xref: /freebsd/sys/dev/xilinx/axi_quad_spi.c (revision 61ba55bcf70f2340f9c943c9571113b3fd8eda69)
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 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/bus.h>
43 #include <sys/kernel.h>
44 #include <sys/module.h>
45 #include <sys/malloc.h>
46 #include <sys/rman.h>
47 #include <sys/timeet.h>
48 #include <sys/timetc.h>
49 #include <sys/watchdog.h>
50 
51 #include <dev/spibus/spi.h>
52 #include <dev/spibus/spibusvar.h>
53 
54 #include "spibus_if.h"
55 
56 #include <dev/fdt/fdt_common.h>
57 #include <dev/ofw/openfirm.h>
58 #include <dev/ofw/ofw_bus.h>
59 #include <dev/ofw/ofw_bus_subr.h>
60 
61 #include <machine/bus.h>
62 #include <machine/cpu.h>
63 #include <machine/intr.h>
64 
65 #define	READ4(_sc, _reg)	\
66 	bus_space_read_4(_sc->bst, _sc->bsh, _reg)
67 #define	WRITE4(_sc, _reg, _val)	\
68 	bus_space_write_4(_sc->bst, _sc->bsh, _reg, _val)
69 
70 #define	SPI_SRR		0x40		/* Software reset register */
71 #define	 SRR_RESET	0x0A		/* The only reset value */
72 #define	SPI_CR		0x60		/* Control register */
73 #define	 CR_LSB_FIRST	(1 << 9)	/* LSB first */
74 #define	 CR_MASTER_TI	(1 << 8)	/* Master Transaction Inhibit */
75 #define	 CR_MSS		(1 << 7)	/* Manual Slave Select */
76 #define	 CR_RST_RX	(1 << 6)	/* RX FIFO Reset */
77 #define	 CR_RST_TX	(1 << 5)	/* TX FIFO Reset */
78 #define	 CR_CPHA	(1 << 4)	/* Clock phase */
79 #define	 CR_CPOL	(1 << 3)	/* Clock polarity */
80 #define	 CR_MASTER	(1 << 2)	/* Master (SPI master mode) */
81 #define	 CR_SPE		(1 << 1)	/* SPI system enable */
82 #define	 CR_LOOP	(1 << 0)	/* Local loopback mode */
83 #define	SPI_SR		0x64		/* Status register */
84 #define	 SR_TX_FULL	(1 << 3)	/* Transmit full */
85 #define	 SR_TX_EMPTY	(1 << 2)	/* Transmit empty */
86 #define	 SR_RX_FULL	(1 << 1)	/* Receive full */
87 #define	 SR_RX_EMPTY	(1 << 0)	/* Receive empty */
88 #define	SPI_DTR		0x68		/* Data transmit register */
89 #define	SPI_DRR		0x6C		/* Data receive register */
90 #define	SPI_SSR		0x70		/* Slave select register */
91 #define	SPI_TFOR	0x74		/* Transmit FIFO Occupancy Register */
92 #define	SPI_RFOR	0x78		/* Receive FIFO Occupancy Register */
93 #define	SPI_DGIER	0x1C		/* Device global interrupt enable register */
94 #define	SPI_IPISR	0x20		/* IP interrupt status register */
95 #define	SPI_IPIER	0x28		/* IP interrupt enable register */
96 
97 struct spi_softc {
98 	struct resource		*res[1];
99 	bus_space_tag_t		bst;
100 	bus_space_handle_t	bsh;
101 	void			*ih;
102 };
103 
104 static struct resource_spec spi_spec[] = {
105 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
106 	{ -1, 0 }
107 };
108 
109 static int
110 spi_probe(device_t dev)
111 {
112 
113 	if (!ofw_bus_status_okay(dev))
114 		return (ENXIO);
115 
116 	if (!ofw_bus_is_compatible(dev, "xlnx,xps-spi-3.2"))
117 		return (ENXIO);
118 
119 	device_set_desc(dev, "Xilinx Quad SPI");
120 	return (BUS_PROBE_DEFAULT);
121 }
122 
123 static int
124 spi_attach(device_t dev)
125 {
126 	struct spi_softc *sc;
127 	uint32_t reg;
128 
129 	sc = device_get_softc(dev);
130 
131 	if (bus_alloc_resources(dev, spi_spec, sc->res)) {
132 		device_printf(dev, "could not allocate resources\n");
133 		return (ENXIO);
134 	}
135 
136 	/* Memory interface */
137 	sc->bst = rman_get_bustag(sc->res[0]);
138 	sc->bsh = rman_get_bushandle(sc->res[0]);
139 
140 	/* Reset */
141 	WRITE4(sc, SPI_SRR, SRR_RESET);
142 
143 	DELAY(1000);
144 
145 	reg = (CR_MASTER | CR_MSS | CR_RST_RX | CR_RST_TX);
146 	WRITE4(sc, SPI_CR, reg);
147 	WRITE4(sc, SPI_DGIER, 0);	/* Disable interrupts */
148 
149 	reg = (CR_MASTER | CR_MSS | CR_SPE);
150 	WRITE4(sc, SPI_CR, reg);
151 
152 	device_add_child(dev, "spibus", 0);
153 	return (bus_generic_attach(dev));
154 }
155 
156 static int
157 spi_txrx(struct spi_softc *sc, uint8_t *out_buf,
158     uint8_t *in_buf, int bufsz, int cs)
159 {
160 	uint32_t data;
161 	uint32_t i;
162 
163 	for (i = 0; i < bufsz; i++) {
164 		WRITE4(sc, SPI_DTR, out_buf[i]);
165 
166 		while(!(READ4(sc, SPI_SR) & SR_TX_EMPTY))
167 			continue;
168 
169 		data = READ4(sc, SPI_DRR);
170 		if (in_buf)
171 			in_buf[i] = (data & 0xff);
172 	}
173 
174 	return (0);
175 }
176 
177 static int
178 spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
179 {
180 	struct spi_softc *sc;
181 	uint32_t reg;
182 	uint32_t cs;
183 
184 	sc = device_get_softc(dev);
185 
186 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
187 	    ("%s: TX/RX command sizes should be equal", __func__));
188 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
189 	    ("%s: TX/RX data sizes should be equal", __func__));
190 
191 	/* get the proper chip select */
192 	spibus_get_cs(child, &cs);
193 
194 	cs &= ~SPIBUS_CS_HIGH;
195 
196 	/* Assert CS */
197 	reg = READ4(sc, SPI_SSR);
198 	reg &= ~(1 << cs);
199 	WRITE4(sc, SPI_SSR, reg);
200 
201 	/* Command */
202 	spi_txrx(sc, cmd->tx_cmd, cmd->rx_cmd, cmd->tx_cmd_sz, cs);
203 
204 	/* Data */
205 	spi_txrx(sc, cmd->tx_data, cmd->rx_data, cmd->tx_data_sz, cs);
206 
207 	/* Deassert CS */
208 	reg = READ4(sc, SPI_SSR);
209 	reg |= (1 << cs);
210 	WRITE4(sc, SPI_SSR, reg);
211 
212 	return (0);
213 }
214 
215 static device_method_t spi_methods[] = {
216 	/* Device interface */
217 	DEVMETHOD(device_probe,		spi_probe),
218 	DEVMETHOD(device_attach,	spi_attach),
219 
220 	/* SPI interface */
221 	DEVMETHOD(spibus_transfer,	spi_transfer),
222 	DEVMETHOD_END
223 };
224 
225 static driver_t spi_driver = {
226 	"spi",
227 	spi_methods,
228 	sizeof(struct spi_softc),
229 };
230 
231 DRIVER_MODULE(spi, simplebus, spi_driver, 0, 0);
232