xref: /openbmc/u-boot/drivers/spi/mpc8xx_spi.c (revision dd1033e4)
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 <dm.h>
21 #include <mpc8xx.h>
22 #include <spi.h>
23 
24 #include <asm/cpm_8xx.h>
25 #include <asm/io.h>
26 
27 #define CPM_SPI_BASE_RX	CPM_SPI_BASE
28 #define CPM_SPI_BASE_TX	(CPM_SPI_BASE + sizeof(cbd_t))
29 
30 #define MAX_BUFFER	0x104
31 
32 static int mpc8xx_spi_probe(struct udevice *dev)
33 {
34 	immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
35 	cpm8xx_t __iomem *cp = &immr->im_cpm;
36 	spi_t __iomem *spi = (spi_t __iomem *)&cp->cp_dparam[PROFF_SPI];
37 	cbd_t __iomem *tbdf, *rbdf;
38 
39 	/* Disable relocation */
40 	out_be16(&spi->spi_rpbase, 0);
41 
42 /* 1 */
43 	/* ------------------------------------------------
44 	 * Initialize Port B SPI pins -> page 34-8 MPC860UM
45 	 * (we are only in Master Mode !)
46 	 * ------------------------------------------------ */
47 
48 	/* --------------------------------------------
49 	 * GPIO or per. Function
50 	 * PBPAR[28] = 1 [0x00000008] -> PERI: (SPIMISO)
51 	 * PBPAR[29] = 1 [0x00000004] -> PERI: (SPIMOSI)
52 	 * PBPAR[30] = 1 [0x00000002] -> PERI: (SPICLK)
53 	 * PBPAR[31] = 0 [0x00000001] -> GPIO: (CS for PCUE/CCM-EEPROM)
54 	 * -------------------------------------------- */
55 	clrsetbits_be32(&cp->cp_pbpar, 0x00000001, 0x0000000E);	/* set  bits */
56 
57 	/* ----------------------------------------------
58 	 * In/Out or per. Function 0/1
59 	 * PBDIR[28] = 1 [0x00000008] -> PERI1: SPIMISO
60 	 * PBDIR[29] = 1 [0x00000004] -> PERI1: SPIMOSI
61 	 * PBDIR[30] = 1 [0x00000002] -> PERI1: SPICLK
62 	 * PBDIR[31] = 1 [0x00000001] -> GPIO OUT: CS for PCUE/CCM-EEPROM
63 	 * ---------------------------------------------- */
64 	setbits_be32(&cp->cp_pbdir, 0x0000000F);
65 
66 	/* ----------------------------------------------
67 	 * open drain or active output
68 	 * PBODR[28] = 1 [0x00000008] -> open drain: SPIMISO
69 	 * PBODR[29] = 0 [0x00000004] -> active output SPIMOSI
70 	 * PBODR[30] = 0 [0x00000002] -> active output: SPICLK
71 	 * PBODR[31] = 0 [0x00000001] -> active output GPIO OUT: CS for PCUE/CCM
72 	 * ---------------------------------------------- */
73 
74 	clrsetbits_be16(&cp->cp_pbodr, 0x00000007, 0x00000008);
75 
76 	/* Initialize the parameter ram.
77 	 * We need to make sure many things are initialized to zero
78 	 */
79 	out_be32(&spi->spi_rstate, 0);
80 	out_be32(&spi->spi_rdp, 0);
81 	out_be16(&spi->spi_rbptr, 0);
82 	out_be16(&spi->spi_rbc, 0);
83 	out_be32(&spi->spi_rxtmp, 0);
84 	out_be32(&spi->spi_tstate, 0);
85 	out_be32(&spi->spi_tdp, 0);
86 	out_be16(&spi->spi_tbptr, 0);
87 	out_be16(&spi->spi_tbc, 0);
88 	out_be32(&spi->spi_txtmp, 0);
89 
90 /* 3 */
91 	/* Set up the SPI parameters in the parameter ram */
92 	out_be16(&spi->spi_rbase, CPM_SPI_BASE_RX);
93 	out_be16(&spi->spi_tbase, CPM_SPI_BASE_TX);
94 
95 	/***********IMPORTANT******************/
96 
97 	/*
98 	 * Setting transmit and receive buffer descriptor pointers
99 	 * initially to rbase and tbase. Only the microcode patches
100 	 * documentation talks about initializing this pointer. This
101 	 * is missing from the sample I2C driver. If you dont
102 	 * initialize these pointers, the kernel hangs.
103 	 */
104 	out_be16(&spi->spi_rbptr, CPM_SPI_BASE_RX);
105 	out_be16(&spi->spi_tbptr, CPM_SPI_BASE_TX);
106 
107 /* 4 */
108 	/* Init SPI Tx + Rx Parameters */
109 	while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)
110 		;
111 
112 	out_be16(&cp->cp_cpcr, mk_cr_cmd(CPM_CR_CH_SPI, CPM_CR_INIT_TRX) |
113 			       CPM_CR_FLG);
114 	while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)
115 		;
116 
117 /* 5 */
118 	/* Set SDMA configuration register */
119 	out_be32(&immr->im_siu_conf.sc_sdcr, 0x0001);
120 
121 /* 6 */
122 	/* Set to big endian. */
123 	out_8(&spi->spi_tfcr, SMC_EB);
124 	out_8(&spi->spi_rfcr, SMC_EB);
125 
126 /* 7 */
127 	/* Set maximum receive size. */
128 	out_be16(&spi->spi_mrblr, MAX_BUFFER);
129 
130 /* 8 + 9 */
131 	/* tx and rx buffer descriptors */
132 	tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
133 	rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
134 
135 	clrbits_be16(&tbdf->cbd_sc, BD_SC_READY);
136 	clrbits_be16(&rbdf->cbd_sc, BD_SC_EMPTY);
137 
138 /* 10 + 11 */
139 	out_8(&cp->cp_spim, 0);			/* Mask  all SPI events */
140 	out_8(&cp->cp_spie, SPI_EMASK);		/* Clear all SPI events	*/
141 
142 	return 0;
143 }
144 
145 static int mpc8xx_spi_xfer(struct udevice *dev, unsigned int bitlen,
146 			    const void *dout, void *din, unsigned long flags)
147 {
148 	immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
149 	cpm8xx_t __iomem *cp = &immr->im_cpm;
150 	cbd_t __iomem *tbdf, *rbdf;
151 	int tm;
152 	size_t count = (bitlen + 7) / 8;
153 
154 	if (count > MAX_BUFFER)
155 		return -EINVAL;
156 
157 	tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
158 	rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
159 
160 	/* Set CS for device */
161 	clrbits_be32(&cp->cp_pbdat, 0x0001);
162 
163 	/* Setting tx bd status and data length */
164 	out_be32(&tbdf->cbd_bufaddr, (ulong)dout);
165 	out_be16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_LAST | BD_SC_WRAP);
166 	out_be16(&tbdf->cbd_datlen, count);
167 
168 	/* Setting rx bd status and data length */
169 	out_be32(&rbdf->cbd_bufaddr, (ulong)din);
170 	out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_WRAP);
171 	out_be16(&rbdf->cbd_datlen, 0);	 /* rx length has no significance */
172 
173 	clrsetbits_be16(&cp->cp_spmode, ~SPMODE_LOOP, SPMODE_REV | SPMODE_MSTR |
174 			SPMODE_EN | SPMODE_LEN(8) | SPMODE_PM(0x8));
175 	out_8(&cp->cp_spim, 0);		/* Mask  all SPI events */
176 	out_8(&cp->cp_spie, SPI_EMASK);	/* Clear all SPI events	*/
177 
178 	/* start spi transfer */
179 	setbits_8(&cp->cp_spcom, SPI_STR);		/* Start transmit */
180 
181 	/* --------------------------------
182 	 * Wait for SPI transmit to get out
183 	 * or time out (1 second = 1000 ms)
184 	 * -------------------------------- */
185 	for (tm = 0; tm < 1000; ++tm) {
186 		if (in_8(&cp->cp_spie) & SPI_TXB)	/* Tx Buffer Empty */
187 			break;
188 		if ((in_be16(&tbdf->cbd_sc) & BD_SC_READY) == 0)
189 			break;
190 		udelay(1000);
191 	}
192 	if (tm >= 1000)
193 		printf("*** spi_xfer: Time out while xferring to/from SPI!\n");
194 
195 	/* Clear CS for device */
196 	setbits_be32(&cp->cp_pbdat, 0x0001);
197 
198 	return count;
199 }
200 
201 static const struct dm_spi_ops mpc8xx_spi_ops = {
202 	.xfer		= mpc8xx_spi_xfer,
203 };
204 
205 static const struct udevice_id mpc8xx_spi_ids[] = {
206 	{ .compatible = "fsl,mpc8xx-spi" },
207 	{ }
208 };
209 
210 U_BOOT_DRIVER(mpc8xx_spi) = {
211 	.name	= "mpc8xx_spi",
212 	.id	= UCLASS_SPI,
213 	.of_match = mpc8xx_spi_ids,
214 	.ops	= &mpc8xx_spi_ops,
215 	.probe	= mpc8xx_spi_probe,
216 };
217