xref: /openbmc/u-boot/drivers/spi/kirkwood_spi.c (revision d5c5132f)
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 = (struct kwspi_registers *)KW_SPI_BASE;
22 
23 #ifdef CONFIG_KIRKWOOD
24 static u32 cs_spi_mpp_back[2];
25 #endif
26 
27 struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
28 				unsigned int max_hz, unsigned int mode)
29 {
30 	struct spi_slave *slave;
31 	u32 data;
32 #ifdef CONFIG_KIRKWOOD
33 	static const u32 kwspi_mpp_config[2][2] = {
34 		{ MPP0_SPI_SCn, 0 }, /* if cs == 0 */
35 		{ MPP7_SPI_SCn, 0 } /* if cs != 0 */
36 	};
37 #endif
38 
39 	if (!spi_cs_is_valid(bus, cs))
40 		return NULL;
41 
42 	slave = spi_alloc_slave_base(bus, cs);
43 	if (!slave)
44 		return NULL;
45 
46 	writel(KWSPI_SMEMRDY, &spireg->ctrl);
47 
48 	/* calculate spi clock prescaller using max_hz */
49 	data = ((CONFIG_SYS_TCLK / 2) / max_hz) + 0x10;
50 	data = data < KWSPI_CLKPRESCL_MIN ? KWSPI_CLKPRESCL_MIN : data;
51 	data = data > KWSPI_CLKPRESCL_MASK ? KWSPI_CLKPRESCL_MASK : data;
52 
53 	/* program spi clock prescaller using max_hz */
54 	writel(KWSPI_ADRLEN_3BYTE | data, &spireg->cfg);
55 	debug("data = 0x%08x\n", data);
56 
57 	writel(KWSPI_SMEMRDIRQ, &spireg->irq_cause);
58 	writel(KWSPI_IRQMASK, &spireg->irq_mask);
59 
60 #ifdef CONFIG_KIRKWOOD
61 	/* program mpp registers to select  SPI_CSn */
62 	kirkwood_mpp_conf(kwspi_mpp_config[cs ? 1 : 0], cs_spi_mpp_back);
63 #endif
64 
65 	return slave;
66 }
67 
68 void spi_free_slave(struct spi_slave *slave)
69 {
70 #ifdef CONFIG_KIRKWOOD
71 	kirkwood_mpp_conf(cs_spi_mpp_back, NULL);
72 #endif
73 	free(slave);
74 }
75 
76 #if defined(CONFIG_SYS_KW_SPI_MPP)
77 u32 spi_mpp_backup[4];
78 #endif
79 
80 __attribute__((weak)) int board_spi_claim_bus(struct spi_slave *slave)
81 {
82 	return 0;
83 }
84 
85 int spi_claim_bus(struct spi_slave *slave)
86 {
87 #if defined(CONFIG_SYS_KW_SPI_MPP)
88 	u32 config;
89 	u32 spi_mpp_config[4];
90 
91 	config = CONFIG_SYS_KW_SPI_MPP;
92 
93 	if (config & MOSI_MPP6)
94 		spi_mpp_config[0] = MPP6_SPI_MOSI;
95 	else
96 		spi_mpp_config[0] = MPP1_SPI_MOSI;
97 
98 	if (config & SCK_MPP10)
99 		spi_mpp_config[1] = MPP10_SPI_SCK;
100 	else
101 		spi_mpp_config[1] = MPP2_SPI_SCK;
102 
103 	if (config & MISO_MPP11)
104 		spi_mpp_config[2] = MPP11_SPI_MISO;
105 	else
106 		spi_mpp_config[2] = MPP3_SPI_MISO;
107 
108 	spi_mpp_config[3] = 0;
109 	spi_mpp_backup[3] = 0;
110 
111 	/* set new spi mpp and save current mpp config */
112 	kirkwood_mpp_conf(spi_mpp_config, spi_mpp_backup);
113 #endif
114 
115 	return board_spi_claim_bus(slave);
116 }
117 
118 __attribute__((weak)) void board_spi_release_bus(struct spi_slave *slave)
119 {
120 }
121 
122 void spi_release_bus(struct spi_slave *slave)
123 {
124 #if defined(CONFIG_SYS_KW_SPI_MPP)
125 	kirkwood_mpp_conf(spi_mpp_backup, NULL);
126 #endif
127 
128 	board_spi_release_bus(slave);
129 }
130 
131 #ifndef CONFIG_SPI_CS_IS_VALID
132 /*
133  * you can define this function board specific
134  * define above CONFIG in board specific config file and
135  * provide the function in board specific src file
136  */
137 int spi_cs_is_valid(unsigned int bus, unsigned int cs)
138 {
139 	return bus == 0 && (cs == 0 || cs == 1);
140 }
141 #endif
142 
143 void spi_init(void)
144 {
145 }
146 
147 void spi_cs_activate(struct spi_slave *slave)
148 {
149 	setbits_le32(&spireg->ctrl, KWSPI_CSN_ACT);
150 }
151 
152 void spi_cs_deactivate(struct spi_slave *slave)
153 {
154 	clrbits_le32(&spireg->ctrl, KWSPI_CSN_ACT);
155 }
156 
157 int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
158 	     void *din, unsigned long flags)
159 {
160 	unsigned int tmpdout, tmpdin;
161 	int tm, isread = 0;
162 
163 	debug("spi_xfer: slave %u:%u dout %p din %p bitlen %u\n",
164 	      slave->bus, slave->cs, dout, din, bitlen);
165 
166 	if (flags & SPI_XFER_BEGIN)
167 		spi_cs_activate(slave);
168 
169 	/*
170 	 * handle data in 8-bit chunks
171 	 * TBD: 2byte xfer mode to be enabled
172 	 */
173 	clrsetbits_le32(&spireg->cfg, KWSPI_XFERLEN_MASK, KWSPI_XFERLEN_1BYTE);
174 
175 	while (bitlen > 4) {
176 		debug("loopstart bitlen %d\n", bitlen);
177 		tmpdout = 0;
178 
179 		/* Shift data so it's msb-justified */
180 		if (dout)
181 			tmpdout = *(u32 *)dout & 0xff;
182 
183 		clrbits_le32(&spireg->irq_cause, KWSPI_SMEMRDIRQ);
184 		writel(tmpdout, &spireg->dout);	/* Write the data out */
185 		debug("*** spi_xfer: ... %08x written, bitlen %d\n",
186 		      tmpdout, bitlen);
187 
188 		/*
189 		 * Wait for SPI transmit to get out
190 		 * or time out (1 second = 1000 ms)
191 		 * The NE event must be read and cleared first
192 		 */
193 		for (tm = 0, isread = 0; tm < KWSPI_TIMEOUT; ++tm) {
194 			if (readl(&spireg->irq_cause) & KWSPI_SMEMRDIRQ) {
195 				isread = 1;
196 				tmpdin = readl(&spireg->din);
197 				debug("spi_xfer: din %p..%08x read\n",
198 				      din, tmpdin);
199 
200 				if (din) {
201 					*((u8 *)din) = (u8)tmpdin;
202 					din += 1;
203 				}
204 				if (dout)
205 					dout += 1;
206 				bitlen -= 8;
207 			}
208 			if (isread)
209 				break;
210 		}
211 		if (tm >= KWSPI_TIMEOUT)
212 			printf("*** spi_xfer: Time out during SPI transfer\n");
213 
214 		debug("loopend bitlen %d\n", bitlen);
215 	}
216 
217 	if (flags & SPI_XFER_END)
218 		spi_cs_deactivate(slave);
219 
220 	return 0;
221 }
222