1 // SPDX-License-Identifier: GPL-2.0+
3 * eSPI controller driver.
5 * Copyright 2010-2011 Freescale Semiconductor, Inc.
6 * Author: Mingkai Hu (Mingkai.hu@freescale.com)
11 #include <linux/delay.h>
15 #include <asm/immap_85xx.h>
17 struct fsl_spi_slave {
18 struct spi_slave slave;
27 unsigned int max_transfer_length;
30 #define to_fsl_spi_slave(s) container_of(s, struct fsl_spi_slave, slave)
31 #define US_PER_SECOND 1000000UL
33 #define ESPI_MAX_CS_NUM 4
34 #define ESPI_FIFO_WIDTH_BIT 32
36 #define ESPI_EV_RNE BIT(9)
37 #define ESPI_EV_TNF BIT(8)
38 #define ESPI_EV_DON BIT(14)
39 #define ESPI_EV_TXE BIT(15)
40 #define ESPI_EV_RFCNT_SHIFT 24
41 #define ESPI_EV_RFCNT_MASK (0x3f << ESPI_EV_RFCNT_SHIFT)
43 #define ESPI_MODE_EN BIT(31) /* Enable interface */
44 #define ESPI_MODE_TXTHR(x) ((x) << 8) /* Tx FIFO threshold */
45 #define ESPI_MODE_RXTHR(x) ((x) << 0) /* Rx FIFO threshold */
47 #define ESPI_COM_CS(x) ((x) << 30)
48 #define ESPI_COM_TRANLEN(x) ((x) << 0)
50 #define ESPI_CSMODE_CI_INACTIVEHIGH BIT(31)
51 #define ESPI_CSMODE_CP_BEGIN_EDGCLK BIT(30)
52 #define ESPI_CSMODE_REV_MSB_FIRST BIT(29)
53 #define ESPI_CSMODE_DIV16 BIT(28)
54 #define ESPI_CSMODE_PM(x) ((x) << 24)
55 #define ESPI_CSMODE_POL_ASSERTED_LOW BIT(20)
56 #define ESPI_CSMODE_LEN(x) ((x) << 16)
57 #define ESPI_CSMODE_CSBEF(x) ((x) << 12)
58 #define ESPI_CSMODE_CSAFT(x) ((x) << 8)
59 #define ESPI_CSMODE_CSCG(x) ((x) << 3)
61 #define ESPI_CSMODE_INIT_VAL (ESPI_CSMODE_POL_ASSERTED_LOW | \
62 ESPI_CSMODE_CSBEF(0) | ESPI_CSMODE_CSAFT(0) | \
65 #define ESPI_MAX_DATA_TRANSFER_LEN 0xFFF0
67 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
68 unsigned int max_hz, unsigned int mode)
70 struct fsl_spi_slave *fsl;
72 unsigned long spibrg = 0;
73 unsigned long spi_freq = 0;
76 if (!spi_cs_is_valid(bus, cs))
79 fsl = spi_alloc_slave(struct fsl_spi_slave, bus, cs);
83 fsl->espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
85 fsl->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN;
87 /* Set eSPI BRG clock source */
88 get_sys_info(&sysinfo);
89 spibrg = sysinfo.freq_systembus / 2;
91 if ((spibrg / max_hz) > 32) {
92 fsl->div16 = ESPI_CSMODE_DIV16;
93 pm = spibrg / (max_hz * 16 * 2);
96 debug("Requested speed is too low: %d Hz, %ld Hz "
97 "is used.\n", max_hz, spibrg / (32 * 16));
100 pm = spibrg / (max_hz * 2);
106 spi_freq = spibrg / ((pm + 1) * 2 * 16);
108 spi_freq = spibrg / ((pm + 1) * 2);
110 /* set tx_timeout to 10 times of one espi FIFO entry go out */
111 fsl->tx_timeout = DIV_ROUND_UP((US_PER_SECOND * ESPI_FIFO_WIDTH_BIT
117 void spi_free_slave(struct spi_slave *slave)
119 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
123 int spi_claim_bus(struct spi_slave *slave)
125 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
126 ccsr_espi_t *espi = fsl->espi;
127 unsigned char pm = fsl->pm;
128 unsigned int cs = slave->cs;
129 unsigned int mode = fsl->mode;
130 unsigned int div16 = fsl->div16;
133 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, cs);
135 /* Enable eSPI interface */
136 out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
137 | ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
139 out_be32(&espi->event, 0xffffffff); /* Clear all eSPI events */
140 out_be32(&espi->mask, 0x00000000); /* Mask all eSPI interrupts */
142 /* Init CS mode interface */
143 for (i = 0; i < ESPI_MAX_CS_NUM; i++)
144 out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
146 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs]) &
147 ~(ESPI_CSMODE_PM(0xF) | ESPI_CSMODE_DIV16
148 | ESPI_CSMODE_CI_INACTIVEHIGH | ESPI_CSMODE_CP_BEGIN_EDGCLK
149 | ESPI_CSMODE_REV_MSB_FIRST | ESPI_CSMODE_LEN(0xF)));
151 /* Set eSPI BRG clock source */
152 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
153 | ESPI_CSMODE_PM(pm) | div16);
157 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
158 | ESPI_CSMODE_CP_BEGIN_EDGCLK);
160 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
161 | ESPI_CSMODE_CI_INACTIVEHIGH);
163 /* Character bit order: msb first */
164 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
165 | ESPI_CSMODE_REV_MSB_FIRST);
167 /* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
168 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
169 | ESPI_CSMODE_LEN(7));
174 void spi_release_bus(struct spi_slave *slave)
179 static void fsl_espi_tx(struct fsl_spi_slave *fsl, const void *dout)
181 ccsr_espi_t *espi = fsl->espi;
182 unsigned int tmpdout, event;
186 tmpdout = *(u32 *)dout;
190 out_be32(&espi->tx, tmpdout);
191 out_be32(&espi->event, ESPI_EV_TNF);
192 debug("***spi_xfer:...%08x written\n", tmpdout);
194 tmp_tx_timeout = fsl->tx_timeout;
195 /* Wait for eSPI transmit to go out */
196 while (tmp_tx_timeout--) {
197 event = in_be32(&espi->event);
198 if (event & ESPI_EV_DON || event & ESPI_EV_TXE) {
199 out_be32(&espi->event, ESPI_EV_TXE);
205 if (tmp_tx_timeout < 0)
206 debug("***spi_xfer:...Tx timeout! event = %08x\n", event);
209 static int fsl_espi_rx(struct fsl_spi_slave *fsl, void *din, unsigned int bytes)
211 ccsr_espi_t *espi = fsl->espi;
212 unsigned int tmpdin, rx_times;
213 unsigned char *buf, *p_cursor;
218 rx_times = DIV_ROUND_UP(bytes, 4);
219 buf = (unsigned char *)malloc(4 * rx_times);
221 debug("SF: Failed to malloc memory.\n");
226 tmpdin = in_be32(&espi->rx);
227 debug("***spi_xfer:...%08x readed\n", tmpdin);
228 *(u32 *)p_cursor = tmpdin;
233 memcpy(din, buf, bytes);
236 out_be32(&espi->event, ESPI_EV_RNE);
241 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
242 void *data_in, unsigned long flags)
244 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
245 ccsr_espi_t *espi = fsl->espi;
246 unsigned int event, rx_bytes;
247 const void *dout = NULL;
250 int num_blks, num_chunks, max_tran_len, tran_len;
252 unsigned char *buffer = NULL;
254 u8 *cmd_buf = fsl->cmd_buf;
255 size_t cmd_len = fsl->cmd_len;
256 size_t data_len = bitlen / 8;
257 size_t rx_offset = 0;
260 max_tran_len = fsl->max_transfer_length;
263 cmd_len = fsl->cmd_len = data_len;
264 memcpy(cmd_buf, data_out, cmd_len);
269 spi_cs_deactivate(slave);
272 buf_len = 2 * cmd_len + min(data_len, (size_t)max_tran_len);
273 len = cmd_len + data_len;
275 buffer = (unsigned char *)malloc(buf_len);
277 debug("SF: Failed to malloc memory.\n");
280 memcpy(buffer, cmd_buf, cmd_len);
282 memcpy(buffer + cmd_len, data_out, data_len);
284 case SPI_XFER_BEGIN | SPI_XFER_END:
286 buffer = (unsigned char *)malloc(len * 2);
288 debug("SF: Failed to malloc memory.\n");
291 memcpy(buffer, data_out, len);
297 debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) len %u\n",
298 *(uint *)data_out, data_out, *(uint *)data_in, data_in, len);
300 num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
301 while (num_chunks--) {
303 din = buffer + rx_offset;
305 tran_len = min(data_len, (size_t)max_tran_len);
306 num_blks = DIV_ROUND_UP(tran_len + cmd_len, 4);
307 num_bytes = (tran_len + cmd_len) % 4;
308 fsl->data_len = tran_len + cmd_len;
309 spi_cs_activate(slave);
311 /* Clear all eSPI events */
312 out_be32(&espi->event , 0xffffffff);
313 /* handle data in 32-bit chunks */
315 event = in_be32(&espi->event);
316 if (event & ESPI_EV_TNF) {
317 fsl_espi_tx(fsl, dout);
318 /* Set up the next iteration */
325 event = in_be32(&espi->event);
326 if (event & ESPI_EV_RNE) {
327 rf_cnt = ((event & ESPI_EV_RFCNT_MASK)
328 >> ESPI_EV_RFCNT_SHIFT);
331 else if (num_blks == 1 && rf_cnt == num_bytes)
332 rx_bytes = num_bytes;
335 if (fsl_espi_rx(fsl, din, rx_bytes)
339 din = (unsigned char *)din
345 memcpy(data_in, buffer + 2 * cmd_len, tran_len);
346 if (*buffer == 0x0b) {
348 data_len -= tran_len;
349 *(int *)buffer += tran_len;
352 spi_cs_deactivate(slave);
359 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
361 return bus == 0 && cs < ESPI_MAX_CS_NUM;
364 void spi_cs_activate(struct spi_slave *slave)
366 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
367 ccsr_espi_t *espi = fsl->espi;
368 unsigned int com = 0;
369 size_t data_len = fsl->data_len;
371 com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
372 com |= ESPI_COM_CS(slave->cs);
373 com |= ESPI_COM_TRANLEN(data_len - 1);
374 out_be32(&espi->com, com);
377 void spi_cs_deactivate(struct spi_slave *slave)
379 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
380 ccsr_espi_t *espi = fsl->espi;
382 /* clear the RXCNT and TXCNT */
383 out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN));
384 out_be32(&espi->mode, in_be32(&espi->mode) | ESPI_MODE_EN);