[linux-2.6-block.git] / drivers / fpga / ice40-spi.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * FPGA Manager Driver for Lattice iCE40.
 *
 *  Copyright (c) 2016 Joel Holdsworth
 *
 * This driver adds support to the FPGA manager for configuring the SRAM of
 * Lattice iCE40 FPGAs through slave SPI.
 */

#include <linux/fpga/fpga-mgr.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of_gpio.h>
#include <linux/spi/spi.h>
#include <linux/stringify.h>

#define ICE40_SPI_MAX_SPEED 25000000 /* Hz */
#define ICE40_SPI_MIN_SPEED 1000000 /* Hz */

#define ICE40_SPI_RESET_DELAY 1 /* us (>200ns) */
#define ICE40_SPI_HOUSEKEEPING_DELAY 1200 /* us */

#define ICE40_SPI_NUM_ACTIVATION_BYTES DIV_ROUND_UP(49, 8)

struct ice40_fpga_priv {
	struct spi_device *dev;
	struct gpio_desc *reset;
	struct gpio_desc *cdone;
};

static enum fpga_mgr_states ice40_fpga_ops_state(struct fpga_manager *mgr)
{
	struct ice40_fpga_priv *priv = mgr->priv;

	return gpiod_get_value(priv->cdone) ? FPGA_MGR_STATE_OPERATING :
		FPGA_MGR_STATE_UNKNOWN;
}

static int ice40_fpga_ops_write_init(struct fpga_manager *mgr,
				     struct fpga_image_info *info,
				     const char *buf, size_t count)
{
	struct ice40_fpga_priv *priv = mgr->priv;
	struct spi_device *dev = priv->dev;
	struct spi_message message;
	struct spi_transfer assert_cs_then_reset_delay = {
		.cs_change   = 1,
		.delay_usecs = ICE40_SPI_RESET_DELAY
	};
	struct spi_transfer housekeeping_delay_then_release_cs = {
		.delay_usecs = ICE40_SPI_HOUSEKEEPING_DELAY
	};
	int ret;

	if ((info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
		dev_err(&dev->dev,
			"Partial reconfiguration is not supported\n");
		return -ENOTSUPP;
	}

	/* Lock the bus, assert CRESET_B and SS_B and delay >200ns */
	spi_bus_lock(dev->master);

	gpiod_set_value(priv->reset, 1);

	spi_message_init(&message);
	spi_message_add_tail(&assert_cs_then_reset_delay, &message);
	ret = spi_sync_locked(dev, &message);

	/* Come out of reset */
	gpiod_set_value(priv->reset, 0);

	/* Abort if the chip-select failed */
	if (ret)
		goto fail;

	/* Check CDONE is de-asserted i.e. the FPGA is reset */
	if (gpiod_get_value(priv->cdone)) {
		dev_err(&dev->dev, "Device reset failed, CDONE is asserted\n");
		ret = -EIO;
		goto fail;
	}

	/* Wait for the housekeeping to complete, and release SS_B */
	spi_message_init(&message);
	spi_message_add_tail(&housekeeping_delay_then_release_cs, &message);
	ret = spi_sync_locked(dev, &message);

fail:
	spi_bus_unlock(dev->master);

	return ret;
}

static int ice40_fpga_ops_write(struct fpga_manager *mgr,
				const char *buf, size_t count)
{
	struct ice40_fpga_priv *priv = mgr->priv;

	return spi_write(priv->dev, buf, count);
}

static int ice40_fpga_ops_write_complete(struct fpga_manager *mgr,
					 struct fpga_image_info *info)
{
	struct ice40_fpga_priv *priv = mgr->priv;
	struct spi_device *dev = priv->dev;
	const u8 padding[ICE40_SPI_NUM_ACTIVATION_BYTES] = {0};

	/* Check CDONE is asserted */
	if (!gpiod_get_value(priv->cdone)) {
		dev_err(&dev->dev,
			"CDONE was not asserted after firmware transfer\n");
		return -EIO;
	}

	/* Send of zero-padding to activate the firmware */
	return spi_write(dev, padding, sizeof(padding));
}

static const struct fpga_manager_ops ice40_fpga_ops = {
	.state = ice40_fpga_ops_state,
	.write_init = ice40_fpga_ops_write_init,
	.write = ice40_fpga_ops_write,
	.write_complete = ice40_fpga_ops_write_complete,
};

static int ice40_fpga_probe(struct spi_device *spi)
{
	struct device *dev = &spi->dev;
	struct ice40_fpga_priv *priv;
	struct fpga_manager *mgr;
	int ret;

	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->dev = spi;

	/* Check board setup data. */
	if (spi->max_speed_hz > ICE40_SPI_MAX_SPEED) {
		dev_err(dev, "SPI speed is too high, maximum speed is "
			__stringify(ICE40_SPI_MAX_SPEED) "\n");
		return -EINVAL;
	}

	if (spi->max_speed_hz < ICE40_SPI_MIN_SPEED) {
		dev_err(dev, "SPI speed is too low, minimum speed is "
			__stringify(ICE40_SPI_MIN_SPEED) "\n");
		return -EINVAL;
	}

	if (spi->mode & SPI_CPHA) {
		dev_err(dev, "Bad SPI mode, CPHA not supported\n");
		return -EINVAL;
	}

	/* Set up the GPIOs */
	priv->cdone = devm_gpiod_get(dev, "cdone", GPIOD_IN);
	if (IS_ERR(priv->cdone)) {
		ret = PTR_ERR(priv->cdone);
		dev_err(dev, "Failed to get CDONE GPIO: %d\n", ret);
		return ret;
	}

	priv->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(priv->reset)) {
		ret = PTR_ERR(priv->reset);
		dev_err(dev, "Failed to get CRESET_B GPIO: %d\n", ret);
		return ret;
	}

	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
				   &ice40_fpga_ops, priv);
	if (!mgr)
		return -ENOMEM;

	spi_set_drvdata(spi, mgr);

	return fpga_mgr_register(mgr);
}

static int ice40_fpga_remove(struct spi_device *spi)
{
	struct fpga_manager *mgr = spi_get_drvdata(spi);

	fpga_mgr_unregister(mgr);

	return 0;
}

static const struct of_device_id ice40_fpga_of_match[] = {
	{ .compatible = "lattice,ice40-fpga-mgr", },
	{},
};
MODULE_DEVICE_TABLE(of, ice40_fpga_of_match);

static struct spi_driver ice40_fpga_driver = {
	.probe = ice40_fpga_probe,
	.remove = ice40_fpga_remove,
	.driver = {
		.name = "ice40spi",
		.of_match_table = of_match_ptr(ice40_fpga_of_match),
	},
};

module_spi_driver(ice40_fpga_driver);

MODULE_AUTHOR("Joel Holdsworth <joel@airwebreathe.org.uk>");
MODULE_DESCRIPTION("Lattice iCE40 FPGA Manager");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
b886d83c	1	// SPDX-License-Identifier: GPL-2.0-only
21f8ba2e JH	2	/*
	3	* FPGA Manager Driver for Lattice iCE40.
	4	*
	5	* Copyright (c) 2016 Joel Holdsworth
	6	*
21f8ba2e JH	7	* This driver adds support to the FPGA manager for configuring the SRAM of
	8	* Lattice iCE40 FPGAs through slave SPI.
	9	*/
	10
	11	#include <linux/fpga/fpga-mgr.h>
	12	#include <linux/gpio/consumer.h>
	13	#include <linux/module.h>
	14	#include <linux/of_gpio.h>
	15	#include <linux/spi/spi.h>
	16	#include <linux/stringify.h>
	17
	18	#define ICE40_SPI_MAX_SPEED 25000000 /* Hz */
	19	#define ICE40_SPI_MIN_SPEED 1000000 /* Hz */
	20
	21	#define ICE40_SPI_RESET_DELAY 1 /* us (>200ns) */
	22	#define ICE40_SPI_HOUSEKEEPING_DELAY 1200 /* us */
	23
	24	#define ICE40_SPI_NUM_ACTIVATION_BYTES DIV_ROUND_UP(49, 8)
	25
	26	struct ice40_fpga_priv {
	27	struct spi_device *dev;
	28	struct gpio_desc *reset;
	29	struct gpio_desc *cdone;
	30	};
	31
	32	static enum fpga_mgr_states ice40_fpga_ops_state(struct fpga_manager *mgr)
	33	{
	34	struct ice40_fpga_priv *priv = mgr->priv;
	35
	36	return gpiod_get_value(priv->cdone) ? FPGA_MGR_STATE_OPERATING :
	37	FPGA_MGR_STATE_UNKNOWN;
	38	}
	39
	40	static int ice40_fpga_ops_write_init(struct fpga_manager *mgr,
	41	struct fpga_image_info *info,
	42	const char *buf, size_t count)
	43	{
	44	struct ice40_fpga_priv *priv = mgr->priv;
	45	struct spi_device *dev = priv->dev;
	46	struct spi_message message;
	47	struct spi_transfer assert_cs_then_reset_delay = {
	48	.cs_change = 1,
	49	.delay_usecs = ICE40_SPI_RESET_DELAY
	50	};
	51	struct spi_transfer housekeeping_delay_then_release_cs = {
	52	.delay_usecs = ICE40_SPI_HOUSEKEEPING_DELAY
	53	};
	54	int ret;
	55
	56	if ((info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
	57	dev_err(&dev->dev,
	58	"Partial reconfiguration is not supported\n");
	59	return -ENOTSUPP;
	60	}
	61
	62	/* Lock the bus, assert CRESET_B and SS_B and delay >200ns */
	63	spi_bus_lock(dev->master);
	64
	65	gpiod_set_value(priv->reset, 1);
	66
	67	spi_message_init(&message);
	68	spi_message_add_tail(&assert_cs_then_reset_delay, &message);
	69	ret = spi_sync_locked(dev, &message);
	70
71	/* Come out of reset */
72	gpiod_set_value(priv->reset, 0);
73
74	/* Abort if the chip-select failed */
75	if (ret)
76	goto fail;
77
78	/* Check CDONE is de-asserted i.e. the FPGA is reset */
79	if (gpiod_get_value(priv->cdone)) {
80	dev_err(&dev->dev, "Device reset failed, CDONE is asserted\n");
81	ret = -EIO;
82	goto fail;
83	}
84
85	/* Wait for the housekeeping to complete, and release SS_B */
86	spi_message_init(&message);
87	spi_message_add_tail(&housekeeping_delay_then_release_cs, &message);
88	ret = spi_sync_locked(dev, &message);
89
90	fail:
91	spi_bus_unlock(dev->master);
92
93	return ret;
94	}
95
96	static int ice40_fpga_ops_write(struct fpga_manager *mgr,
97	const char *buf, size_t count)
98	{
99	struct ice40_fpga_priv *priv = mgr->priv;
100
101	return spi_write(priv->dev, buf, count);
102	}
103
104	static int ice40_fpga_ops_write_complete(struct fpga_manager *mgr,
105	struct fpga_image_info *info)
106	{
107	struct ice40_fpga_priv *priv = mgr->priv;
108	struct spi_device *dev = priv->dev;
109	const u8 padding[ICE40_SPI_NUM_ACTIVATION_BYTES] = {0};
110
111	/* Check CDONE is asserted */
112	if (!gpiod_get_value(priv->cdone)) {
113	dev_err(&dev->dev,
114	"CDONE was not asserted after firmware transfer\n");
115	return -EIO;
116	}
117
118	/* Send of zero-padding to activate the firmware */
119	return spi_write(dev, padding, sizeof(padding));
120	}
121
122	static const struct fpga_manager_ops ice40_fpga_ops = {
123	.state = ice40_fpga_ops_state,
124	.write_init = ice40_fpga_ops_write_init,
125	.write = ice40_fpga_ops_write,
126	.write_complete = ice40_fpga_ops_write_complete,
127	};
128
129	static int ice40_fpga_probe(struct spi_device *spi)
130	{
131	struct device *dev = &spi->dev;
132	struct ice40_fpga_priv *priv;
7085e2a9	133	struct fpga_manager *mgr;
21f8ba2e JH	134	int ret;
	135
	136	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
	137	if (!priv)
	138	return -ENOMEM;
	139
	140	priv->dev = spi;
	141
	142	/* Check board setup data. */
	143	if (spi->max_speed_hz > ICE40_SPI_MAX_SPEED) {
	144	dev_err(dev, "SPI speed is too high, maximum speed is "
	145	__stringify(ICE40_SPI_MAX_SPEED) "\n");
	146	return -EINVAL;
	147	}
	148
	149	if (spi->max_speed_hz < ICE40_SPI_MIN_SPEED) {
	150	dev_err(dev, "SPI speed is too low, minimum speed is "
	151	__stringify(ICE40_SPI_MIN_SPEED) "\n");
	152	return -EINVAL;
	153	}
	154
	155	if (spi->mode & SPI_CPHA) {
	156	dev_err(dev, "Bad SPI mode, CPHA not supported\n");
	157	return -EINVAL;
	158	}
	159
	160	/* Set up the GPIOs */
	161	priv->cdone = devm_gpiod_get(dev, "cdone", GPIOD_IN);
	162	if (IS_ERR(priv->cdone)) {
	163	ret = PTR_ERR(priv->cdone);
	164	dev_err(dev, "Failed to get CDONE GPIO: %d\n", ret);
	165	return ret;
	166	}
	167
	168	priv->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
	169	if (IS_ERR(priv->reset)) {
	170	ret = PTR_ERR(priv->reset);
	171	dev_err(dev, "Failed to get CRESET_B GPIO: %d\n", ret);
	172	return ret;
	173	}
	174
084181fe AT	175	mgr = devm_fpga_mgr_create(dev, "Lattice iCE40 FPGA Manager",
084181fe AT	176	&ice40_fpga_ops, priv);
7085e2a9 AT	177	if (!mgr)
	178	return -ENOMEM;
	179
	180	spi_set_drvdata(spi, mgr);
	181
084181fe	182	return fpga_mgr_register(mgr);
21f8ba2e JH	183	}
	184
	185	static int ice40_fpga_remove(struct spi_device *spi)
	186	{
7085e2a9 AT	187	struct fpga_manager *mgr = spi_get_drvdata(spi);
	188
	189	fpga_mgr_unregister(mgr);
	190
21f8ba2e JH	191	return 0;
	192	}
	193
	194	static const struct of_device_id ice40_fpga_of_match[] = {
	195	{ .compatible = "lattice,ice40-fpga-mgr", },
	196	{},
	197	};
	198	MODULE_DEVICE_TABLE(of, ice40_fpga_of_match);
	199
	200	static struct spi_driver ice40_fpga_driver = {
	201	.probe = ice40_fpga_probe,
	202	.remove = ice40_fpga_remove,
	203	.driver = {
	204	.name = "ice40spi",
	205	.of_match_table = of_match_ptr(ice40_fpga_of_match),
	206	},
	207	};
	208
	209	module_spi_driver(ice40_fpga_driver);
	210
	211	MODULE_AUTHOR("Joel Holdsworth <joel@airwebreathe.org.uk>");
	212	MODULE_DESCRIPTION("Lattice iCE40 FPGA Manager");
	213	MODULE_LICENSE("GPL v2");