blob: d23dc81a211edc865b516f07a1e8e3a45f9e4993 [file] [log] [blame]
Simon Glass623b6382014-10-13 23:42:00 -06001/*
2 * Copyright (c) 2014 Google, Inc
3 *
4 * (C) Copyright 2002
5 * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
6 *
7 * Influenced by code from:
8 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
9 *
10 * SPDX-License-Identifier: GPL-2.0+
11 */
12
13#include <common.h>
14#include <dm.h>
15#include <errno.h>
16#include <fdtdec.h>
17#include <malloc.h>
18#include <spi.h>
19#include <asm/gpio.h>
20
21DECLARE_GLOBAL_DATA_PTR;
22
23struct soft_spi_platdata {
Simon Glass050fb902015-01-05 20:05:40 -070024 struct gpio_desc cs;
25 struct gpio_desc sclk;
26 struct gpio_desc mosi;
27 struct gpio_desc miso;
Simon Glass623b6382014-10-13 23:42:00 -060028 int spi_delay_us;
Peng Fan102412c2016-05-03 10:02:21 +080029 int flags;
Simon Glass623b6382014-10-13 23:42:00 -060030};
31
Peng Fan102412c2016-05-03 10:02:21 +080032#define SPI_MASTER_NO_RX BIT(0)
33#define SPI_MASTER_NO_TX BIT(1)
34
Simon Glass623b6382014-10-13 23:42:00 -060035struct soft_spi_priv {
36 unsigned int mode;
37};
38
39static int soft_spi_scl(struct udevice *dev, int bit)
40{
Peng Fanb6d54d52016-05-03 10:02:20 +080041 struct udevice *bus = dev_get_parent(dev);
42 struct soft_spi_platdata *plat = dev_get_platdata(bus);
Simon Glass623b6382014-10-13 23:42:00 -060043
Simon Glass050fb902015-01-05 20:05:40 -070044 dm_gpio_set_value(&plat->sclk, bit);
Simon Glass623b6382014-10-13 23:42:00 -060045
46 return 0;
47}
48
49static int soft_spi_sda(struct udevice *dev, int bit)
50{
Peng Fanb6d54d52016-05-03 10:02:20 +080051 struct udevice *bus = dev_get_parent(dev);
52 struct soft_spi_platdata *plat = dev_get_platdata(bus);
Simon Glass623b6382014-10-13 23:42:00 -060053
Simon Glass050fb902015-01-05 20:05:40 -070054 dm_gpio_set_value(&plat->mosi, bit);
Simon Glass623b6382014-10-13 23:42:00 -060055
56 return 0;
57}
58
59static int soft_spi_cs_activate(struct udevice *dev)
60{
Peng Fanb6d54d52016-05-03 10:02:20 +080061 struct udevice *bus = dev_get_parent(dev);
62 struct soft_spi_platdata *plat = dev_get_platdata(bus);
Simon Glass623b6382014-10-13 23:42:00 -060063
Simon Glass050fb902015-01-05 20:05:40 -070064 dm_gpio_set_value(&plat->cs, 0);
65 dm_gpio_set_value(&plat->sclk, 0);
66 dm_gpio_set_value(&plat->cs, 1);
Simon Glass623b6382014-10-13 23:42:00 -060067
68 return 0;
69}
70
71static int soft_spi_cs_deactivate(struct udevice *dev)
72{
Peng Fanb6d54d52016-05-03 10:02:20 +080073 struct udevice *bus = dev_get_parent(dev);
74 struct soft_spi_platdata *plat = dev_get_platdata(bus);
Simon Glass623b6382014-10-13 23:42:00 -060075
Simon Glass050fb902015-01-05 20:05:40 -070076 dm_gpio_set_value(&plat->cs, 0);
Simon Glass623b6382014-10-13 23:42:00 -060077
78 return 0;
79}
80
81static int soft_spi_claim_bus(struct udevice *dev)
82{
83 /*
84 * Make sure the SPI clock is in idle state as defined for
85 * this slave.
86 */
87 return soft_spi_scl(dev, 0);
88}
89
90static int soft_spi_release_bus(struct udevice *dev)
91{
92 /* Nothing to do */
93 return 0;
94}
95
96/*-----------------------------------------------------------------------
97 * SPI transfer
98 *
99 * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
100 * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
101 *
102 * The source of the outgoing bits is the "dout" parameter and the
103 * destination of the input bits is the "din" parameter. Note that "dout"
104 * and "din" can point to the same memory location, in which case the
105 * input data overwrites the output data (since both are buffered by
106 * temporary variables, this is OK).
107 */
108static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
109 const void *dout, void *din, unsigned long flags)
110{
Peng Fanb6d54d52016-05-03 10:02:20 +0800111 struct udevice *bus = dev_get_parent(dev);
112 struct soft_spi_priv *priv = dev_get_priv(bus);
113 struct soft_spi_platdata *plat = dev_get_platdata(bus);
Simon Glass623b6382014-10-13 23:42:00 -0600114 uchar tmpdin = 0;
115 uchar tmpdout = 0;
116 const u8 *txd = dout;
117 u8 *rxd = din;
Simon Glass623b6382014-10-13 23:42:00 -0600118 int cpha = priv->mode & SPI_CPHA;
119 unsigned int j;
120
121 debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n",
122 dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd,
123 bitlen);
124
125 if (flags & SPI_XFER_BEGIN)
126 soft_spi_cs_activate(dev);
127
128 for (j = 0; j < bitlen; j++) {
129 /*
130 * Check if it is time to work on a new byte.
131 */
132 if ((j % 8) == 0) {
133 if (txd)
134 tmpdout = *txd++;
135 else
136 tmpdout = 0;
137 if (j != 0) {
138 if (rxd)
139 *rxd++ = tmpdin;
140 }
141 tmpdin = 0;
142 }
143
144 if (!cpha)
Simon Glass050fb902015-01-05 20:05:40 -0700145 soft_spi_scl(dev, 0);
Peng Fan102412c2016-05-03 10:02:21 +0800146 if ((plat->flags & SPI_MASTER_NO_TX) == 0)
147 soft_spi_sda(dev, !!(tmpdout & 0x80));
Simon Glass623b6382014-10-13 23:42:00 -0600148 udelay(plat->spi_delay_us);
149 if (cpha)
Simon Glass050fb902015-01-05 20:05:40 -0700150 soft_spi_scl(dev, 0);
Simon Glass623b6382014-10-13 23:42:00 -0600151 else
Simon Glass050fb902015-01-05 20:05:40 -0700152 soft_spi_scl(dev, 1);
Simon Glass623b6382014-10-13 23:42:00 -0600153 tmpdin <<= 1;
Peng Fan102412c2016-05-03 10:02:21 +0800154 if ((plat->flags & SPI_MASTER_NO_RX) == 0)
155 tmpdin |= dm_gpio_get_value(&plat->miso);
Simon Glass623b6382014-10-13 23:42:00 -0600156 tmpdout <<= 1;
157 udelay(plat->spi_delay_us);
158 if (cpha)
Simon Glass050fb902015-01-05 20:05:40 -0700159 soft_spi_scl(dev, 1);
Simon Glass623b6382014-10-13 23:42:00 -0600160 }
161 /*
162 * If the number of bits isn't a multiple of 8, shift the last
163 * bits over to left-justify them. Then store the last byte
164 * read in.
165 */
166 if (rxd) {
167 if ((bitlen % 8) != 0)
168 tmpdin <<= 8 - (bitlen % 8);
169 *rxd++ = tmpdin;
170 }
171
172 if (flags & SPI_XFER_END)
173 soft_spi_cs_deactivate(dev);
174
175 return 0;
176}
177
178static int soft_spi_set_speed(struct udevice *dev, unsigned int speed)
179{
180 /* Accept any speed */
181 return 0;
182}
183
184static int soft_spi_set_mode(struct udevice *dev, unsigned int mode)
185{
186 struct soft_spi_priv *priv = dev_get_priv(dev);
187
188 priv->mode = mode;
189
190 return 0;
191}
192
Simon Glass623b6382014-10-13 23:42:00 -0600193static const struct dm_spi_ops soft_spi_ops = {
194 .claim_bus = soft_spi_claim_bus,
195 .release_bus = soft_spi_release_bus,
196 .xfer = soft_spi_xfer,
197 .set_speed = soft_spi_set_speed,
198 .set_mode = soft_spi_set_mode,
199};
200
201static int soft_spi_ofdata_to_platdata(struct udevice *dev)
202{
203 struct soft_spi_platdata *plat = dev->platdata;
204 const void *blob = gd->fdt_blob;
205 int node = dev->of_offset;
206
Simon Glass623b6382014-10-13 23:42:00 -0600207 plat->spi_delay_us = fdtdec_get_int(blob, node, "spi-delay-us", 0);
208
209 return 0;
210}
211
212static int soft_spi_probe(struct udevice *dev)
213{
Simon Glassbcbe3d12015-09-28 23:32:01 -0600214 struct spi_slave *slave = dev_get_parent_priv(dev);
Simon Glass623b6382014-10-13 23:42:00 -0600215 struct soft_spi_platdata *plat = dev->platdata;
Simon Glass050fb902015-01-05 20:05:40 -0700216 int cs_flags, clk_flags;
Peng Fan102412c2016-05-03 10:02:21 +0800217 int ret;
Simon Glass623b6382014-10-13 23:42:00 -0600218
Simon Glass050fb902015-01-05 20:05:40 -0700219 cs_flags = (slave->mode & SPI_CS_HIGH) ? 0 : GPIOD_ACTIVE_LOW;
220 clk_flags = (slave->mode & SPI_CPOL) ? GPIOD_ACTIVE_LOW : 0;
Peng Fan102412c2016-05-03 10:02:21 +0800221
222 if (gpio_request_by_name(dev, "cs-gpios", 0, &plat->cs,
Simon Glass050fb902015-01-05 20:05:40 -0700223 GPIOD_IS_OUT | cs_flags) ||
Peng Fan102412c2016-05-03 10:02:21 +0800224 gpio_request_by_name(dev, "gpio-sck", 0, &plat->sclk,
225 GPIOD_IS_OUT | clk_flags))
226 return -EINVAL;
227
228 ret = gpio_request_by_name(dev, "gpio-mosi", 0, &plat->mosi,
229 GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
230 if (ret)
231 plat->flags |= SPI_MASTER_NO_TX;
232
233 ret = gpio_request_by_name(dev, "gpio-miso", 0, &plat->miso,
234 GPIOD_IS_IN);
235 if (ret)
236 plat->flags |= SPI_MASTER_NO_RX;
237
238 if ((plat->flags & (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX)) ==
239 (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX))
Simon Glass050fb902015-01-05 20:05:40 -0700240 return -EINVAL;
Simon Glass623b6382014-10-13 23:42:00 -0600241
242 return 0;
243}
244
245static const struct udevice_id soft_spi_ids[] = {
Peng Fan102412c2016-05-03 10:02:21 +0800246 { .compatible = "spi-gpio" },
Simon Glass623b6382014-10-13 23:42:00 -0600247 { }
248};
249
250U_BOOT_DRIVER(soft_spi) = {
251 .name = "soft_spi",
252 .id = UCLASS_SPI,
253 .of_match = soft_spi_ids,
254 .ops = &soft_spi_ops,
255 .ofdata_to_platdata = soft_spi_ofdata_to_platdata,
256 .platdata_auto_alloc_size = sizeof(struct soft_spi_platdata),
257 .priv_auto_alloc_size = sizeof(struct soft_spi_priv),
Simon Glass623b6382014-10-13 23:42:00 -0600258 .probe = soft_spi_probe,
Simon Glass623b6382014-10-13 23:42:00 -0600259};