xref: /openbmc/u-boot/drivers/spi/kirkwood_spi.c (revision dd580801)
1 /*
2  * (C) Copyright 2009
3  * Marvell Semiconductor <www.marvell.com>
4  * Written-by: Prafulla Wadaskar <prafulla@marvell.com>
5  *
6  * Derived from drivers/spi/mpc8xxx_spi.c
7  *
8  * SPDX-License-Identifier:	GPL-2.0+
9  */
10 
11 #include <common.h>
12 #include <malloc.h>
13 #include <spi.h>
14 #include <asm/io.h>
15 #include <asm/arch/soc.h>
16 #ifdef CONFIG_KIRKWOOD
17 #include <asm/arch/mpp.h>
18 #endif
19 #include <asm/arch-mvebu/spi.h>
20 
21 static struct kwspi_registers *spireg =
22 	(struct kwspi_registers *)MVEBU_SPI_BASE;
23 
24 #ifdef CONFIG_KIRKWOOD
25 static u32 cs_spi_mpp_back[2];
26 #endif
27 
28 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
29 				unsigned int max_hz, unsigned int mode)
30 {
31 	struct spi_slave *slave;
32 	u32 data;
33 #ifdef CONFIG_KIRKWOOD
34 	static const u32 kwspi_mpp_config[2][2] = {
35 		{ MPP0_SPI_SCn, 0 }, /* if cs == 0 */
36 		{ MPP7_SPI_SCn, 0 } /* if cs != 0 */
37 	};
38 #endif
39 
40 	if (!spi_cs_is_valid(bus, cs))
41 		return NULL;
42 
43 	slave = spi_alloc_slave_base(bus, cs);
44 	if (!slave)
45 		return NULL;
46 
47 	writel(KWSPI_SMEMRDY, &spireg->ctrl);
48 
49 	/* calculate spi clock prescaller using max_hz */
50 	data = ((CONFIG_SYS_TCLK / 2) / max_hz) + 0x10;
51 	data = data < KWSPI_CLKPRESCL_MIN ? KWSPI_CLKPRESCL_MIN : data;
52 	data = data > KWSPI_CLKPRESCL_MASK ? KWSPI_CLKPRESCL_MASK : data;
53 
54 	/* program spi clock prescaller using max_hz */
55 	writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg);
56 	debug("data = 0x%08x\n", data);
57 
58 	writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause);
59 	writel(KWSPI_IRQMASK, &spireg->irq_mask);
60 
61 #ifdef CONFIG_KIRKWOOD
62 	/* program mpp registers to select  SPI_CSn */
63 	kirkwood_mpp_conf(kwspi_mpp_config[cs ? 1 : 0], cs_spi_mpp_back);
64 #endif
65 
66 	return slave;
67 }
68 
69 void spi_free_slave(struct spi_slave *slave)
70 {
71 #ifdef CONFIG_KIRKWOOD
72 	kirkwood_mpp_conf(cs_spi_mpp_back, NULL);
73 #endif
74 	free(slave);
75 }
76 
77 #if defined(CONFIG_SYS_KW_SPI_MPP)
78 u32 spi_mpp_backup[4];
79 #endif
80 
81 __attribute__((weak)) int board_spi_claim_bus(struct spi_slave *slave)
82 {
83 	return 0;
84 }
85 
86 int spi_claim_bus(struct spi_slave *slave)
87 {
88 #if defined(CONFIG_SYS_KW_SPI_MPP)
89 	u32 config;
90 	u32 spi_mpp_config[4];
91 
92 	config = CONFIG_SYS_KW_SPI_MPP;
93 
94 	if (config & MOSI_MPP6)
95 		spi_mpp_config[0] = MPP6_SPI_MOSI;
96 	else
97 		spi_mpp_config[0] = MPP1_SPI_MOSI;
98 
99 	if (config & SCK_MPP10)
100 		spi_mpp_config[1] = MPP10_SPI_SCK;
101 	else
102 		spi_mpp_config[1] = MPP2_SPI_SCK;
103 
104 	if (config & MISO_MPP11)
105 		spi_mpp_config[2] = MPP11_SPI_MISO;
106 	else
107 		spi_mpp_config[2] = MPP3_SPI_MISO;
108 
109 	spi_mpp_config[3] = 0;
110 	spi_mpp_backup[3] = 0;
111 
112 	/* set new spi mpp and save current mpp config */
113 	kirkwood_mpp_conf(spi_mpp_config, spi_mpp_backup);
114 #endif
115 
116 	return board_spi_claim_bus(slave);
117 }
118 
119 __attribute__((weak)) void board_spi_release_bus(struct spi_slave *slave)
120 {
121 }
122 
123 void spi_release_bus(struct spi_slave *slave)
124 {
125 #if defined(CONFIG_SYS_KW_SPI_MPP)
126 	kirkwood_mpp_conf(spi_mpp_backup, NULL);
127 #endif
128 
129 	board_spi_release_bus(slave);
130 }
131 
132 #ifndef CONFIG_SPI_CS_IS_VALID
133 /*
134  * you can define this function board specific
135  * define above CONFIG in board specific config file and
136  * provide the function in board specific src file
137  */
138 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
139 {
140 	return bus == 0 && (cs == 0 || cs == 1);
141 }
142 #endif
143 
144 void spi_init(void)
145 {
146 }
147 
148 void spi_cs_activate(struct spi_slave *slave)
149 {
150 	setbits_le32(&spireg->ctrl, KWSPI_CSN_ACT);
151 }
152 
153 void spi_cs_deactivate(struct spi_slave *slave)
154 {
155 	clrbits_le32(&spireg->ctrl, KWSPI_CSN_ACT);
156 }
157 
158 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
159 	     void *din, unsigned long flags)
160 {
161 	unsigned int tmpdout, tmpdin;
162 	int tm, isread = 0;
163 
164 	debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
165 	      slave->bus, slave->cs, dout, din, bitlen);
166 
167 	if (flags & SPI_XFER_BEGIN)
168 		spi_cs_activate(slave);
169 
170 	/*
171 	 * handle data in 8-bit chunks
172 	 * TBD: 2byte xfer mode to be enabled
173 	 */
174 	clrsetbits_le32(&spireg->cfg, KWSPI_XFERLEN_MASK, KWSPI_XFERLEN_1BYTE);
175 
176 	while (bitlen > 4) {
177 		debug("loopstart bitlen %d\n", bitlen);
178 		tmpdout = 0;
179 
180 		/* Shift data so it's msb-justified */
181 		if (dout)
182 			tmpdout = *(u32 *)dout & 0xff;
183 
184 		clrbits_le32(&spireg->irq_cause, KWSPI_SMEMRDIRQ);
185 		writel(tmpdout, &spireg->dout);	/* Write the data out */
186 		debug("*** spi_xfer: ... %08x written, bitlen %d\n",
187 		      tmpdout, bitlen);
188 
189 		/*
190 		 * Wait for SPI transmit to get out
191 		 * or time out (1 second = 1000 ms)
192 		 * The NE event must be read and cleared first
193 		 */
194 		for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
195 			if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
196 				isread = 1;
197 				tmpdin = readl(&spireg->din);
198 				debug("spi_xfer: din %p..%08x read\n",
199 				      din, tmpdin);
200 
201 				if (din) {
202 					*((u8 *)din) = (u8)tmpdin;
203 					din += 1;
204 				}
205 				if (dout)
206 					dout += 1;
207 				bitlen -= 8;
208 			}
209 			if (isread)
210 				break;
211 		}
212 		if (tm >= KWSPI_TIMEOUT)
213 			printf("*** spi_xfer: Time out during SPI transfer\n");
214 
215 		debug("loopend bitlen %d\n", bitlen);
216 	}
217 
218 	if (flags & SPI_XFER_END)
219 		spi_cs_deactivate(slave);
220 
221 	return 0;
222 }
223