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
spi_probe(device_t dev)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
spi_attach(device_t dev)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
spi_txrx(struct spi_softc * sc,uint8_t * out_buf,uint8_t * in_buf,int bufsz,int cs)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
spi_transfer(device_t dev,device_t child,struct spi_command * cmd)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