xref: /openbmc/u-boot/drivers/spi/mpc8xx_spi.c (revision cf0bcd7d)
1 /*
2  * Copyright (c) 2001 Navin Boppuri / Prashant Patel
3  *	<nboppuri@trinetcommunication.com>,
4  *	<pmpatel@trinetcommunication.com>
5  * Copyright (c) 2001 Gerd Mennchen <Gerd.Mennchen@icn.siemens.de>
6  * Copyright (c) 2001 Wolfgang Denk, DENX Software Engineering, <wd@denx.de>.
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 /*
12  * MPC8xx CPM SPI interface.
13  *
14  * Parts of this code are probably not portable and/or specific to
15  * the board which I used for the tests. Please send fixes/complaints
16  * to wd@denx.de
17  *
18  */
19 
20 #include <common.h>
21 #include <mpc8xx.h>
22 #include <asm/cpm_8xx.h>
23 #include <linux/ctype.h>
24 #include <malloc.h>
25 #include <post.h>
26 #include <serial.h>
27 
28 #define SPI_EEPROM_WREN		0x06
29 #define SPI_EEPROM_RDSR		0x05
30 #define SPI_EEPROM_READ		0x03
31 #define SPI_EEPROM_WRITE	0x02
32 
33 /* ---------------------------------------------------------------
34  * Offset for initial SPI buffers in DPRAM:
35  * We need a 520 byte scratch DPRAM area to use at an early stage.
36  * It is used between the two initialization calls (spi_init_f()
37  * and spi_init_r()).
38  * The value 0xb00 makes it far enough from the start of the data
39  * area (as well as from the stack pointer).
40  * --------------------------------------------------------------- */
41 #ifndef	CONFIG_SYS_SPI_INIT_OFFSET
42 #define	CONFIG_SYS_SPI_INIT_OFFSET	0xB00
43 #endif
44 
45 #define CPM_SPI_BASE_RX	CPM_SPI_BASE
46 #define CPM_SPI_BASE_TX	(CPM_SPI_BASE + sizeof(cbd_t))
47 
48 /* -------------------
49  * Function prototypes
50  * ------------------- */
51 ssize_t spi_xfer(size_t);
52 
53 /* -------------------
54  * Variables
55  * ------------------- */
56 
57 #define MAX_BUFFER	0x104
58 
59 /* ----------------------------------------------------------------------
60  * Initially we place the RX and TX buffers at a fixed location in DPRAM!
61  * ---------------------------------------------------------------------- */
62 static uchar *rxbuf =
63 	(uchar *)&((cpm8xx_t *)&((immap_t *)CONFIG_SYS_IMMR)->im_cpm)->cp_dpmem
64 			[CONFIG_SYS_SPI_INIT_OFFSET];
65 static uchar *txbuf =
66 	(uchar *)&((cpm8xx_t *)&((immap_t *)CONFIG_SYS_IMMR)->im_cpm)->cp_dpmem
67 			[CONFIG_SYS_SPI_INIT_OFFSET+MAX_BUFFER];
68 
69 /* **************************************************************************
70  *
71  *  Function:    spi_init_f
72  *
73  *  Description: Init SPI-Controller (ROM part)
74  *
75  *  return:      ---
76  *
77  * *********************************************************************** */
78 void spi_init_f(void)
79 {
80 	immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
81 	cpm8xx_t __iomem *cp = &immr->im_cpm;
82 	spi_t __iomem *spi = (spi_t __iomem *)&cp->cp_dparam[PROFF_SPI];
83 	cbd_t __iomem *tbdf, *rbdf;
84 
85 	/* Disable relocation */
86 	out_be16(&spi->spi_rpbase, 0);
87 
88 /* 1 */
89 	/* ------------------------------------------------
90 	 * Initialize Port B SPI pins -> page 34-8 MPC860UM
91 	 * (we are only in Master Mode !)
92 	 * ------------------------------------------------ */
93 
94 	/* --------------------------------------------
95 	 * GPIO or per. Function
96 	 * PBPAR[28] = 1 [0x00000008] -> PERI: (SPIMISO)
97 	 * PBPAR[29] = 1 [0x00000004] -> PERI: (SPIMOSI)
98 	 * PBPAR[30] = 1 [0x00000002] -> PERI: (SPICLK)
99 	 * PBPAR[31] = 0 [0x00000001] -> GPIO: (CS for PCUE/CCM-EEPROM)
100 	 * -------------------------------------------- */
101 	clrsetbits_be32(&cp->cp_pbpar, 0x00000001, 0x0000000E);	/* set  bits */
102 
103 	/* ----------------------------------------------
104 	 * In/Out or per. Function 0/1
105 	 * PBDIR[28] = 1 [0x00000008] -> PERI1: SPIMISO
106 	 * PBDIR[29] = 1 [0x00000004] -> PERI1: SPIMOSI
107 	 * PBDIR[30] = 1 [0x00000002] -> PERI1: SPICLK
108 	 * PBDIR[31] = 1 [0x00000001] -> GPIO OUT: CS for PCUE/CCM-EEPROM
109 	 * ---------------------------------------------- */
110 	setbits_be32(&cp->cp_pbdir, 0x0000000F);
111 
112 	/* ----------------------------------------------
113 	 * open drain or active output
114 	 * PBODR[28] = 1 [0x00000008] -> open drain: SPIMISO
115 	 * PBODR[29] = 0 [0x00000004] -> active output SPIMOSI
116 	 * PBODR[30] = 0 [0x00000002] -> active output: SPICLK
117 	 * PBODR[31] = 0 [0x00000001] -> active output GPIO OUT: CS for PCUE/CCM
118 	 * ---------------------------------------------- */
119 
120 	clrsetbits_be16(&cp->cp_pbodr, 0x00000007, 0x00000008);
121 
122 	/* Initialize the parameter ram.
123 	 * We need to make sure many things are initialized to zero
124 	 */
125 	out_be32(&spi->spi_rstate, 0);
126 	out_be32(&spi->spi_rdp, 0);
127 	out_be16(&spi->spi_rbptr, 0);
128 	out_be16(&spi->spi_rbc, 0);
129 	out_be32(&spi->spi_rxtmp, 0);
130 	out_be32(&spi->spi_tstate, 0);
131 	out_be32(&spi->spi_tdp, 0);
132 	out_be16(&spi->spi_tbptr, 0);
133 	out_be16(&spi->spi_tbc, 0);
134 	out_be32(&spi->spi_txtmp, 0);
135 
136 /* 3 */
137 	/* Set up the SPI parameters in the parameter ram */
138 	out_be16(&spi->spi_rbase, CPM_SPI_BASE_RX);
139 	out_be16(&spi->spi_tbase, CPM_SPI_BASE_TX);
140 
141 	/***********IMPORTANT******************/
142 
143 	/*
144 	 * Setting transmit and receive buffer descriptor pointers
145 	 * initially to rbase and tbase. Only the microcode patches
146 	 * documentation talks about initializing this pointer. This
147 	 * is missing from the sample I2C driver. If you dont
148 	 * initialize these pointers, the kernel hangs.
149 	 */
150 	out_be16(&spi->spi_rbptr, CPM_SPI_BASE_RX);
151 	out_be16(&spi->spi_tbptr, CPM_SPI_BASE_TX);
152 
153 /* 4 */
154 	/* Init SPI Tx + Rx Parameters */
155 	while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)
156 		;
157 
158 	out_be16(&cp->cp_cpcr, mk_cr_cmd(CPM_CR_CH_SPI, CPM_CR_INIT_TRX) |
159 			       CPM_CR_FLG);
160 	while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)
161 		;
162 
163 /* 5 */
164 	/* Set SDMA configuration register */
165 	out_be32(&immr->im_siu_conf.sc_sdcr, 0x0001);
166 
167 /* 6 */
168 	/* Set to big endian. */
169 	out_8(&spi->spi_tfcr, SMC_EB);
170 	out_8(&spi->spi_rfcr, SMC_EB);
171 
172 /* 7 */
173 	/* Set maximum receive size. */
174 	out_be16(&spi->spi_mrblr, MAX_BUFFER);
175 
176 /* 8 + 9 */
177 	/* tx and rx buffer descriptors */
178 	tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
179 	rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
180 
181 	clrbits_be16(&tbdf->cbd_sc, BD_SC_READY);
182 	clrbits_be16(&rbdf->cbd_sc, BD_SC_EMPTY);
183 
184 	/* Set the bd's rx and tx buffer address pointers */
185 	out_be32(&rbdf->cbd_bufaddr, (ulong)rxbuf);
186 	out_be32(&tbdf->cbd_bufaddr, (ulong)txbuf);
187 
188 /* 10 + 11 */
189 	out_8(&cp->cp_spim, 0);			/* Mask  all SPI events */
190 	out_8(&cp->cp_spie, SPI_EMASK);		/* Clear all SPI events	*/
191 
192 	return;
193 }
194 
195 /* **************************************************************************
196  *
197  *  Function:    spi_init_r
198  *
199  *  Description: Init SPI-Controller (RAM part) -
200  *		 The malloc engine is ready and we can move our buffers to
201  *		 normal RAM
202  *
203  *  return:      ---
204  *
205  * *********************************************************************** */
206 void spi_init_r(void)
207 {
208 	immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
209 	cpm8xx_t __iomem *cp = &immr->im_cpm;
210 	spi_t __iomem *spi = (spi_t __iomem *)&cp->cp_dparam[PROFF_SPI];
211 	cbd_t __iomem *tbdf, *rbdf;
212 
213 	/* Disable relocation */
214 	out_be16(&spi->spi_rpbase, 0);
215 
216 	/* tx and rx buffer descriptors */
217 	tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
218 	rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
219 
220 	/* Allocate memory for RX and TX buffers */
221 	rxbuf = (uchar *)malloc(MAX_BUFFER);
222 	txbuf = (uchar *)malloc(MAX_BUFFER);
223 
224 	out_be32(&rbdf->cbd_bufaddr, (ulong)rxbuf);
225 	out_be32(&tbdf->cbd_bufaddr, (ulong)txbuf);
226 
227 	return;
228 }
229 
230 /****************************************************************************
231  *  Function:    spi_write
232  **************************************************************************** */
233 ssize_t spi_write(uchar *addr, int alen, uchar *buffer, int len)
234 {
235 	int i;
236 
237 	memset(rxbuf, 0, MAX_BUFFER);
238 	memset(txbuf, 0, MAX_BUFFER);
239 	*txbuf = SPI_EEPROM_WREN;		/* write enable		*/
240 	spi_xfer(1);
241 	memcpy(txbuf, addr, alen);
242 	*txbuf = SPI_EEPROM_WRITE;		/* WRITE memory array	*/
243 	memcpy(alen + txbuf, buffer, len);
244 	spi_xfer(alen + len);
245 						/* ignore received data	*/
246 	for (i = 0; i < 1000; i++) {
247 		*txbuf = SPI_EEPROM_RDSR;	/* read status		*/
248 		txbuf[1] = 0;
249 		spi_xfer(2);
250 		if (!(rxbuf[1] & 1))
251 			break;
252 		udelay(1000);
253 	}
254 	if (i >= 1000)
255 		printf("*** spi_write: Time out while writing!\n");
256 
257 	return len;
258 }
259 
260 /****************************************************************************
261  *  Function:    spi_read
262  **************************************************************************** */
263 ssize_t spi_read(uchar *addr, int alen, uchar *buffer, int len)
264 {
265 	memset(rxbuf, 0, MAX_BUFFER);
266 	memset(txbuf, 0, MAX_BUFFER);
267 	memcpy(txbuf, addr, alen);
268 	*txbuf = SPI_EEPROM_READ;		/* READ memory array	*/
269 
270 	/*
271 	 * There is a bug in 860T (?) that cuts the last byte of input
272 	 * if we're reading into DPRAM. The solution we choose here is
273 	 * to always read len+1 bytes (we have one extra byte at the
274 	 * end of the buffer).
275 	 */
276 	spi_xfer(alen + len + 1);
277 	memcpy(buffer, alen + rxbuf, len);
278 
279 	return len;
280 }
281 
282 /****************************************************************************
283  *  Function:    spi_xfer
284  **************************************************************************** */
285 ssize_t spi_xfer(size_t count)
286 {
287 	immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
288 	cpm8xx_t __iomem *cp = &immr->im_cpm;
289 	spi_t __iomem *spi = (spi_t __iomem *)&cp->cp_dparam[PROFF_SPI];
290 	cbd_t __iomem *tbdf, *rbdf;
291 	int tm;
292 
293 	/* Disable relocation */
294 	out_be16(&spi->spi_rpbase, 0);
295 
296 	tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
297 	rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
298 
299 	/* Set CS for device */
300 	clrbits_be32(&cp->cp_pbdat, 0x0001);
301 
302 	/* Setting tx bd status and data length */
303 	out_be16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_LAST | BD_SC_WRAP);
304 	out_be16(&tbdf->cbd_datlen, count);
305 
306 	/* Setting rx bd status and data length */
307 	out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_WRAP);
308 	out_be16(&rbdf->cbd_datlen, 0);	 /* rx length has no significance */
309 
310 	clrsetbits_be16(&cp->cp_spmode, ~SPMODE_LOOP, SPMODE_REV | SPMODE_MSTR |
311 			SPMODE_EN | SPMODE_LEN(8) | SPMODE_PM(0x8));
312 	out_8(&cp->cp_spim, 0);		/* Mask  all SPI events */
313 	out_8(&cp->cp_spie, SPI_EMASK);	/* Clear all SPI events	*/
314 
315 	/* start spi transfer */
316 	setbits_8(&cp->cp_spcom, SPI_STR);		/* Start transmit */
317 
318 	/* --------------------------------
319 	 * Wait for SPI transmit to get out
320 	 * or time out (1 second = 1000 ms)
321 	 * -------------------------------- */
322 	for (tm = 0; tm < 1000; ++tm) {
323 		if (in_8(&cp->cp_spie) & SPI_TXB)	/* Tx Buffer Empty */
324 			break;
325 		if ((in_be16(&tbdf->cbd_sc) & BD_SC_READY) == 0)
326 			break;
327 		udelay(1000);
328 	}
329 	if (tm >= 1000)
330 		printf("*** spi_xfer: Time out while xferring to/from SPI!\n");
331 
332 	/* Clear CS for device */
333 	setbits_be32(&cp->cp_pbdat, 0x0001);
334 
335 	return count;
336 }
337