xref: /freebsd/sys/dev/xilinx/axi_quad_spi.c (revision 6c92544d7c9722a3fe6263134938d1f864c158c5)
1 /*-
2  * Copyright (c) 2016 Ruslan Bukin <br@bsdpad.com>
3  * All rights reserved.
4  *
5  * Portions of this software were developed by SRI International and the
6  * University of Cambridge Computer Laboratory under DARPA/AFRL contract
7  * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
8  *
9  * Portions of this software were developed by the University of Cambridge
10  * Computer Laboratory as part of the CTSRD Project, with support from the
11  * UK Higher Education Innovation Fund (HEIF).
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 /*
36  * Xilinx AXI_QUAD_SPI
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/bus.h>
45 #include <sys/kernel.h>
46 #include <sys/module.h>
47 #include <sys/malloc.h>
48 #include <sys/rman.h>
49 #include <sys/timeet.h>
50 #include <sys/timetc.h>
51 #include <sys/watchdog.h>
52 
53 #include <dev/spibus/spi.h>
54 #include <dev/spibus/spibusvar.h>
55 
56 #include "spibus_if.h"
57 
58 #include <dev/fdt/fdt_common.h>
59 #include <dev/ofw/openfirm.h>
60 #include <dev/ofw/ofw_bus.h>
61 #include <dev/ofw/ofw_bus_subr.h>
62 
63 #include <machine/bus.h>
64 #include <machine/cpu.h>
65 #include <machine/intr.h>
66 
67 #define	READ4(_sc, _reg)	\
68 	bus_space_read_4(_sc->bst, _sc->bsh, _reg)
69 #define	WRITE4(_sc, _reg, _val)	\
70 	bus_space_write_4(_sc->bst, _sc->bsh, _reg, _val)
71 
72 #define	SPI_SRR		0x40		/* Software reset register */
73 #define	 SRR_RESET	0x0A		/* The only reset value */
74 #define	SPI_CR		0x60		/* Control register */
75 #define	 CR_LSB_FIRST	(1 << 9)	/* LSB first */
76 #define	 CR_MASTER_TI	(1 << 8)	/* Master Transaction Inhibit */
77 #define	 CR_MSS		(1 << 7)	/* Manual Slave Select */
78 #define	 CR_RST_RX	(1 << 6)	/* RX FIFO Reset */
79 #define	 CR_RST_TX	(1 << 5)	/* TX FIFO Reset */
80 #define	 CR_CPHA	(1 << 4)	/* Clock phase */
81 #define	 CR_CPOL	(1 << 3)	/* Clock polarity */
82 #define	 CR_MASTER	(1 << 2)	/* Master (SPI master mode) */
83 #define	 CR_SPE		(1 << 1)	/* SPI system enable */
84 #define	 CR_LOOP	(1 << 0)	/* Local loopback mode */
85 #define	SPI_SR		0x64		/* Status register */
86 #define	 SR_TX_FULL	(1 << 3)	/* Transmit full */
87 #define	 SR_TX_EMPTY	(1 << 2)	/* Transmit empty */
88 #define	 SR_RX_FULL	(1 << 1)	/* Receive full */
89 #define	 SR_RX_EMPTY	(1 << 0)	/* Receive empty */
90 #define	SPI_DTR		0x68		/* Data transmit register */
91 #define	SPI_DRR		0x6C		/* Data receive register */
92 #define	SPI_SSR		0x70		/* Slave select register */
93 #define	SPI_TFOR	0x74		/* Transmit FIFO Occupancy Register */
94 #define	SPI_RFOR	0x78		/* Receive FIFO Occupancy Register */
95 #define	SPI_DGIER	0x1C		/* Device global interrupt enable register */
96 #define	SPI_IPISR	0x20		/* IP interrupt status register */
97 #define	SPI_IPIER	0x28		/* IP interrupt enable register */
98 
99 struct spi_softc {
100 	struct resource		*res[1];
101 	bus_space_tag_t		bst;
102 	bus_space_handle_t	bsh;
103 	void			*ih;
104 };
105 
106 static struct resource_spec spi_spec[] = {
107 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
108 	{ -1, 0 }
109 };
110 
111 static int
112 spi_probe(device_t dev)
113 {
114 
115 	if (!ofw_bus_status_okay(dev))
116 		return (ENXIO);
117 
118 	if (!ofw_bus_is_compatible(dev, "xlnx,xps-spi-3.2"))
119 		return (ENXIO);
120 
121 	device_set_desc(dev, "Xilinx Quad SPI");
122 	return (BUS_PROBE_DEFAULT);
123 }
124 
125 static int
126 spi_attach(device_t dev)
127 {
128 	struct spi_softc *sc;
129 	uint32_t reg;
130 
131 	sc = device_get_softc(dev);
132 
133 	if (bus_alloc_resources(dev, spi_spec, sc->res)) {
134 		device_printf(dev, "could not allocate resources\n");
135 		return (ENXIO);
136 	}
137 
138 	/* Memory interface */
139 	sc->bst = rman_get_bustag(sc->res[0]);
140 	sc->bsh = rman_get_bushandle(sc->res[0]);
141 
142 	/* Reset */
143 	WRITE4(sc, SPI_SRR, SRR_RESET);
144 
145 	DELAY(1000);
146 
147 	reg = (CR_MASTER | CR_MSS | CR_RST_RX | CR_RST_TX);
148 	WRITE4(sc, SPI_CR, reg);
149 	WRITE4(sc, SPI_DGIER, 0);	/* Disable interrupts */
150 
151 	reg = (CR_MASTER | CR_MSS | CR_SPE);
152 	WRITE4(sc, SPI_CR, reg);
153 
154 	device_add_child(dev, "spibus", 0);
155 	return (bus_generic_attach(dev));
156 }
157 
158 static int
159 spi_txrx(struct spi_softc *sc, uint8_t *out_buf,
160     uint8_t *in_buf, int bufsz, int cs)
161 {
162 	uint32_t data;
163 	uint32_t i;
164 
165 	for (i = 0; i < bufsz; i++) {
166 		WRITE4(sc, SPI_DTR, out_buf[i]);
167 
168 		while(!(READ4(sc, SPI_SR) & SR_TX_EMPTY))
169 			continue;
170 
171 		data = READ4(sc, SPI_DRR);
172 		if (in_buf)
173 			in_buf[i] = (data & 0xff);
174 	}
175 
176 	return (0);
177 }
178 
179 static int
180 spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
181 {
182 	struct spi_softc *sc;
183 	uint32_t reg;
184 	uint32_t cs;
185 
186 	sc = device_get_softc(dev);
187 
188 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
189 	    ("%s: TX/RX command sizes should be equal", __func__));
190 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
191 	    ("%s: TX/RX data sizes should be equal", __func__));
192 
193 	/* get the proper chip select */
194 	spibus_get_cs(child, &cs);
195 
196 	cs &= ~SPIBUS_CS_HIGH;
197 
198 	/* Assert CS */
199 	reg = READ4(sc, SPI_SSR);
200 	reg &= ~(1 << cs);
201 	WRITE4(sc, SPI_SSR, reg);
202 
203 	/* Command */
204 	spi_txrx(sc, cmd->tx_cmd, cmd->rx_cmd, cmd->tx_cmd_sz, cs);
205 
206 	/* Data */
207 	spi_txrx(sc, cmd->tx_data, cmd->rx_data, cmd->tx_data_sz, cs);
208 
209 	/* Deassert CS */
210 	reg = READ4(sc, SPI_SSR);
211 	reg |= (1 << cs);
212 	WRITE4(sc, SPI_SSR, reg);
213 
214 	return (0);
215 }
216 
217 static device_method_t spi_methods[] = {
218 	/* Device interface */
219 	DEVMETHOD(device_probe,		spi_probe),
220 	DEVMETHOD(device_attach,	spi_attach),
221 
222 	/* SPI interface */
223 	DEVMETHOD(spibus_transfer,	spi_transfer),
224 	DEVMETHOD_END
225 };
226 
227 static driver_t spi_driver = {
228 	"spi",
229 	spi_methods,
230 	sizeof(struct spi_softc),
231 };
232 
233 DRIVER_MODULE(spi, simplebus, spi_driver, 0, 0);
234