xref: /freebsd/sys/arm/freescale/vybrid/vf_spi.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
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/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40 #include <sys/malloc.h>
41 #include <sys/rman.h>
42 #include <sys/timeet.h>
43 #include <sys/timetc.h>
44 #include <sys/watchdog.h>
45 
46 #include <dev/spibus/spi.h>
47 #include <dev/spibus/spibusvar.h>
48 
49 #include "spibus_if.h"
50 
51 #include <dev/ofw/openfirm.h>
52 #include <dev/ofw/ofw_bus.h>
53 #include <dev/ofw/ofw_bus_subr.h>
54 
55 #include <machine/bus.h>
56 #include <machine/cpu.h>
57 #include <machine/intr.h>
58 
59 #include <arm/freescale/vybrid/vf_common.h>
60 
61 #define	SPI_FIFO_SIZE	4
62 
63 #define	SPI_MCR		0x00		/* Module Configuration */
64 #define	 MCR_MSTR	(1 << 31)	/* Master/Slave Mode Select */
65 #define	 MCR_CONT_SCKE	(1 << 30)	/* Continuous SCK Enable */
66 #define	 MCR_FRZ	(1 << 27)	/* Freeze */
67 #define	 MCR_PCSIS_S	16		/* Peripheral Chip Select */
68 #define	 MCR_PCSIS_M	0x3f
69 #define	 MCR_MDIS	(1 << 14)	/* Module Disable */
70 #define	 MCR_CLR_TXF	(1 << 11)	/* Clear TX FIFO */
71 #define	 MCR_CLR_RXF	(1 << 10)	/* Clear RX FIFO */
72 #define	 MCR_HALT	(1 << 0)	/* Starts and stops SPI transfers */
73 #define	SPI_TCR		0x08		/* Transfer Count */
74 #define	SPI_CTAR0	0x0C		/* Clock and Transfer Attributes */
75 #define	SPI_CTAR0_SLAVE	0x0C		/* Clock and Transfer Attributes */
76 #define	SPI_CTAR1	0x10		/* Clock and Transfer Attributes */
77 #define	SPI_CTAR2	0x14		/* Clock and Transfer Attributes */
78 #define	SPI_CTAR3	0x18		/* Clock and Transfer Attributes */
79 #define	 CTAR_FMSZ_M	0xf
80 #define	 CTAR_FMSZ_S	27		/* Frame Size */
81 #define	 CTAR_FMSZ_8	0x7		/* 8 bits */
82 #define	 CTAR_CPOL	(1 << 26)	/* Clock Polarity */
83 #define	 CTAR_CPHA	(1 << 25)	/* Clock Phase */
84 #define	 CTAR_LSBFE	(1 << 24)	/* Less significant bit first */
85 #define	 CTAR_PCSSCK_M	0x3
86 #define	 CTAR_PCSSCK_S	22		/* PCS to SCK Delay Prescaler */
87 #define	 CTAR_PBR_M	0x3
88 #define	 CTAR_PBR_S	16		/* Baud Rate Prescaler */
89 #define	 CTAR_PBR_7	0x3		/* Divide by 7 */
90 #define	 CTAR_CSSCK_M	0xf
91 #define	 CTAR_CSSCK_S	12		/* PCS to SCK Delay Scaler */
92 #define	 CTAR_BR_M	0xf
93 #define	 CTAR_BR_S	0		/* Baud Rate Scaler */
94 #define	SPI_SR		0x2C		/* Status Register */
95 #define	 SR_TCF		(1 << 31)	/* Transfer Complete Flag */
96 #define	 SR_EOQF	(1 << 28)	/* End of Queue Flag */
97 #define	 SR_TFFF	(1 << 25)	/* Transmit FIFO Fill Flag */
98 #define	 SR_RFDF	(1 << 17)	/* Receive FIFO Drain Flag */
99 #define	SPI_RSER	0x30		/* DMA/Interrupt Select */
100 #define	 RSER_EOQF_RE	(1 << 28)	/* Finished Request Enable */
101 #define	SPI_PUSHR	0x34		/* PUSH TX FIFO In Master Mode */
102 #define	 PUSHR_CONT	(1 << 31)	/* Continuous Peripheral CS */
103 #define	 PUSHR_EOQ	(1 << 27)	/* End Of Queue */
104 #define	 PUSHR_CTCNT	(1 << 26)	/* Clear Transfer Counter */
105 #define	 PUSHR_PCS_M	0x3f
106 #define	 PUSHR_PCS_S	16		/* Select PCS signals */
107 
108 #define	SPI_PUSHR_SLAVE	0x34	/* PUSH TX FIFO Register In Slave Mode */
109 #define	SPI_POPR	0x38	/* POP RX FIFO Register */
110 #define	SPI_TXFR0	0x3C	/* Transmit FIFO Registers */
111 #define	SPI_TXFR1	0x40
112 #define	SPI_TXFR2	0x44
113 #define	SPI_TXFR3	0x48
114 #define	SPI_RXFR0	0x7C	/* Receive FIFO Registers */
115 #define	SPI_RXFR1	0x80
116 #define	SPI_RXFR2	0x84
117 #define	SPI_RXFR3	0x88
118 
119 struct spi_softc {
120 	struct resource		*res[2];
121 	bus_space_tag_t		bst;
122 	bus_space_handle_t	bsh;
123 	void			*ih;
124 };
125 
126 static struct resource_spec spi_spec[] = {
127 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
128 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
129 	{ -1, 0 }
130 };
131 
132 static int
133 spi_probe(device_t dev)
134 {
135 
136 	if (!ofw_bus_status_okay(dev))
137 		return (ENXIO);
138 
139 	if (!ofw_bus_is_compatible(dev, "fsl,mvf600-spi"))
140 		return (ENXIO);
141 
142 	device_set_desc(dev, "Vybrid Family Serial Peripheral Interface");
143 	return (BUS_PROBE_DEFAULT);
144 }
145 
146 static int
147 spi_attach(device_t dev)
148 {
149 	struct spi_softc *sc;
150 	uint32_t reg;
151 
152 	sc = device_get_softc(dev);
153 
154 	if (bus_alloc_resources(dev, spi_spec, sc->res)) {
155 		device_printf(dev, "could not allocate resources\n");
156 		return (ENXIO);
157 	}
158 
159 	/* Memory interface */
160 	sc->bst = rman_get_bustag(sc->res[0]);
161 	sc->bsh = rman_get_bushandle(sc->res[0]);
162 
163 	reg = READ4(sc, SPI_MCR);
164 	reg |= MCR_MSTR;
165 	reg &= ~(MCR_CONT_SCKE | MCR_MDIS | MCR_FRZ);
166 	reg &= ~(MCR_PCSIS_M << MCR_PCSIS_S);
167 	reg |= (MCR_PCSIS_M << MCR_PCSIS_S);	/* PCS Active low */
168 	reg |= (MCR_CLR_TXF | MCR_CLR_RXF);
169 	WRITE4(sc, SPI_MCR, reg);
170 
171 	reg = READ4(sc, SPI_RSER);
172 	reg |= RSER_EOQF_RE;
173 	WRITE4(sc, SPI_RSER, reg);
174 
175 	reg = READ4(sc, SPI_MCR);
176 	reg &= ~MCR_HALT;
177 	WRITE4(sc, SPI_MCR, reg);
178 
179 	reg = READ4(sc, SPI_CTAR0);
180 	reg &= ~(CTAR_FMSZ_M << CTAR_FMSZ_S);
181 	reg |= (CTAR_FMSZ_8 << CTAR_FMSZ_S);
182 	/*
183 	 * TODO: calculate BR
184 	 * SCK baud rate = ( fsys / PBR ) * (1 + DBR) / BR
185 	 *
186 	 * reg &= ~(CTAR_BR_M << CTAR_BR_S);
187 	 */
188 	reg &= ~CTAR_CPOL; /* Polarity */
189 	reg |= CTAR_CPHA;
190 	/*
191 	 * Set LSB (Less significant bit first)
192 	 * must be used for some applications, e.g. some LCDs
193 	 */
194 	reg |= CTAR_LSBFE;
195 	WRITE4(sc, SPI_CTAR0, reg);
196 
197 	reg = READ4(sc, SPI_CTAR0);
198 	reg &= ~(CTAR_PBR_M << CTAR_PBR_S);
199 	reg |= (CTAR_PBR_7 << CTAR_PBR_S);
200 	WRITE4(sc, SPI_CTAR0, reg);
201 
202 	device_add_child(dev, "spibus", 0);
203 	return (bus_generic_attach(dev));
204 }
205 
206 static int
207 spi_txrx(struct spi_softc *sc, uint8_t *out_buf,
208     uint8_t *in_buf, int bufsz, int cs)
209 {
210 	uint32_t reg, wreg;
211 	uint32_t txcnt;
212 	uint32_t i;
213 
214 	txcnt = 0;
215 
216 	for (i = 0; i < bufsz; i++) {
217 		txcnt++;
218 		wreg = out_buf[i];
219 		wreg |= PUSHR_CONT;
220 		wreg |= (cs << PUSHR_PCS_S);
221 		if (i == 0)
222 			wreg |= PUSHR_CTCNT;
223 		if (i == (bufsz - 1) || txcnt == SPI_FIFO_SIZE)
224 			wreg |= PUSHR_EOQ;
225 		WRITE4(sc, SPI_PUSHR, wreg);
226 
227 		if (i == (bufsz - 1) || txcnt == SPI_FIFO_SIZE) {
228 			txcnt = 0;
229 
230 			/* Wait last entry in a queue to be transmitted */
231 			while((READ4(sc, SPI_SR) & SR_EOQF) == 0)
232 				continue;
233 
234 			reg = READ4(sc, SPI_SR);
235 			reg |= (SR_TCF | SR_EOQF);
236 			WRITE4(sc, SPI_SR, reg);
237 		}
238 
239 		/* Wait until RX FIFO is empty */
240 		while((READ4(sc, SPI_SR) & SR_RFDF) == 0)
241 			continue;
242 
243 		in_buf[i] = READ1(sc, SPI_POPR);
244 	}
245 
246 	return (0);
247 }
248 
249 static int
250 spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
251 {
252 	struct spi_softc *sc;
253 	uint32_t cs;
254 
255 	sc = device_get_softc(dev);
256 
257 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
258 	    ("%s: TX/RX command sizes should be equal", __func__));
259 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
260 	    ("%s: TX/RX data sizes should be equal", __func__));
261 
262 	/* get the proper chip select */
263 	spibus_get_cs(child, &cs);
264 
265 	cs &= ~SPIBUS_CS_HIGH;
266 
267 	/* Command */
268 	spi_txrx(sc, cmd->tx_cmd, cmd->rx_cmd, cmd->tx_cmd_sz, cs);
269 
270 	/* Data */
271 	spi_txrx(sc, cmd->tx_data, cmd->rx_data, cmd->tx_data_sz, cs);
272 
273 	return (0);
274 }
275 
276 static device_method_t spi_methods[] = {
277 	/* Device interface */
278 	DEVMETHOD(device_probe,		spi_probe),
279 	DEVMETHOD(device_attach,	spi_attach),
280 	/* SPI interface */
281 	DEVMETHOD(spibus_transfer,	spi_transfer),
282 	{ 0, 0 }
283 };
284 
285 static driver_t spi_driver = {
286 	"spi",
287 	spi_methods,
288 	sizeof(struct spi_softc),
289 };
290 
291 static devclass_t spi_devclass;
292 
293 DRIVER_MODULE(spi, simplebus, spi_driver, spi_devclass, 0, 0);
294