xref: /freebsd/sys/arm/freescale/vybrid/vf_spi.c (revision 6ae1554a5d9b318f8ad53ccc39fa5a961403da73)
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/fdt/fdt_common.h>
52 #include <dev/ofw/openfirm.h>
53 #include <dev/ofw/ofw_bus.h>
54 #include <dev/ofw/ofw_bus_subr.h>
55 
56 #include <machine/bus.h>
57 #include <machine/cpu.h>
58 #include <machine/intr.h>
59 
60 #include <arm/freescale/vybrid/vf_common.h>
61 
62 #define	SPI_FIFO_SIZE	4
63 
64 #define	SPI_MCR		0x00		/* Module Configuration */
65 #define	 MCR_MSTR	(1 << 31)	/* Master/Slave Mode Select */
66 #define	 MCR_CONT_SCKE	(1 << 30)	/* Continuous SCK Enable */
67 #define	 MCR_FRZ	(1 << 27)	/* Freeze */
68 #define	 MCR_PCSIS_S	16		/* Peripheral Chip Select */
69 #define	 MCR_PCSIS_M	0x3f
70 #define	 MCR_MDIS	(1 << 14)	/* Module Disable */
71 #define	 MCR_CLR_TXF	(1 << 11)	/* Clear TX FIFO */
72 #define	 MCR_CLR_RXF	(1 << 10)	/* Clear RX FIFO */
73 #define	 MCR_HALT	(1 << 0)	/* Starts and stops SPI transfers */
74 #define	SPI_TCR		0x08		/* Transfer Count */
75 #define	SPI_CTAR0	0x0C		/* Clock and Transfer Attributes */
76 #define	SPI_CTAR0_SLAVE	0x0C		/* Clock and Transfer Attributes */
77 #define	SPI_CTAR1	0x10		/* Clock and Transfer Attributes */
78 #define	SPI_CTAR2	0x14		/* Clock and Transfer Attributes */
79 #define	SPI_CTAR3	0x18		/* Clock and Transfer Attributes */
80 #define	 CTAR_FMSZ_M	0xf
81 #define	 CTAR_FMSZ_S	27		/* Frame Size */
82 #define	 CTAR_FMSZ_8	0x7		/* 8 bits */
83 #define	 CTAR_CPOL	(1 << 26)	/* Clock Polarity */
84 #define	 CTAR_CPHA	(1 << 25)	/* Clock Phase */
85 #define	 CTAR_LSBFE	(1 << 24)	/* Less significant bit first */
86 #define	 CTAR_PCSSCK_M	0x3
87 #define	 CTAR_PCSSCK_S	22		/* PCS to SCK Delay Prescaler */
88 #define	 CTAR_PBR_M	0x3
89 #define	 CTAR_PBR_S	16		/* Baud Rate Prescaler */
90 #define	 CTAR_PBR_7	0x3		/* Divide by 7 */
91 #define	 CTAR_CSSCK_M	0xf
92 #define	 CTAR_CSSCK_S	12		/* PCS to SCK Delay Scaler */
93 #define	 CTAR_BR_M	0xf
94 #define	 CTAR_BR_S	0		/* Baud Rate Scaler */
95 #define	SPI_SR		0x2C		/* Status Register */
96 #define	 SR_TCF		(1 << 31)	/* Transfer Complete Flag */
97 #define	 SR_EOQF	(1 << 28)	/* End of Queue Flag */
98 #define	 SR_TFFF	(1 << 25)	/* Transmit FIFO Fill Flag */
99 #define	 SR_RFDF	(1 << 17)	/* Receive FIFO Drain Flag */
100 #define	SPI_RSER	0x30		/* DMA/Interrupt Select */
101 #define	 RSER_EOQF_RE	(1 << 28)	/* Finished Request Enable */
102 #define	SPI_PUSHR	0x34		/* PUSH TX FIFO In Master Mode */
103 #define	 PUSHR_CONT	(1 << 31)	/* Continuous Peripheral CS */
104 #define	 PUSHR_EOQ	(1 << 27)	/* End Of Queue */
105 #define	 PUSHR_CTCNT	(1 << 26)	/* Clear Transfer Counter */
106 #define	 PUSHR_PCS_M	0x3f
107 #define	 PUSHR_PCS_S	16		/* Select PCS signals */
108 
109 #define	SPI_PUSHR_SLAVE	0x34	/* PUSH TX FIFO Register In Slave Mode */
110 #define	SPI_POPR	0x38	/* POP RX FIFO Register */
111 #define	SPI_TXFR0	0x3C	/* Transmit FIFO Registers */
112 #define	SPI_TXFR1	0x40
113 #define	SPI_TXFR2	0x44
114 #define	SPI_TXFR3	0x48
115 #define	SPI_RXFR0	0x7C	/* Receive FIFO Registers */
116 #define	SPI_RXFR1	0x80
117 #define	SPI_RXFR2	0x84
118 #define	SPI_RXFR3	0x88
119 
120 struct spi_softc {
121 	struct resource		*res[2];
122 	bus_space_tag_t		bst;
123 	bus_space_handle_t	bsh;
124 	void			*ih;
125 };
126 
127 static struct resource_spec spi_spec[] = {
128 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
129 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
130 	{ -1, 0 }
131 };
132 
133 static int
134 spi_probe(device_t dev)
135 {
136 
137 	if (!ofw_bus_status_okay(dev))
138 		return (ENXIO);
139 
140 	if (!ofw_bus_is_compatible(dev, "fsl,mvf600-spi"))
141 		return (ENXIO);
142 
143 	device_set_desc(dev, "Vybrid Family Serial Peripheral Interface");
144 	return (BUS_PROBE_DEFAULT);
145 }
146 
147 static int
148 spi_attach(device_t dev)
149 {
150 	struct spi_softc *sc;
151 	uint32_t reg;
152 
153 	sc = device_get_softc(dev);
154 
155 	if (bus_alloc_resources(dev, spi_spec, sc->res)) {
156 		device_printf(dev, "could not allocate resources\n");
157 		return (ENXIO);
158 	}
159 
160 	/* Memory interface */
161 	sc->bst = rman_get_bustag(sc->res[0]);
162 	sc->bsh = rman_get_bushandle(sc->res[0]);
163 
164 	reg = READ4(sc, SPI_MCR);
165 	reg |= MCR_MSTR;
166 	reg &= ~(MCR_CONT_SCKE | MCR_MDIS | MCR_FRZ);
167 	reg &= ~(MCR_PCSIS_M << MCR_PCSIS_S);
168 	reg |= (MCR_PCSIS_M << MCR_PCSIS_S);	/* PCS Active low */
169 	reg |= (MCR_CLR_TXF | MCR_CLR_RXF);
170 	WRITE4(sc, SPI_MCR, reg);
171 
172 	reg = READ4(sc, SPI_RSER);
173 	reg |= RSER_EOQF_RE;
174 	WRITE4(sc, SPI_RSER, reg);
175 
176 	reg = READ4(sc, SPI_MCR);
177 	reg &= ~MCR_HALT;
178 	WRITE4(sc, SPI_MCR, reg);
179 
180 	reg = READ4(sc, SPI_CTAR0);
181 	reg &= ~(CTAR_FMSZ_M << CTAR_FMSZ_S);
182 	reg |= (CTAR_FMSZ_8 << CTAR_FMSZ_S);
183 	/*
184 	 * TODO: calculate BR
185 	 * SCK baud rate = ( fsys / PBR ) * (1 + DBR) / BR
186 	 *
187 	 * reg &= ~(CTAR_BR_M << CTAR_BR_S);
188 	 */
189 	reg &= ~CTAR_CPOL; /* Polarity */
190 	reg |= CTAR_CPHA;
191 	/*
192 	 * Set LSB (Less significant bit first)
193 	 * must be used for some applications, e.g. some LCDs
194 	 */
195 	reg |= CTAR_LSBFE;
196 	WRITE4(sc, SPI_CTAR0, reg);
197 
198 	reg = READ4(sc, SPI_CTAR0);
199 	reg &= ~(CTAR_PBR_M << CTAR_PBR_S);
200 	reg |= (CTAR_PBR_7 << CTAR_PBR_S);
201 	WRITE4(sc, SPI_CTAR0, reg);
202 
203 	device_add_child(dev, "spibus", 0);
204 	return (bus_generic_attach(dev));
205 }
206 
207 static int
208 spi_txrx(struct spi_softc *sc, uint8_t *out_buf,
209     uint8_t *in_buf, int bufsz, int cs)
210 {
211 	uint32_t reg, wreg;
212 	uint32_t txcnt;
213 	uint32_t i;
214 
215 	txcnt = 0;
216 
217 	for (i = 0; i < bufsz; i++) {
218 		txcnt++;
219 		wreg = out_buf[i];
220 		wreg |= PUSHR_CONT;
221 		wreg |= (cs << PUSHR_PCS_S);
222 		if (i == 0)
223 			wreg |= PUSHR_CTCNT;
224 		if (i == (bufsz - 1) || txcnt == SPI_FIFO_SIZE)
225 			wreg |= PUSHR_EOQ;
226 		WRITE4(sc, SPI_PUSHR, wreg);
227 
228 		if (i == (bufsz - 1) || txcnt == SPI_FIFO_SIZE) {
229 			txcnt = 0;
230 
231 			/* Wait last entry in a queue to be transmitted */
232 			while((READ4(sc, SPI_SR) & SR_EOQF) == 0)
233 				continue;
234 
235 			reg = READ4(sc, SPI_SR);
236 			reg |= (SR_TCF | SR_EOQF);
237 			WRITE4(sc, SPI_SR, reg);
238 		}
239 
240 		/* Wait until RX FIFO is empty */
241 		while((READ4(sc, SPI_SR) & SR_RFDF) == 0)
242 			continue;
243 
244 		in_buf[i] = READ1(sc, SPI_POPR);
245 	}
246 
247 	return (0);
248 }
249 
250 static int
251 spi_transfer(device_t dev, device_t child, struct spi_command *cmd)
252 {
253 	struct spi_softc *sc;
254 	uint32_t cs;
255 
256 	sc = device_get_softc(dev);
257 
258 	KASSERT(cmd->tx_cmd_sz == cmd->rx_cmd_sz,
259 	    ("%s: TX/RX command sizes should be equal", __func__));
260 	KASSERT(cmd->tx_data_sz == cmd->rx_data_sz,
261 	    ("%s: TX/RX data sizes should be equal", __func__));
262 
263 	/* get the proper chip select */
264 	spibus_get_cs(child, &cs);
265 
266 	/* Command */
267 	spi_txrx(sc, cmd->tx_cmd, cmd->rx_cmd, cmd->tx_cmd_sz, cs);
268 
269 	/* Data */
270 	spi_txrx(sc, cmd->tx_data, cmd->rx_data, cmd->tx_data_sz, cs);
271 
272 	return (0);
273 }
274 
275 static device_method_t spi_methods[] = {
276 	/* Device interface */
277 	DEVMETHOD(device_probe,		spi_probe),
278 	DEVMETHOD(device_attach,	spi_attach),
279 	/* SPI interface */
280 	DEVMETHOD(spibus_transfer,	spi_transfer),
281 	{ 0, 0 }
282 };
283 
284 static driver_t spi_driver = {
285 	"spi",
286 	spi_methods,
287 	sizeof(struct spi_softc),
288 };
289 
290 static devclass_t spi_devclass;
291 
292 DRIVER_MODULE(spi, simplebus, spi_driver, spi_devclass, 0, 0);
293