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/bitops.h>
12 #include <linux/delay.h>
16 #include <asm/immap_85xx.h>
18 struct fsl_spi_slave {
19 struct spi_slave slave;
28 unsigned int max_transfer_length;
31 #define to_fsl_spi_slave(s) container_of(s, struct fsl_spi_slave, slave)
32 #define US_PER_SECOND 1000000UL
34 #define ESPI_MAX_CS_NUM 4
35 #define ESPI_FIFO_WIDTH_BIT 32
37 #define ESPI_EV_RNE BIT(9)
38 #define ESPI_EV_TNF BIT(8)
39 #define ESPI_EV_DON BIT(14)
40 #define ESPI_EV_TXE BIT(15)
41 #define ESPI_EV_RFCNT_SHIFT 24
42 #define ESPI_EV_RFCNT_MASK (0x3f << ESPI_EV_RFCNT_SHIFT)
44 #define ESPI_MODE_EN BIT(31) /* Enable interface */
45 #define ESPI_MODE_TXTHR(x) ((x) << 8) /* Tx FIFO threshold */
46 #define ESPI_MODE_RXTHR(x) ((x) << 0) /* Rx FIFO threshold */
48 #define ESPI_COM_CS(x) ((x) << 30)
49 #define ESPI_COM_TRANLEN(x) ((x) << 0)
51 #define ESPI_CSMODE_CI_INACTIVEHIGH BIT(31)
52 #define ESPI_CSMODE_CP_BEGIN_EDGCLK BIT(30)
53 #define ESPI_CSMODE_REV_MSB_FIRST BIT(29)
54 #define ESPI_CSMODE_DIV16 BIT(28)
55 #define ESPI_CSMODE_PM(x) ((x) << 24)
56 #define ESPI_CSMODE_POL_ASSERTED_LOW BIT(20)
57 #define ESPI_CSMODE_LEN(x) ((x) << 16)
58 #define ESPI_CSMODE_CSBEF(x) ((x) << 12)
59 #define ESPI_CSMODE_CSAFT(x) ((x) << 8)
60 #define ESPI_CSMODE_CSCG(x) ((x) << 3)
62 #define ESPI_CSMODE_INIT_VAL (ESPI_CSMODE_POL_ASSERTED_LOW | \
63 ESPI_CSMODE_CSBEF(0) | ESPI_CSMODE_CSAFT(0) | \
66 #define ESPI_MAX_DATA_TRANSFER_LEN 0xFFF0
68 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
69 unsigned int max_hz, unsigned int mode)
71 struct fsl_spi_slave *fsl;
73 unsigned long spibrg = 0;
74 unsigned long spi_freq = 0;
77 if (!spi_cs_is_valid(bus, cs))
80 fsl = spi_alloc_slave(struct fsl_spi_slave, bus, cs);
84 fsl->espi = (void *)(CONFIG_SYS_MPC85xx_ESPI_ADDR);
86 fsl->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN;
88 /* Set eSPI BRG clock source */
89 get_sys_info(&sysinfo);
90 spibrg = sysinfo.freq_systembus / 2;
92 if ((spibrg / max_hz) > 32) {
93 fsl->div16 = ESPI_CSMODE_DIV16;
94 pm = spibrg / (max_hz * 16 * 2);
97 debug("Requested speed is too low: %d Hz, %ld Hz "
98 "is used.\n", max_hz, spibrg / (32 * 16));
101 pm = spibrg / (max_hz * 2);
107 spi_freq = spibrg / ((pm + 1) * 2 * 16);
109 spi_freq = spibrg / ((pm + 1) * 2);
111 /* set tx_timeout to 10 times of one espi FIFO entry go out */
112 fsl->tx_timeout = DIV_ROUND_UP((US_PER_SECOND * ESPI_FIFO_WIDTH_BIT
118 void spi_free_slave(struct spi_slave *slave)
120 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
124 int spi_claim_bus(struct spi_slave *slave)
126 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
127 ccsr_espi_t *espi = fsl->espi;
128 unsigned char pm = fsl->pm;
129 unsigned int cs = slave->cs;
130 unsigned int mode = fsl->mode;
131 unsigned int div16 = fsl->div16;
134 debug("%s: bus:%i cs:%i\n", __func__, slave->bus, cs);
136 /* Enable eSPI interface */
137 out_be32(&espi->mode, ESPI_MODE_RXTHR(3)
138 | ESPI_MODE_TXTHR(4) | ESPI_MODE_EN);
140 out_be32(&espi->event, 0xffffffff); /* Clear all eSPI events */
141 out_be32(&espi->mask, 0x00000000); /* Mask all eSPI interrupts */
143 /* Init CS mode interface */
144 for (i = 0; i < ESPI_MAX_CS_NUM; i++)
145 out_be32(&espi->csmode[i], ESPI_CSMODE_INIT_VAL);
147 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs]) &
148 ~(ESPI_CSMODE_PM(0xF) | ESPI_CSMODE_DIV16
149 | ESPI_CSMODE_CI_INACTIVEHIGH | ESPI_CSMODE_CP_BEGIN_EDGCLK
150 | ESPI_CSMODE_REV_MSB_FIRST | ESPI_CSMODE_LEN(0xF)));
152 /* Set eSPI BRG clock source */
153 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
154 | ESPI_CSMODE_PM(pm) | div16);
158 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
159 | ESPI_CSMODE_CP_BEGIN_EDGCLK);
161 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
162 | ESPI_CSMODE_CI_INACTIVEHIGH);
164 /* Character bit order: msb first */
165 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
166 | ESPI_CSMODE_REV_MSB_FIRST);
168 /* Character length in bits, between 0x3~0xf, i.e. 4bits~16bits */
169 out_be32(&espi->csmode[cs], in_be32(&espi->csmode[cs])
170 | ESPI_CSMODE_LEN(7));
175 void spi_release_bus(struct spi_slave *slave)
180 static void fsl_espi_tx(struct fsl_spi_slave *fsl, const void *dout)
182 ccsr_espi_t *espi = fsl->espi;
183 unsigned int tmpdout, event;
187 tmpdout = *(u32 *)dout;
191 out_be32(&espi->tx, tmpdout);
192 out_be32(&espi->event, ESPI_EV_TNF);
193 debug("***spi_xfer:...%08x written\n", tmpdout);
195 tmp_tx_timeout = fsl->tx_timeout;
196 /* Wait for eSPI transmit to go out */
197 while (tmp_tx_timeout--) {
198 event = in_be32(&espi->event);
199 if (event & ESPI_EV_DON || event & ESPI_EV_TXE) {
200 out_be32(&espi->event, ESPI_EV_TXE);
206 if (tmp_tx_timeout < 0)
207 debug("***spi_xfer:...Tx timeout! event = %08x\n", event);
210 static int fsl_espi_rx(struct fsl_spi_slave *fsl, void *din, unsigned int bytes)
212 ccsr_espi_t *espi = fsl->espi;
213 unsigned int tmpdin, rx_times;
214 unsigned char *buf, *p_cursor;
219 rx_times = DIV_ROUND_UP(bytes, 4);
220 buf = (unsigned char *)malloc(4 * rx_times);
222 debug("SF: Failed to malloc memory.\n");
227 tmpdin = in_be32(&espi->rx);
228 debug("***spi_xfer:...%08x readed\n", tmpdin);
229 *(u32 *)p_cursor = tmpdin;
234 memcpy(din, buf, bytes);
237 out_be32(&espi->event, ESPI_EV_RNE);
242 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *data_out,
243 void *data_in, unsigned long flags)
245 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
246 ccsr_espi_t *espi = fsl->espi;
247 unsigned int event, rx_bytes;
248 const void *dout = NULL;
251 int num_blks, num_chunks, max_tran_len, tran_len;
253 unsigned char *buffer = NULL;
255 u8 *cmd_buf = fsl->cmd_buf;
256 size_t cmd_len = fsl->cmd_len;
257 size_t data_len = bitlen / 8;
258 size_t rx_offset = 0;
261 max_tran_len = fsl->max_transfer_length;
264 cmd_len = fsl->cmd_len = data_len;
265 memcpy(cmd_buf, data_out, cmd_len);
270 spi_cs_deactivate(slave);
273 buf_len = 2 * cmd_len + min(data_len, (size_t)max_tran_len);
274 len = cmd_len + data_len;
276 buffer = (unsigned char *)malloc(buf_len);
278 debug("SF: Failed to malloc memory.\n");
281 memcpy(buffer, cmd_buf, cmd_len);
283 memcpy(buffer + cmd_len, data_out, data_len);
285 case SPI_XFER_BEGIN | SPI_XFER_END:
287 buffer = (unsigned char *)malloc(len * 2);
289 debug("SF: Failed to malloc memory.\n");
292 memcpy(buffer, data_out, len);
298 debug("spi_xfer: data_out %08X(%p) data_in %08X(%p) len %u\n",
299 *(uint *)data_out, data_out, *(uint *)data_in, data_in, len);
301 num_chunks = DIV_ROUND_UP(data_len, max_tran_len);
302 while (num_chunks--) {
304 din = buffer + rx_offset;
306 tran_len = min(data_len, (size_t)max_tran_len);
307 num_blks = DIV_ROUND_UP(tran_len + cmd_len, 4);
308 num_bytes = (tran_len + cmd_len) % 4;
309 fsl->data_len = tran_len + cmd_len;
310 spi_cs_activate(slave);
312 /* Clear all eSPI events */
313 out_be32(&espi->event , 0xffffffff);
314 /* handle data in 32-bit chunks */
316 event = in_be32(&espi->event);
317 if (event & ESPI_EV_TNF) {
318 fsl_espi_tx(fsl, dout);
319 /* Set up the next iteration */
326 event = in_be32(&espi->event);
327 if (event & ESPI_EV_RNE) {
328 rf_cnt = ((event & ESPI_EV_RFCNT_MASK)
329 >> ESPI_EV_RFCNT_SHIFT);
332 else if (num_blks == 1 && rf_cnt == num_bytes)
333 rx_bytes = num_bytes;
336 if (fsl_espi_rx(fsl, din, rx_bytes)
340 din = (unsigned char *)din
346 memcpy(data_in, buffer + 2 * cmd_len, tran_len);
347 if (*buffer == 0x0b) {
349 data_len -= tran_len;
350 *(int *)buffer += tran_len;
353 spi_cs_deactivate(slave);
360 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
362 return bus == 0 && cs < ESPI_MAX_CS_NUM;
365 void spi_cs_activate(struct spi_slave *slave)
367 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
368 ccsr_espi_t *espi = fsl->espi;
369 unsigned int com = 0;
370 size_t data_len = fsl->data_len;
372 com &= ~(ESPI_COM_CS(0x3) | ESPI_COM_TRANLEN(0xFFFF));
373 com |= ESPI_COM_CS(slave->cs);
374 com |= ESPI_COM_TRANLEN(data_len - 1);
375 out_be32(&espi->com, com);
378 void spi_cs_deactivate(struct spi_slave *slave)
380 struct fsl_spi_slave *fsl = to_fsl_spi_slave(slave);
381 ccsr_espi_t *espi = fsl->espi;
383 /* clear the RXCNT and TXCNT */
384 out_be32(&espi->mode, in_be32(&espi->mode) & (~ESPI_MODE_EN));
385 out_be32(&espi->mode, in_be32(&espi->mode) | ESPI_MODE_EN);