xref: /openbmc/u-boot/drivers/spi/fsl_espi.c (revision 7ca6f363)
1 /*
2  * eSPI controller driver.
3  *
4  * Copyright 2010-2011 Freescale Semiconductor, Inc.
5  * Author: Mingkai Hu (Mingkai.hu@freescale.com)
6  *
7  * SPDX-License-Identifier:	GPL-2.0+
8  */
9 
10 #include <common.h>
11 
12 #include <malloc.h>
13 #include <spi.h>
14 #include <asm/immap_85xx.h>
15 
16 struct fsl_spi_slave {
17 	struct spi_slave slave;
18 	unsigned int	div16;
19 	unsigned int	pm;
20 	unsigned int	mode;
21 	size_t		cmd_len;
22 	u8		cmd_buf[16];
23 	size_t		data_len;
24 	unsigned int    max_transfer_length;
25 };
26 
27 #define to_fsl_spi_slave(s) container_of(s, struct fsl_spi_slave, slave)
28 
29 #define ESPI_MAX_CS_NUM		4
30 
31 #define ESPI_EV_RNE		(1 << 9)
32 #define ESPI_EV_TNF		(1 << 8)
33 
34 #define ESPI_MODE_EN		(1 << 31)	/* Enable interface */
35 #define ESPI_MODE_TXTHR(x)	((x) << 8)	/* Tx FIFO threshold */
36 #define ESPI_MODE_RXTHR(x)	((x) << 0)	/* Rx FIFO threshold */
37 
38 #define ESPI_COM_CS(x)		((x) << 30)
39 #define ESPI_COM_TRANLEN(x)	((x) << 0)
40 
41 #define ESPI_CSMODE_CI_INACTIVEHIGH	(1 << 31)
42 #define ESPI_CSMODE_CP_BEGIN_EDGCLK	(1 << 30)
43 #define ESPI_CSMODE_REV_MSB_FIRST	(1 << 29)
44 #define ESPI_CSMODE_DIV16		(1 << 28)
45 #define ESPI_CSMODE_PM(x)		((x) << 24)
46 #define ESPI_CSMODE_POL_ASSERTED_LOW	(1 << 20)
47 #define ESPI_CSMODE_LEN(x)		((x) << 16)
48 #define ESPI_CSMODE_CSBEF(x)		((x) << 12)
49 #define ESPI_CSMODE_CSAFT(x)		((x) << 8)
50 #define ESPI_CSMODE_CSCG(x)		((x) << 3)
51 
52 #define ESPI_CSMODE_INIT_VAL (ESPI_CSMODE_POL_ASSERTED_LOW | \
53 		ESPI_CSMODE_CSBEF(0) | ESPI_CSMODE_CSAFT(0) | \
54 		ESPI_CSMODE_CSCG(1))
55 
56 #define ESPI_MAX_DATA_TRANSFER_LEN 0xFFF0
57 
58 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
59 		unsigned int max_hz, unsigned int mode)
60 {
61 	struct fsl_spi_slave *fsl;
62 	sys_info_t sysinfo;
63 	unsigned long spibrg = 0;
64 	unsigned char pm = 0;
65 
66 	if (!spi_cs_is_valid(bus, cs))
67 		return NULL;
68 
69 	fsl = spi_alloc_slave(struct fsl_spi_slave, bus, cs);
70 	if (!fsl)
71 		return NULL;
72 
73 	fsl->mode = mode;
74 	fsl->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN;
75 
76 	/* Set eSPI BRG clock source */
77 	get_sys_info(&sysinfo);
78 	spibrg = sysinfo.freq_systembus / 2;
79 	fsl->div16 = 0;
80 	if ((spibrg / max_hz) > 32) {
81 		fsl->div16 = ESPI_CSMODE_DIV16;
82 		pm = spibrg / (max_hz * 16 * 2);
83 		if (pm > 16) {
84 			pm = 16;
85 			debug("Requested speed is too low: %d Hz, %ld Hz "
86 				"is used.\n", max_hz, spibrg / (32 * 16));
87 		}
88 	} else
89 		pm = spibrg / (max_hz * 2);
90 	if (pm)
91 		pm--;
92 	fsl->pm = pm;
93 
94 	return &fsl->slave;
95 }
96 
97 void spi_free_slave(struct spi_slave *slave)
98 {
99 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
100 	free(fsl);
101 }
102 
103 void spi_init(void)
104 {
105 
106 }
107 
108 int spi_claim_bus(struct spi_slave *slave)
109 {
110 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
111 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
112 	unsigned char pm = fsl->pm;
113 	unsigned int cs = slave->cs;
114 	unsigned int mode =  fsl->mode;
115 	unsigned int div16 = fsl->div16;
116 	int i;
117 
118 	debug("%s: bus:%i cs:%i\n", __func__, slave->bus, cs);
119 
120 	/* Enable eSPI interface */
121 	out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
122 			| ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
123 
124 	out_be32(&espi->event, 0xffffffff); /* Clear all eSPI events */
125 	out_be32(&espi->mask, 0x00000000); /* Mask  all eSPI interrupts */
126 
127 	/* Init CS mode interface */
128 	for (i = 0; i < ESPI_MAX_CS_NUM; i++)
129 		out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
130 
131 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs]) &
132 		~(ESPI_CSMODE_PM(0xF) | ESPI_CSMODE_DIV16
133 		| ESPI_CSMODE_CI_INACTIVEHIGH | ESPI_CSMODE_CP_BEGIN_EDGCLK
134 		| ESPI_CSMODE_REV_MSB_FIRST | ESPI_CSMODE_LEN(0xF)));
135 
136 	/* Set eSPI BRG clock source */
137 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
138 		| ESPI_CSMODE_PM(pm) | div16);
139 
140 	/* Set eSPI mode */
141 	if (mode & SPI_CPHA)
142 		out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
143 			| ESPI_CSMODE_CP_BEGIN_EDGCLK);
144 	if (mode & SPI_CPOL)
145 		out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
146 			| ESPI_CSMODE_CI_INACTIVEHIGH);
147 
148 	/* Character bit order: msb first */
149 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
150 		| ESPI_CSMODE_REV_MSB_FIRST);
151 
152 	/* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
153 	out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
154 		| ESPI_CSMODE_LEN(7));
155 
156 	return 0;
157 }
158 
159 void spi_release_bus(struct spi_slave *slave)
160 {
161 
162 }
163 
164 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
165 		void *data_in, unsigned long flags)
166 {
167 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
168 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
169 	unsigned int tmpdout, tmpdin, event;
170 	const void *dout = NULL;
171 	void *din = NULL;
172 	int len = 0;
173 	int num_blks, num_chunks, max_tran_len, tran_len;
174 	int num_bytes;
175 	unsigned char *ch;
176 	unsigned char *buffer = NULL;
177 	size_t buf_len;
178 	u8 *cmd_buf = fsl->cmd_buf;
179 	size_t cmd_len = fsl->cmd_len;
180 	size_t data_len = bitlen / 8;
181 	size_t rx_offset = 0;
182 
183 	max_tran_len = fsl->max_transfer_length;
184 	switch (flags) {
185 	case SPI_XFER_BEGIN:
186 		cmd_len = fsl->cmd_len = data_len;
187 		memcpy(cmd_buf, data_out, cmd_len);
188 		return 0;
189 	case 0:
190 	case SPI_XFER_END:
191 		if (bitlen == 0) {
192 			spi_cs_deactivate(slave);
193 			return 0;
194 		}
195 		buf_len = 2 * cmd_len + min(data_len, max_tran_len);
196 		len = cmd_len + data_len;
197 		rx_offset = cmd_len;
198 		buffer = (unsigned char *)malloc(buf_len);
199 		if (!buffer) {
200 			debug("SF: Failed to malloc memory.\n");
201 			return 1;
202 		}
203 		memcpy(buffer, cmd_buf, cmd_len);
204 		if (data_in == NULL)
205 			memcpy(buffer + cmd_len, data_out, data_len);
206 		break;
207 	case SPI_XFER_BEGIN | SPI_XFER_END:
208 		len = data_len;
209 		buffer = (unsigned char *)malloc(len * 2);
210 		if (!buffer) {
211 			debug("SF: Failed to malloc memory.\n");
212 			return 1;
213 		}
214 		memcpy(buffer, data_out, len);
215 		rx_offset = len;
216 		cmd_len = 0;
217 		break;
218 	}
219 
220 	debug("spi_xfer: slave %u:%u dout %08X(%p) din %08X(%p) len %u\n",
221 	      slave->bus, slave->cs, *(uint *) dout,
222 	      dout, *(uint *) din, din, len);
223 
224 	num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
225 	while (num_chunks--) {
226 		if (data_in)
227 			din = buffer + rx_offset;
228 		dout = buffer;
229 		tran_len = min(data_len , max_tran_len);
230 		num_blks = DIV_ROUND_UP(tran_len + cmd_len, 4);
231 		num_bytes = (tran_len + cmd_len) % 4;
232 		fsl->data_len = tran_len + cmd_len;
233 		spi_cs_activate(slave);
234 
235 		/* Clear all eSPI events */
236 		out_be32(&espi->event , 0xffffffff);
237 		/* handle data in 32-bit chunks */
238 		while (num_blks--) {
239 
240 			event = in_be32(&espi->event);
241 			if (event & ESPI_EV_TNF) {
242 				tmpdout = *(u32 *)dout;
243 
244 				/* Set up the next iteration */
245 				if (len > 4) {
246 					len -= 4;
247 					dout += 4;
248 				}
249 
250 				out_be32(&espi->tx, tmpdout);
251 				out_be32(&espi->event, ESPI_EV_TNF);
252 				debug("***spi_xfer:...%08x written\n", tmpdout);
253 			}
254 
255 			/* Wait for eSPI transmit to get out */
256 			udelay(80);
257 
258 			event = in_be32(&espi->event);
259 			if (event & ESPI_EV_RNE) {
260 				tmpdin = in_be32(&espi->rx);
261 				if (num_blks == 0 && num_bytes != 0) {
262 					ch = (unsigned char *)&tmpdin;
263 					while (num_bytes--)
264 						*(unsigned char *)din++ = *ch++;
265 				} else {
266 					*(u32 *) din = tmpdin;
267 					din += 4;
268 				}
269 
270 				out_be32(&espi->event, in_be32(&espi->event)
271 						| ESPI_EV_RNE);
272 				debug("***spi_xfer:...%08x readed\n", tmpdin);
273 			}
274 		}
275 		if (data_in) {
276 			memcpy(data_in, buffer + 2 * cmd_len, tran_len);
277 			if (*buffer == 0x0b) {
278 				data_in += tran_len;
279 				data_len -= tran_len;
280 				*(int *)buffer += tran_len;
281 			}
282 		}
283 		spi_cs_deactivate(slave);
284 	}
285 
286 	free(buffer);
287 	return 0;
288 }
289 
290 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
291 {
292 	return bus == 0 && cs < ESPI_MAX_CS_NUM;
293 }
294 
295 void spi_cs_activate(struct spi_slave *slave)
296 {
297 	struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
298 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
299 	unsigned int com = 0;
300 	size_t data_len = fsl->data_len;
301 
302 	com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
303 	com |= ESPI_COM_CS(slave->cs);
304 	com |= ESPI_COM_TRANLEN(data_len - 1);
305 	out_be32(&espi->com, com);
306 }
307 
308 void spi_cs_deactivate(struct spi_slave *slave)
309 {
310 	ccsr_espi_t *espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
311 
312 	/* clear the RXCNT and TXCNT */
313 	out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN));
314 	out_be32(&espi->mode, in_be32(&espi->mode) | ESPI_MODE_EN);
315 }
316