun_cals(phy, &cals, 0);
 }
 
+static int adrv9002_warm_boot_name_save(struct adrv9002_rf_phy *phy, const char *buf)
+{
+	int ret;
+	char *p;
+
+	ret = strscpy(phy->warm_boot.coeffs_name, buf, sizeof(phy->warm_boot.coeffs_name));
+	if (ret < 0)
+		return ret;
+
+	/* Strip trailing newline */
+	p = phy->warm_boot.coeffs_name + strlen(phy->warm_boot.coeffs_name);
+	if (*--p == '\n')
+		*p = '\0';
+
+	return 0;
+}
+
 static int adrv9002_fh_set(const struct adrv9002_rf_phy *phy, const char *buf, u64 address)
 {
 	int ret;
@@ -763,6 +786,9 @@ static ssize_t adrv9002_attr_store(struct device *dev, struct device_attribute *
 	case ADRV9002_INIT_CALS_RUN:
 		ret = adrv9002_init_cals_set(phy, buf);
 		break;
+	case ADRV9002_WARMBOOT_SEL:
+		ret = adrv9002_warm_boot_name_save(phy, buf);
+		break;
 	default:
 		ret = adrv9002_fh_set(phy, buf, iio_attr->address);
 	}
@@ -2494,6 +2520,8 @@ static IIO_DEVICE_ATTR(frequency_hopping_hop2_signal_trigger, 0200, NULL, adrv90
 		       ADRV9002_HOP_2_TRIGGER);
 static IIO_DEVICE_ATTR(initial_calibrations, 0600, adrv9002_attr_show, adrv9002_attr_store,
 		       ADRV9002_INIT_CALS_RUN);
+static IIO_DEVICE_ATTR(warmboot_coefficients_file, 0600, adrv9002_attr_show, adrv9002_attr_store,
+		       ADRV9002_WARMBOOT_SEL);
 
 static struct attribute *adrv9002_sysfs_attrs[] = {
 	&iio_const_attr_initial_calibrations_available.dev_attr.attr,
@@ -2503,6 +2531,7 @@ static struct attribute *adrv9002_sysfs_attrs[] = {
 	&iio_dev_attr_frequency_hopping_hop1_signal_trigger.dev_attr.attr,
 	&iio_dev_attr_frequency_hopping_hop2_signal_trigger.dev_attr.attr,
 	&iio_dev_attr_initial_calibrations.dev_attr.attr,
+	&iio_dev_attr_warmboot_coefficients_file.dev_attr.attr,
 	NULL
 };
 
@@ -2615,6 +2644,33 @@ static int adrv9002_dgpio_config(const struct adrv9002_rf_phy *phy)
 	return 0;
 }
 
+static int adrv9002_init_cals_handle(struct adrv9002_rf_phy *phy)
+{
+	const struct firmware *fw;
+	int ret;
+	u8 errors;
+
+	if (!phy->curr_profile->sysConfig.warmBootEnable || phy->warm_boot.coeffs_name[0] == '\0')
+		goto run_cals;
+
+	dev_dbg(&phy->spi->dev, "Requesting warmboot coefficients: \"%s\"n",
+		phy->warm_boot.coeffs_name);
+
+	ret = request_firmware(&fw, phy->warm_boot.coeffs_name, &phy->spi->dev);
+	if (ret)
+		return ret;
+
+	ret = api_call(phy, adi_adrv9001_cals_InitCals_WarmBoot_Coefficients_UniqueArray_Set,
+		       fw->data, phy->init_cals.chanInitCalMask[0],
+		       phy->init_cals.chanInitCalMask[1]);
+	release_firmware(fw);
+	if (ret)
+		return ret;
+
+run_cals:
+	return api_call(phy, adi_adrv9001_cals_InitCals_Run, &phy->init_cals, 60000, &errors);
+}
+
 static int adrv9001_rx_path_config(struct adrv9002_rf_phy *phy,
 				   const adi_adrv9001_ChannelState_e state)
 {
@@ -3231,7 +3287,6 @@ static struct adi_adrv9001_SpiSettings adrv9002_spi = {
 
 static int adrv9002_setup(struct adrv9002_rf_phy *phy)
 {
-	u8 init_cals_error = 0;
 	int ret;
 	adi_adrv9001_ChannelState_e init_state;
 
@@ -3278,8 +3333,7 @@ static int adrv9002_setup(struct adrv9002_rf_phy *phy)
 			return ret;
 	}
 
-	ret = api_call(phy, adi_adrv9001_cals_InitCals_Run, &phy->init_cals,
-		       60000, &init_cals_error);
+	ret = adrv9002_init_cals_handle(phy);
 	if (ret)
 		return ret;
 
@@ -3631,6 +3685,11 @@ static const char *const rx_gain_type[] = {
 	"Compensated"
 };
 
+static const char *const warm_boot[] = {
+	"Disabled",
+	"Enabled"
+};
+
 static void adrv9002_fill_profile_read(struct adrv9002_rf_phy *phy)
 {
 	struct adi_adrv9001_DeviceSysConfig *sys = &phy->curr_profile->sysConfig;
@@ -3656,6 +3715,7 @@ static void adrv9002_fill_profile_read(struct adrv9002_rf_phy *phy)
 				     "Duplex Mode: %s\n"
 				     "FH enable: %d\n"
 				     "MCS mode: %s\n"
+				     "WarmBoot: %s\n"
 				     "SSI interface: %s\n", clks->deviceClock_kHz * 1000,
 				     clks->clkPllVcoFreq_daHz * 10ULL, clks->armPowerSavingClkDiv,
 				     lo_maps[clks->rx1LoSelect], lo_maps[clks->rx2LoSelect],
@@ -3667,7 +3727,7 @@ static void adrv9002_fill_profile_read(struct adrv9002_rf_phy *phy)
 				     rx_gain_type[rx_cfg[ADRV9002_CHANN_2].profile.gainTableType],
 				     rx->rxInitChannelMask, tx->txInitChannelMask,
 				     duplex[sys->duplexMode], sys->fhModeOn, mcs[sys->mcsMode],
-				     ssi[phy->ssi_type]);
+				     warm_boot[sys->warmBootEnable], ssi[phy->ssi_type]);
 }
 
 int adrv9002_init(struct adrv9002_rf_phy *phy, struct adi_adrv9001_Init *profile)
@@ -4132,6 +4192,70 @@ static ssize_t adrv9002_dpd_tx_coeficcients_write(struct adrv9002_rf_phy *phy, c
 	return ret ? ret : count;
 }
 
+static ssize_t adrv9002_init_cals_bin_read(struct file *filp, struct kobject *kobj,
+					   struct bin_attribute *bin_attr, char *buf, loff_t off,
+					   size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(kobj_to_dev(kobj));
+	struct adrv9002_rf_phy *phy = iio_priv(indio_dev);
+	off_t curr_off = off;
+	int ret = 0, len;
+
+	mutex_lock(&phy->lock);
+	if (!off) {
+		struct adi_adrv9001_Warmboot_CalNumbers cals;
+
+		if (phy->warm_boot.cals) {
+			/*
+			 * Someone stop reading the coefficients in the middle of it or we have
+			 * concurrent cals! As we cannot know which one is it just error out...
+			 */
+			ret = -EBUSY;
+			goto out_unlock;
+		}
+
+		ret = api_call(phy, adi_adrv9001_cals_InitCals_WarmBoot_UniqueEnabledCals_Get,
+			       &cals, phy->init_cals.chanInitCalMask[0],
+			       phy->init_cals.chanInitCalMask[1]);
+		if (ret)
+			goto out_unlock;
+
+		/*
+		 * These coefficients buffers are huge and adrv9002_rf_phy is already quite big.
+		 * That's why we are going with this trouble to allocate + free the memory every
+		 * time one wants to save the current coefficients.
+		 */
+		phy->warm_boot.cals = devm_kzalloc(&phy->spi->dev, cals.warmbootMemoryNumBytes,
+						   GFP_KERNEL);
+		if (!phy->warm_boot.cals)
+			return -ENOMEM;
+
+		ret = api_call(phy,
+			       adi_adrv9001_cals_InitCals_WarmBoot_Coefficients_UniqueArray_Get,
+			       phy->warm_boot.cals, phy->init_cals.chanInitCalMask[0],
+			       phy->init_cals.chanInitCalMask[1]);
+		if (ret)
+			goto out_unlock;
+
+		phy->warm_boot.size = cals.warmbootMemoryNumBytes;
+	}
+
+	len = memory_read_from_buffer(buf, count, &off, phy->warm_boot.cals, phy->warm_boot.size);
+	if (curr_off + count >= phy->warm_boot.size && phy->warm_boot.cals) {
+		/*
+		 * We are done with it. Even if userspace tries to read more,
+		 * @memory_read_from_buffer() will return 0 (EOF) without trying to copy into the
+		 * buffer.
+		 */
+		dev_dbg(&phy->spi->dev, "Freeing memory(%u)...\n", phy->warm_boot.size);
+		devm_kfree(&phy->spi->dev, phy->warm_boot.cals);
+		phy->warm_boot.cals = NULL;
+	}
+out_unlock:
+	mutex_unlock(&phy->lock);
+	return ret ? ret : len;
+}
+
 static int adrv9002_profile_load(struct adrv9002_rf_phy *phy)
 {
 	int ret;
@@ -4162,6 +4286,22 @@ static int adrv9002_profile_load(struct adrv9002_rf_phy *phy)
 	return ret;
 }
 
+static int adrv9002_init_cals_coeffs_name_get(struct adrv9002_rf_phy *phy)
+{
+	const char *init_cals;
+
+	/* Ignore if the profile has no warmboot */
+	if (!phy->profile.sysConfig.warmBootEnable)
+		return 0;
+
+	if (phy->ssi_type == ADI_ADRV9001_SSI_TYPE_CMOS)
+		init_cals = phy->chip->cmos_cals;
+	else
+		init_cals = phy->chip->lvds_cals;
+
+	return strscpy(phy->warm_boot.coeffs_name, init_cals, sizeof(phy->warm_boot.coeffs_name));
+}
+
 static void adrv9002_clk_disable(void *data)
 {
 	struct clk *clk = data;
@@ -4266,6 +4406,8 @@ ADRV9002_DPD_COEFICCIENTS(1, 7);
 static BIN_ATTR(stream_config, 0222, NULL, adrv9002_stream_bin_write, ADRV9002_STREAM_BINARY_SZ);
 static BIN_ATTR(profile_config, 0644, adrv9002_profile_bin_read, adrv9002_profile_bin_write,
 		ADRV9002_PROFILE_MAX_SZ);
+static BIN_ATTR(warmboot_coefficients, 0400, adrv9002_init_cals_bin_read, NULL,
+		ADRV9002_INIT_CALS_COEFFS_MAX);
 
 static int adrv9002_iio_channels_get(struct adrv9002_rf_phy *phy)
 {
@@ -4389,6 +4531,10 @@ int adrv9002_post_init(struct adrv9002_rf_phy *phy)
 	if (ret)
 		return ret;
 
+	ret = adrv9002_init_cals_coeffs_name_get(phy);
+	if (ret < 0)
+		return ret;
+
 	ret = adrv9002_init(phy, &phy->profile);
 	if (ret)
 		return ret;
@@ -4469,6 +4615,10 @@ int adrv9002_post_init(struct adrv9002_rf_phy *phy)
 		}
 	}
 
+	ret = device_create_bin_file(&indio_dev->dev, &bin_attr_warmboot_coefficients);
+	if (ret)
+		return ret;
+
 	api_call(phy, adi_adrv9001_ApiVersion_Get, &api_version);
 	api_call(phy, adi_adrv9001_arm_Version, &arm_version);
 	api_call(phy, adi_adrv9001_SiliconVersion_Get, &silicon_version);
@@ -4493,6 +4643,8 @@ static const struct adrv9002_chip_info adrv9002_info[] = {
 		.num_channels = ARRAY_SIZE(adrv9002_phy_chan),
 		.cmos_profile = "Navassa_CMOS_profile.json",
 		.lvd_profile = "Navassa_LVDS_profile.json",
+		.cmos_cals = "Navassa_CMOS_init_cals.bin",
+		.lvds_cals = "Navassa_LVDS_init_cals.bin",
 		.name = "adrv9002-phy",
 		.n_tx = ADRV9002_CHANN_MAX,
 	},
@@ -4501,6 +4653,8 @@ static const struct adrv9002_chip_info adrv9002_info[] = {
 		.num_channels = ARRAY_SIZE(adrv9002_phy_chan),
 		.cmos_profile = "Navassa_CMOS_profile.json",
 		.lvd_profile = "Navassa_LVDS_profile.json",
+		.cmos_cals = "Navassa_CMOS_init_cals.bin",
+		.lvds_cals = "Navassa_LVDS_init_cals.bin",
 		.name = "adrv9002-phy",
 		.n_tx = ADRV9002_CHANN_MAX,
 		.rx2tx2 = true,
@@ -4510,6 +4664,8 @@ static const struct adrv9002_chip_info adrv9002_info[] = {
 		.num_channels = ARRAY_SIZE(adrv9003_phy_chan),
 		.cmos_profile = "Navassa_CMOS_profile_adrv9003.json",
 		.lvd_profile = "Navassa_LVDS_profile_adrv9003.json",
+		.cmos_cals = "Navassa_CMOS_init_cals_adrv9003.bin",
+		.lvds_cals = "Navassa_LVDS_init_cals_adrv9003.bin",
 		.name = "adrv9003-phy",
 		.n_tx = 1,
 	},
@@ -4518,6 +4674,8 @@ static const struct adrv9002_chip_info adrv9002_info[] = {
 		.num_channels = ARRAY_SIZE(adrv9003_phy_chan),
 		.cmos_profile = "Navassa_CMOS_profile_adrv9003.json",
 		.lvd_profile = "Navassa_LVDS_profile_adrv9003.json",
+		.cmos_cals = "Navassa_CMOS_init_cals_adrv9003.bin",
+		.lvds_cals = "Navassa_LVDS_init_cals_adrv9003.bin",
 		.name = "adrv9003-phy",
 		.n_tx = 1,
 		.rx2tx2 = true,

drivers/iio/adc/navassa/adrv9002.h

@@ -10,6 +10,7 @@
 #ifndef IIO_TRX_ADRV9002_H_
 #define IIO_TRX_ADRV9002_H_
 
+#include <linux/limits.h>
 #include <linux/clk-provider.h>
 #include <linux/clk/clkscale.h>
 #include <linux/delay.h>
@@ -25,6 +26,7 @@
 #include "adi_adrv9001_rx_gaincontrol_types.h"
 #include "adi_adrv9001_rxSettings_types.h"
 #include "adi_adrv9001_ssi_types.h"
+#include "adi_adrv9001_types.h"
 #include "linux_platform.h"
 
 struct iio_chan_spec;
@@ -38,6 +40,8 @@ struct iio_chan_spec;
 #define ADRV9002_RX_MAX_GAIN_IDX	ADI_ADRV9001_RX_GAIN_INDEX_MAX
 #define ADRV9002_DPD_MAX_REGIONS	8
 #define ADRV9002_DPD_FH_MAX_REGIONS	(ADRV9002_DPD_MAX_REGIONS - 1)
+#define ADRV9002_INIT_CALS_COEFFS_MAX	\
+	(ADI_ADRV9001_WB_MAX_NUM_UNIQUE_CALS * ADI_ADRV9001_WB_MAX_NUM_COEFF)
 
 enum {
 	ADRV9002_CHANN_1,
@@ -217,6 +221,8 @@ struct adrv9002_chip_info {
 	const struct iio_chan_spec *channels;
 	const char *cmos_profile;
 	const char *lvd_profile;
+	const char *cmos_cals;
+	const char *lvds_cals;
 	const char *name;
 	u32 num_channels;
 	u32 n_tx;
@@ -229,21 +235,28 @@ struct adrv9002_ext_lo {
 	u16 divider;
 };
 
+struct adrv9002_warm_boot {
+	char coeffs_name[NAME_MAX];
+	u32 size;
+	u8 *cals;
+};
+
 struct adrv9002_rf_phy {
 	const struct adrv9002_chip_info *chip;
 	struct spi_device		*spi;
 	struct iio_dev			*indio_dev;
 	struct gpio_desc		*reset_gpio;
 	struct gpio_desc		*ssi_sync;
 	struct iio_chan_spec		*iio_chan;
+	struct adrv9002_warm_boot	warm_boot;
 	/* Protect against concurrent accesses to the device */
 	struct mutex			lock;
 	struct clk			*clks[NUM_ADRV9002_CLKS];
 	struct adrv9002_clock		clk_priv[NUM_ADRV9002_CLKS];
 	struct clk_onecell_data		clk_data;
 	/* each LO controls two ports (at least) */
 	struct adrv9002_ext_lo		ext_los[ADRV9002_CHANN_MAX];
-	char				profile_buf[350];
+	char				profile_buf[400];
 	size_t				profile_len;
 	char				*bin_attr_buf;
 	u8				*stream_buf;