xref: /openbmc/u-boot/drivers/spi/mpc8xx_spi.c (revision 12308b12)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2001 Navin Boppuri / Prashant Patel
4  *	<nboppuri@trinetcommunication.com>,
5  *	<pmpatel@trinetcommunication.com>
6  * Copyright (c) 2001 Gerd Mennchen <Gerd.Mennchen@icn.siemens.de>
7  * Copyright (c) 2001 Wolfgang Denk, DENX Software Engineering, <wd@denx.de>.
8  */
9 
10 /*
11  * MPC8xx CPM SPI interface.
12  *
13  * Parts of this code are probably not portable and/or specific to
14  * the board which I used for the tests. Please send fixes/complaints
15  * to wd@denx.de
16  *
17  */
18 
19 #include <common.h>
20 #include <mpc8xx.h>
21 #include <asm/cpm_8xx.h>
22 #include <linux/ctype.h>
23 #include <malloc.h>
24 #include <post.h>
25 #include <serial.h>
26 
27 #define SPI_EEPROM_WREN		0x06
28 #define SPI_EEPROM_RDSR		0x05
29 #define SPI_EEPROM_READ		0x03
30 #define SPI_EEPROM_WRITE	0x02
31 
32 /* ---------------------------------------------------------------
33  * Offset for initial SPI buffers in DPRAM:
34  * We need a 520 byte scratch DPRAM area to use at an early stage.
35  * It is used between the two initialization calls (spi_init_f()
36  * and spi_init_r()).
37  * The value 0xb00 makes it far enough from the start of the data
38  * area (as well as from the stack pointer).
39  * --------------------------------------------------------------- */
40 #ifndef	CONFIG_SYS_SPI_INIT_OFFSET
41 #define	CONFIG_SYS_SPI_INIT_OFFSET	0xB00
42 #endif
43 
44 #define CPM_SPI_BASE_RX	CPM_SPI_BASE
45 #define CPM_SPI_BASE_TX	(CPM_SPI_BASE + sizeof(cbd_t))
46 
47 /* -------------------
48  * Function prototypes
49  * ------------------- */
50 ssize_t spi_xfer(size_t);
51 
52 /* -------------------
53  * Variables
54  * ------------------- */
55 
56 #define MAX_BUFFER	0x104
57 
58 /* ----------------------------------------------------------------------
59  * Initially we place the RX and TX buffers at a fixed location in DPRAM!
60  * ---------------------------------------------------------------------- */
61 static uchar *rxbuf =
62 	(uchar *)&((cpm8xx_t *)&((immap_t *)CONFIG_SYS_IMMR)->im_cpm)->cp_dpmem
63 			[CONFIG_SYS_SPI_INIT_OFFSET];
64 static uchar *txbuf =
65 	(uchar *)&((cpm8xx_t *)&((immap_t *)CONFIG_SYS_IMMR)->im_cpm)->cp_dpmem
66 			[CONFIG_SYS_SPI_INIT_OFFSET+MAX_BUFFER];
67 
68 /* **************************************************************************
69  *
70  *  Function:    spi_init_f
71  *
72  *  Description: Init SPI-Controller (ROM part)
73  *
74  *  return:      ---
75  *
76  * *********************************************************************** */
77 void spi_init_f(void)
78 {
79 	immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
80 	cpm8xx_t __iomem *cp = &immr->im_cpm;
81 	spi_t __iomem *spi = (spi_t __iomem *)&cp->cp_dparam[PROFF_SPI];
82 	cbd_t __iomem *tbdf, *rbdf;
83 
84 	/* Disable relocation */
85 	out_be16(&spi->spi_rpbase, 0);
86 
87 /* 1 */
88 	/* ------------------------------------------------
89 	 * Initialize Port B SPI pins -> page 34-8 MPC860UM
90 	 * (we are only in Master Mode !)
91 	 * ------------------------------------------------ */
92 
93 	/* --------------------------------------------
94 	 * GPIO or per. Function
95 	 * PBPAR[28] = 1 [0x00000008] -> PERI: (SPIMISO)
96 	 * PBPAR[29] = 1 [0x00000004] -> PERI: (SPIMOSI)
97 	 * PBPAR[30] = 1 [0x00000002] -> PERI: (SPICLK)
98 	 * PBPAR[31] = 0 [0x00000001] -> GPIO: (CS for PCUE/CCM-EEPROM)
99 	 * -------------------------------------------- */
100 	clrsetbits_be32(&cp->cp_pbpar, 0x00000001, 0x0000000E);	/* set  bits */
101 
102 	/* ----------------------------------------------
103 	 * In/Out or per. Function 0/1
104 	 * PBDIR[28] = 1 [0x00000008] -> PERI1: SPIMISO
105 	 * PBDIR[29] = 1 [0x00000004] -> PERI1: SPIMOSI
106 	 * PBDIR[30] = 1 [0x00000002] -> PERI1: SPICLK
107 	 * PBDIR[31] = 1 [0x00000001] -> GPIO OUT: CS for PCUE/CCM-EEPROM
108 	 * ---------------------------------------------- */
109 	setbits_be32(&cp->cp_pbdir, 0x0000000F);
110 
111 	/* ----------------------------------------------
112 	 * open drain or active output
113 	 * PBODR[28] = 1 [0x00000008] -> open drain: SPIMISO
114 	 * PBODR[29] = 0 [0x00000004] -> active output SPIMOSI
115 	 * PBODR[30] = 0 [0x00000002] -> active output: SPICLK
116 	 * PBODR[31] = 0 [0x00000001] -> active output GPIO OUT: CS for PCUE/CCM
117 	 * ---------------------------------------------- */
118 
119 	clrsetbits_be16(&cp->cp_pbodr, 0x00000007, 0x00000008);
120 
121 	/* Initialize the parameter ram.
122 	 * We need to make sure many things are initialized to zero
123 	 */
124 	out_be32(&spi->spi_rstate, 0);
125 	out_be32(&spi->spi_rdp, 0);
126 	out_be16(&spi->spi_rbptr, 0);
127 	out_be16(&spi->spi_rbc, 0);
128 	out_be32(&spi->spi_rxtmp, 0);
129 	out_be32(&spi->spi_tstate, 0);
130 	out_be32(&spi->spi_tdp, 0);
131 	out_be16(&spi->spi_tbptr, 0);
132 	out_be16(&spi->spi_tbc, 0);
133 	out_be32(&spi->spi_txtmp, 0);
134 
135 /* 3 */
136 	/* Set up the SPI parameters in the parameter ram */
137 	out_be16(&spi->spi_rbase, CPM_SPI_BASE_RX);
138 	out_be16(&spi->spi_tbase, CPM_SPI_BASE_TX);
139 
140 	/***********IMPORTANT******************/
141 
142 	/*
143 	 * Setting transmit and receive buffer descriptor pointers
144 	 * initially to rbase and tbase. Only the microcode patches
145 	 * documentation talks about initializing this pointer. This
146 	 * is missing from the sample I2C driver. If you dont
147 	 * initialize these pointers, the kernel hangs.
148 	 */
149 	out_be16(&spi->spi_rbptr, CPM_SPI_BASE_RX);
150 	out_be16(&spi->spi_tbptr, CPM_SPI_BASE_TX);
151 
152 /* 4 */
153 	/* Init SPI Tx + Rx Parameters */
154 	while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)
155 		;
156 
157 	out_be16(&cp->cp_cpcr, mk_cr_cmd(CPM_CR_CH_SPI, CPM_CR_INIT_TRX) |
158 			       CPM_CR_FLG);
159 	while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)
160 		;
161 
162 /* 5 */
163 	/* Set SDMA configuration register */
164 	out_be32(&immr->im_siu_conf.sc_sdcr, 0x0001);
165 
166 /* 6 */
167 	/* Set to big endian. */
168 	out_8(&spi->spi_tfcr, SMC_EB);
169 	out_8(&spi->spi_rfcr, SMC_EB);
170 
171 /* 7 */
172 	/* Set maximum receive size. */
173 	out_be16(&spi->spi_mrblr, MAX_BUFFER);
174 
175 /* 8 + 9 */
176 	/* tx and rx buffer descriptors */
177 	tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
178 	rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
179 
180 	clrbits_be16(&tbdf->cbd_sc, BD_SC_READY);
181 	clrbits_be16(&rbdf->cbd_sc, BD_SC_EMPTY);
182 
183 	/* Set the bd's rx and tx buffer address pointers */
184 	out_be32(&rbdf->cbd_bufaddr, (ulong)rxbuf);
185 	out_be32(&tbdf->cbd_bufaddr, (ulong)txbuf);
186 
187 /* 10 + 11 */
188 	out_8(&cp->cp_spim, 0);			/* Mask  all SPI events */
189 	out_8(&cp->cp_spie, SPI_EMASK);		/* Clear all SPI events	*/
190 
191 	return;
192 }
193 
194 /* **************************************************************************
195  *
196  *  Function:    spi_init_r
197  *
198  *  Description: Init SPI-Controller (RAM part) -
199  *		 The malloc engine is ready and we can move our buffers to
200  *		 normal RAM
201  *
202  *  return:      ---
203  *
204  * *********************************************************************** */
205 void spi_init_r(void)
206 {
207 	immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
208 	cpm8xx_t __iomem *cp = &immr->im_cpm;
209 	spi_t __iomem *spi = (spi_t __iomem *)&cp->cp_dparam[PROFF_SPI];
210 	cbd_t __iomem *tbdf, *rbdf;
211 
212 	/* Disable relocation */
213 	out_be16(&spi->spi_rpbase, 0);
214 
215 	/* tx and rx buffer descriptors */
216 	tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
217 	rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
218 
219 	/* Allocate memory for RX and TX buffers */
220 	rxbuf = (uchar *)malloc(MAX_BUFFER);
221 	txbuf = (uchar *)malloc(MAX_BUFFER);
222 
223 	out_be32(&rbdf->cbd_bufaddr, (ulong)rxbuf);
224 	out_be32(&tbdf->cbd_bufaddr, (ulong)txbuf);
225 
226 	return;
227 }
228 
229 /****************************************************************************
230  *  Function:    spi_write
231  **************************************************************************** */
232 ssize_t spi_write(uchar *addr, int alen, uchar *buffer, int len)
233 {
234 	int i;
235 
236 	memset(rxbuf, 0, MAX_BUFFER);
237 	memset(txbuf, 0, MAX_BUFFER);
238 	*txbuf = SPI_EEPROM_WREN;		/* write enable		*/
239 	spi_xfer(1);
240 	memcpy(txbuf, addr, alen);
241 	*txbuf = SPI_EEPROM_WRITE;		/* WRITE memory array	*/
242 	memcpy(alen + txbuf, buffer, len);
243 	spi_xfer(alen + len);
244 						/* ignore received data	*/
245 	for (i = 0; i < 1000; i++) {
246 		*txbuf = SPI_EEPROM_RDSR;	/* read status		*/
247 		txbuf[1] = 0;
248 		spi_xfer(2);
249 		if (!(rxbuf[1] & 1))
250 			break;
251 		udelay(1000);
252 	}
253 	if (i >= 1000)
254 		printf("*** spi_write: Time out while writing!\n");
255 
256 	return len;
257 }
258 
259 /****************************************************************************
260  *  Function:    spi_read
261  **************************************************************************** */
262 ssize_t spi_read(uchar *addr, int alen, uchar *buffer, int len)
263 {
264 	memset(rxbuf, 0, MAX_BUFFER);
265 	memset(txbuf, 0, MAX_BUFFER);
266 	memcpy(txbuf, addr, alen);
267 	*txbuf = SPI_EEPROM_READ;		/* READ memory array	*/
268 
269 	/*
270 	 * There is a bug in 860T (?) that cuts the last byte of input
271 	 * if we're reading into DPRAM. The solution we choose here is
272 	 * to always read len+1 bytes (we have one extra byte at the
273 	 * end of the buffer).
274 	 */
275 	spi_xfer(alen + len + 1);
276 	memcpy(buffer, alen + rxbuf, len);
277 
278 	return len;
279 }
280 
281 /****************************************************************************
282  *  Function:    spi_xfer
283  **************************************************************************** */
284 ssize_t spi_xfer(size_t count)
285 {
286 	immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
287 	cpm8xx_t __iomem *cp = &immr->im_cpm;
288 	spi_t __iomem *spi = (spi_t __iomem *)&cp->cp_dparam[PROFF_SPI];
289 	cbd_t __iomem *tbdf, *rbdf;
290 	int tm;
291 
292 	/* Disable relocation */
293 	out_be16(&spi->spi_rpbase, 0);
294 
295 	tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
296 	rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
297 
298 	/* Set CS for device */
299 	clrbits_be32(&cp->cp_pbdat, 0x0001);
300 
301 	/* Setting tx bd status and data length */
302 	out_be16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_LAST | BD_SC_WRAP);
303 	out_be16(&tbdf->cbd_datlen, count);
304 
305 	/* Setting rx bd status and data length */
306 	out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_WRAP);
307 	out_be16(&rbdf->cbd_datlen, 0);	 /* rx length has no significance */
308 
309 	clrsetbits_be16(&cp->cp_spmode, ~SPMODE_LOOP, SPMODE_REV | SPMODE_MSTR |
310 			SPMODE_EN | SPMODE_LEN(8) | SPMODE_PM(0x8));
311 	out_8(&cp->cp_spim, 0);		/* Mask  all SPI events */
312 	out_8(&cp->cp_spie, SPI_EMASK);	/* Clear all SPI events	*/
313 
314 	/* start spi transfer */
315 	setbits_8(&cp->cp_spcom, SPI_STR);		/* Start transmit */
316 
317 	/* --------------------------------
318 	 * Wait for SPI transmit to get out
319 	 * or time out (1 second = 1000 ms)
320 	 * -------------------------------- */
321 	for (tm = 0; tm < 1000; ++tm) {
322 		if (in_8(&cp->cp_spie) & SPI_TXB)	/* Tx Buffer Empty */
323 			break;
324 		if ((in_be16(&tbdf->cbd_sc) & BD_SC_READY) == 0)
325 			break;
326 		udelay(1000);
327 	}
328 	if (tm >= 1000)
329 		printf("*** spi_xfer: Time out while xferring to/from SPI!\n");
330 
331 	/* Clear CS for device */
332 	setbits_be32(&cp->cp_pbdat, 0x0001);
333 
334 	return count;
335 }
336