xref: /openbmc/u-boot/drivers/spi/sh_qspi.c (revision 8ee59472)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * SH QSPI (Quad SPI) driver
4  *
5  * Copyright (C) 2013 Renesas Electronics Corporation
6  * Copyright (C) 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
7  */
8 
9 #include <common.h>
10 #include <console.h>
11 #include <malloc.h>
12 #include <spi.h>
13 #include <wait_bit.h>
14 #include <asm/arch/rmobile.h>
15 #include <asm/io.h>
16 
17 /* SH QSPI register bit masks <REG>_<BIT> */
18 #define SPCR_MSTR	0x08
19 #define SPCR_SPE	0x40
20 #define SPSR_SPRFF	0x80
21 #define SPSR_SPTEF	0x20
22 #define SPPCR_IO3FV	0x04
23 #define SPPCR_IO2FV	0x02
24 #define SPPCR_IO1FV	0x01
25 #define SPBDCR_RXBC0	BIT(0)
26 #define SPCMD_SCKDEN	BIT(15)
27 #define SPCMD_SLNDEN	BIT(14)
28 #define SPCMD_SPNDEN	BIT(13)
29 #define SPCMD_SSLKP	BIT(7)
30 #define SPCMD_BRDV0	BIT(2)
31 #define SPCMD_INIT1	SPCMD_SCKDEN | SPCMD_SLNDEN | \
32 			SPCMD_SPNDEN | SPCMD_SSLKP | \
33 			SPCMD_BRDV0
34 #define SPCMD_INIT2	SPCMD_SPNDEN | SPCMD_SSLKP | \
35 			SPCMD_BRDV0
36 #define SPBFCR_TXRST	BIT(7)
37 #define SPBFCR_RXRST	BIT(6)
38 #define SPBFCR_TXTRG	0x30
39 #define SPBFCR_RXTRG	0x07
40 
41 /* SH QSPI register set */
42 struct sh_qspi_regs {
43 	u8	spcr;
44 	u8	sslp;
45 	u8	sppcr;
46 	u8	spsr;
47 	u32	spdr;
48 	u8	spscr;
49 	u8	spssr;
50 	u8	spbr;
51 	u8	spdcr;
52 	u8	spckd;
53 	u8	sslnd;
54 	u8	spnd;
55 	u8	dummy0;
56 	u16	spcmd0;
57 	u16	spcmd1;
58 	u16	spcmd2;
59 	u16	spcmd3;
60 	u8	spbfcr;
61 	u8	dummy1;
62 	u16	spbdcr;
63 	u32	spbmul0;
64 	u32	spbmul1;
65 	u32	spbmul2;
66 	u32	spbmul3;
67 };
68 
69 struct sh_qspi_slave {
70 	struct spi_slave	slave;
71 	struct sh_qspi_regs	*regs;
72 };
73 
74 static inline struct sh_qspi_slave *to_sh_qspi(struct spi_slave *slave)
75 {
76 	return container_of(slave, struct sh_qspi_slave, slave);
77 }
78 
79 static void sh_qspi_init(struct sh_qspi_slave *ss)
80 {
81 	/* QSPI initialize */
82 	/* Set master mode only */
83 	writeb(SPCR_MSTR, &ss->regs->spcr);
84 
85 	/* Set SSL signal level */
86 	writeb(0x00, &ss->regs->sslp);
87 
88 	/* Set MOSI signal value when transfer is in idle state */
89 	writeb(SPPCR_IO3FV|SPPCR_IO2FV, &ss->regs->sppcr);
90 
91 	/* Set bit rate. See 58.3.8 Quad Serial Peripheral Interface */
92 	writeb(0x01, &ss->regs->spbr);
93 
94 	/* Disable Dummy Data Transmission */
95 	writeb(0x00, &ss->regs->spdcr);
96 
97 	/* Set clock delay value */
98 	writeb(0x00, &ss->regs->spckd);
99 
100 	/* Set SSL negation delay value */
101 	writeb(0x00, &ss->regs->sslnd);
102 
103 	/* Set next-access delay value */
104 	writeb(0x00, &ss->regs->spnd);
105 
106 	/* Set equence command */
107 	writew(SPCMD_INIT2, &ss->regs->spcmd0);
108 
109 	/* Reset transfer and receive Buffer */
110 	setbits_8(&ss->regs->spbfcr, SPBFCR_TXRST|SPBFCR_RXRST);
111 
112 	/* Clear transfer and receive Buffer control bit */
113 	clrbits_8(&ss->regs->spbfcr, SPBFCR_TXRST|SPBFCR_RXRST);
114 
115 	/* Set equence control method. Use equence0 only */
116 	writeb(0x00, &ss->regs->spscr);
117 
118 	/* Enable SPI function */
119 	setbits_8(&ss->regs->spcr, SPCR_SPE);
120 }
121 
122 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
123 {
124 	return 1;
125 }
126 
127 void spi_cs_activate(struct spi_slave *slave)
128 {
129 	struct sh_qspi_slave *ss = to_sh_qspi(slave);
130 
131 	/* Set master mode only */
132 	writeb(SPCR_MSTR, &ss->regs->spcr);
133 
134 	/* Set command */
135 	writew(SPCMD_INIT1, &ss->regs->spcmd0);
136 
137 	/* Reset transfer and receive Buffer */
138 	setbits_8(&ss->regs->spbfcr, SPBFCR_TXRST|SPBFCR_RXRST);
139 
140 	/* Clear transfer and receive Buffer control bit */
141 	clrbits_8(&ss->regs->spbfcr, SPBFCR_TXRST|SPBFCR_RXRST);
142 
143 	/* Set equence control method. Use equence0 only */
144 	writeb(0x00, &ss->regs->spscr);
145 
146 	/* Enable SPI function */
147 	setbits_8(&ss->regs->spcr, SPCR_SPE);
148 }
149 
150 void spi_cs_deactivate(struct spi_slave *slave)
151 {
152 	struct sh_qspi_slave *ss = to_sh_qspi(slave);
153 
154 	/* Disable SPI Function */
155 	clrbits_8(&ss->regs->spcr, SPCR_SPE);
156 }
157 
158 void spi_init(void)
159 {
160 	/* nothing to do */
161 }
162 
163 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
164 		unsigned int max_hz, unsigned int mode)
165 {
166 	struct sh_qspi_slave *ss;
167 
168 	if (!spi_cs_is_valid(bus, cs))
169 		return NULL;
170 
171 	ss = spi_alloc_slave(struct sh_qspi_slave, bus, cs);
172 	if (!ss) {
173 		printf("SPI_error: Fail to allocate sh_qspi_slave\n");
174 		return NULL;
175 	}
176 
177 	ss->regs = (struct sh_qspi_regs *)SH_QSPI_BASE;
178 
179 	/* Init SH QSPI */
180 	sh_qspi_init(ss);
181 
182 	return &ss->slave;
183 }
184 
185 void spi_free_slave(struct spi_slave *slave)
186 {
187 	struct sh_qspi_slave *spi = to_sh_qspi(slave);
188 
189 	free(spi);
190 }
191 
192 int spi_claim_bus(struct spi_slave *slave)
193 {
194 	return 0;
195 }
196 
197 void spi_release_bus(struct spi_slave *slave)
198 {
199 }
200 
201 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
202 	     void *din, unsigned long flags)
203 {
204 	struct sh_qspi_slave *ss = to_sh_qspi(slave);
205 	u32 nbyte, chunk;
206 	int i, ret = 0;
207 	u8 dtdata = 0, drdata;
208 	u8 *tdata = &dtdata, *rdata = &drdata;
209 	u32 *spbmul0 = &ss->regs->spbmul0;
210 
211 	if (dout == NULL && din == NULL) {
212 		if (flags & SPI_XFER_END)
213 			spi_cs_deactivate(slave);
214 		return 0;
215 	}
216 
217 	if (bitlen % 8) {
218 		printf("%s: bitlen is not 8bit alined %d", __func__, bitlen);
219 		return 1;
220 	}
221 
222 	nbyte = bitlen / 8;
223 
224 	if (flags & SPI_XFER_BEGIN) {
225 		spi_cs_activate(slave);
226 
227 		/* Set 1048576 byte */
228 		writel(0x100000, spbmul0);
229 	}
230 
231 	if (flags & SPI_XFER_END)
232 		writel(nbyte, spbmul0);
233 
234 	if (dout != NULL)
235 		tdata = (u8 *)dout;
236 
237 	if (din != NULL)
238 		rdata = din;
239 
240 	while (nbyte > 0) {
241 		/*
242 		 * Check if there is 32 Byte chunk and if there is, transfer
243 		 * it in one burst, otherwise transfer on byte-by-byte basis.
244 		 */
245 		chunk = (nbyte >= 32) ? 32 : 1;
246 
247 		clrsetbits_8(&ss->regs->spbfcr, SPBFCR_TXTRG | SPBFCR_RXTRG,
248 			     chunk == 32 ? SPBFCR_TXTRG | SPBFCR_RXTRG : 0);
249 
250 		ret = wait_for_bit_8(&ss->regs->spsr, SPSR_SPTEF,
251 				     true, 1000, true);
252 		if (ret)
253 			return ret;
254 
255 		for (i = 0; i < chunk; i++) {
256 			writeb(*tdata, &ss->regs->spdr);
257 			if (dout != NULL)
258 				tdata++;
259 		}
260 
261 		ret = wait_for_bit_8(&ss->regs->spsr, SPSR_SPRFF,
262 				     true, 1000, true);
263 		if (ret)
264 			return ret;
265 
266 		for (i = 0; i < chunk; i++) {
267 			*rdata = readb(&ss->regs->spdr);
268 			if (din != NULL)
269 				rdata++;
270 		}
271 
272 		nbyte -= chunk;
273 	}
274 
275 	if (flags & SPI_XFER_END)
276 		spi_cs_deactivate(slave);
277 
278 	return ret;
279 }
280