xref: /freebsd/sys/arm/freescale/vybrid/vf_spi.c (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
1 /*-
2  * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 /*
28  * Vybrid Family Serial Peripheral Interface (SPI)
29  * Chapter 47, Vybrid Reference Manual, Rev. 5, 07/2013
30  */
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/malloc.h>
38 #include <sys/rman.h>
39 #include <sys/timeet.h>
40 #include <sys/timetc.h>
41 #include <sys/watchdog.h>
42 
43 #include <dev/spibus/spi.h>
44 #include <dev/spibus/spibusvar.h>
45 
46 #include "spibus_if.h"
47 
48 #include <dev/ofw/openfirm.h>
49 #include <dev/ofw/ofw_bus.h>
50 #include <dev/ofw/ofw_bus_subr.h>
51 
52 #include <machine/bus.h>
53 #include <machine/cpu.h>
54 #include <machine/intr.h>
55 
56 #include <arm/freescale/vybrid/vf_common.h>
57 
58 #define	SPI_FIFO_SIZE	4
59 
60 #define	SPI_MCR		0x00		/* Module Configuration */
61 #define	 MCR_MSTR	(1 << 31)	/* Master/Slave Mode Select */
62 #define	 MCR_CONT_SCKE	(1 << 30)	/* Continuous SCK Enable */
63 #define	 MCR_FRZ	(1 << 27)	/* Freeze */
64 #define	 MCR_PCSIS_S	16		/* Peripheral Chip Select */
65 #define	 MCR_PCSIS_M	0x3f
66 #define	 MCR_MDIS	(1 << 14)	/* Module Disable */
67 #define	 MCR_CLR_TXF	(1 << 11)	/* Clear TX FIFO */
68 #define	 MCR_CLR_RXF	(1 << 10)	/* Clear RX FIFO */
69 #define	 MCR_HALT	(1 << 0)	/* Starts and stops SPI transfers */
70 #define	SPI_TCR		0x08		/* Transfer Count */
71 #define	SPI_CTAR0	0x0C		/* Clock and Transfer Attributes */
72 #define	SPI_CTAR0_SLAVE	0x0C		/* Clock and Transfer Attributes */
73 #define	SPI_CTAR1	0x10		/* Clock and Transfer Attributes */
74 #define	SPI_CTAR2	0x14		/* Clock and Transfer Attributes */
75 #define	SPI_CTAR3	0x18		/* Clock and Transfer Attributes */
76 #define	 CTAR_FMSZ_M	0xf
77 #define	 CTAR_FMSZ_S	27		/* Frame Size */
78 #define	 CTAR_FMSZ_8	0x7		/* 8 bits */
79 #define	 CTAR_CPOL	(1 << 26)	/* Clock Polarity */
80 #define	 CTAR_CPHA	(1 << 25)	/* Clock Phase */
81 #define	 CTAR_LSBFE	(1 << 24)	/* Less significant bit first */
82 #define	 CTAR_PCSSCK_M	0x3
83 #define	 CTAR_PCSSCK_S	22		/* PCS to SCK Delay Prescaler */
84 #define	 CTAR_PBR_M	0x3
85 #define	 CTAR_PBR_S	16		/* Baud Rate Prescaler */
86 #define	 CTAR_PBR_7	0x3		/* Divide by 7 */
87 #define	 CTAR_CSSCK_M	0xf
88 #define	 CTAR_CSSCK_S	12		/* PCS to SCK Delay Scaler */
89 #define	 CTAR_BR_M	0xf
90 #define	 CTAR_BR_S	0		/* Baud Rate Scaler */
91 #define	SPI_SR		0x2C		/* Status Register */
92 #define	 SR_TCF		(1 << 31)	/* Transfer Complete Flag */
93 #define	 SR_EOQF	(1 << 28)	/* End of Queue Flag */
94 #define	 SR_TFFF	(1 << 25)	/* Transmit FIFO Fill Flag */
95 #define	 SR_RFDF	(1 << 17)	/* Receive FIFO Drain Flag */
96 #define	SPI_RSER	0x30		/* DMA/Interrupt Select */
97 #define	 RSER_EOQF_RE	(1 << 28)	/* Finished Request Enable */
98 #define	SPI_PUSHR	0x34		/* PUSH TX FIFO In Master Mode */
99 #define	 PUSHR_CONT	(1 << 31)	/* Continuous Peripheral CS */
100 #define	 PUSHR_EOQ	(1 << 27)	/* End Of Queue */
101 #define	 PUSHR_CTCNT	(1 << 26)	/* Clear Transfer Counter */
102 #define	 PUSHR_PCS_M	0x3f
103 #define	 PUSHR_PCS_S	16		/* Select PCS signals */
104 
105 #define	SPI_PUSHR_SLAVE	0x34	/* PUSH TX FIFO Register In Slave Mode */
106 #define	SPI_POPR	0x38	/* POP RX FIFO Register */
107 #define	SPI_TXFR0	0x3C	/* Transmit FIFO Registers */
108 #define	SPI_TXFR1	0x40
109 #define	SPI_TXFR2	0x44
110 #define	SPI_TXFR3	0x48
111 #define	SPI_RXFR0	0x7C	/* Receive FIFO Registers */
112 #define	SPI_RXFR1	0x80
113 #define	SPI_RXFR2	0x84
114 #define	SPI_RXFR3	0x88
115 
116 struct spi_softc {
117 	struct resource		*res[2];
118 	bus_space_tag_t		bst;
119 	bus_space_handle_t	bsh;
120 	void			*ih;
121 };
122 
123 static struct resource_spec spi_spec[] = {
124 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
125 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
126 	{ -1, 0 }
127 };
128 
129 static int
130 spi_probe(device_t dev)
131 {
132 
133 	if (!ofw_bus_status_okay(dev))
134 		return (ENXIO);
135 
136 	if (!ofw_bus_is_compatible(dev, "fsl,mvf600-spi"))
137 		return (ENXIO);
138 
139 	device_set_desc(dev, "Vybrid Family Serial Peripheral Interface");
140 	return (BUS_PROBE_DEFAULT);
141 }
142 
143 static int
144 spi_attach(device_t dev)
145 {
146 	struct spi_softc *sc;
147 	uint32_t reg;
148 
149 	sc = device_get_softc(dev);
150 
151 	if (bus_alloc_resources(dev, spi_spec, sc->res)) {
152 		device_printf(dev, "could not allocate resources\n");
153 		return (ENXIO);
154 	}
155 
156 	/* Memory interface */
157 	sc->bst = rman_get_bustag(sc->res[0]);
158 	sc->bsh = rman_get_bushandle(sc->res[0]);
159 
160 	reg = READ4(sc, SPI_MCR);
161 	reg |= MCR_MSTR;
162 	reg &= ~(MCR_CONT_SCKE | MCR_MDIS | MCR_FRZ);
163 	reg &= ~(MCR_PCSIS_M << MCR_PCSIS_S);
164 	reg |= (MCR_PCSIS_M << MCR_PCSIS_S);	/* PCS Active low */
165 	reg |= (MCR_CLR_TXF | MCR_CLR_RXF);
166 	WRITE4(sc, SPI_MCR, reg);
167 
168 	reg = READ4(sc, SPI_RSER);
169 	reg |= RSER_EOQF_RE;
170 	WRITE4(sc, SPI_RSER, reg);
171 
172 	reg = READ4(sc, SPI_MCR);
173 	reg &= ~MCR_HALT;
174 	WRITE4(sc, SPI_MCR, reg);
175 
176 	reg = READ4(sc, SPI_CTAR0);
177 	reg &= ~(CTAR_FMSZ_M << CTAR_FMSZ_S);
178 	reg |= (CTAR_FMSZ_8 << CTAR_FMSZ_S);
179 	/*
180 	 * TODO: calculate BR
181 	 * SCK baud rate = ( fsys / PBR ) * (1 + DBR) / BR
182 	 *
183 	 * reg &= ~(CTAR_BR_M << CTAR_BR_S);
184 	 */
185 	reg &= ~CTAR_CPOL; /* Polarity */
186 	reg |= CTAR_CPHA;
187 	/*
188 	 * Set LSB (Less significant bit first)
189 	 * must be used for some applications, e.g. some LCDs
190 	 */
191 	reg |= CTAR_LSBFE;
192 	WRITE4(sc, SPI_CTAR0, reg);
193 
194 	reg = READ4(sc, SPI_CTAR0);
195 	reg &= ~(CTAR_PBR_M << CTAR_PBR_S);
196 	reg |= (CTAR_PBR_7 << CTAR_PBR_S);
197 	WRITE4(sc, SPI_CTAR0, reg);
198 
199 	device_add_child(dev, "spibus", 0);
200 	return (bus_generic_attach(dev));
201 }
202 
203 static int
204 spi_txrx(struct spi_softc *sc, uint8_t *out_buf,
205     uint8_t *in_buf, int bufsz, int cs)
206 {
207 	uint32_t reg, wreg;
208 	uint32_t txcnt;
209 	uint32_t i;
210 
211 	txcnt = 0;
212 
213 	for (i = 0; i < bufsz; i++) {
214 		txcnt++;
215 		wreg = out_buf[i];
216 		wreg |= PUSHR_CONT;
217 		wreg |= (cs << PUSHR_PCS_S);
218 		if (i == 0)
219 			wreg |= PUSHR_CTCNT;
220 		if (i == (bufsz - 1) || txcnt == SPI_FIFO_SIZE)
221 			wreg |= PUSHR_EOQ;
222 		WRITE4(sc, SPI_PUSHR, wreg);
223 
224 		if (i == (bufsz - 1) || txcnt == SPI_FIFO_SIZE) {
225 			txcnt = 0;
226 
227 			/* Wait last entry in a queue to be transmitted */
228 			while((READ4(sc, SPI_SR) & SR_EOQF) == 0)
229 				continue;
230 
231 			reg = READ4(sc, SPI_SR);
232 			reg |= (SR_TCF | SR_EOQF);
233 			WRITE4(sc, SPI_SR, reg);
234 		}
235 
236 		/* Wait until RX FIFO is empty */
237 		while((READ4(sc, SPI_SR) & SR_RFDF) == 0)
238 			continue;
239 
240 		in_buf[i] = READ1(sc, SPI_POPR);
241 	}
242 
243 	return (0);
244 }
245 
246 static int
247 spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
248 {
249 	struct spi_softc *sc;
250 	uint32_t cs;
251 
252 	sc = device_get_softc(dev);
253 
254 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
255 	    ("%s: TX/RX command sizes should be equal", __func__));
256 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
257 	    ("%s: TX/RX data sizes should be equal", __func__));
258 
259 	/* get the proper chip select */
260 	spibus_get_cs(child, &cs);
261 
262 	cs &= ~SPIBUS_CS_HIGH;
263 
264 	/* Command */
265 	spi_txrx(sc, cmd->tx_cmd, cmd->rx_cmd, cmd->tx_cmd_sz, cs);
266 
267 	/* Data */
268 	spi_txrx(sc, cmd->tx_data, cmd->rx_data, cmd->tx_data_sz, cs);
269 
270 	return (0);
271 }
272 
273 static device_method_t spi_methods[] = {
274 	/* Device interface */
275 	DEVMETHOD(device_probe,		spi_probe),
276 	DEVMETHOD(device_attach,	spi_attach),
277 	/* SPI interface */
278 	DEVMETHOD(spibus_transfer,	spi_transfer),
279 	{ 0, 0 }
280 };
281 
282 static driver_t spi_driver = {
283 	"spi",
284 	spi_methods,
285 	sizeof(struct spi_softc),
286 };
287 
288 DRIVER_MODULE(spi, simplebus, spi_driver, 0, 0);
289