1*83d290c5STom Rini // SPDX-License-Identifier: GPL-2.0+
2623b6386SSimon Glass /*
3623b6386SSimon Glass * Copyright (c) 2014 Google, Inc
4623b6386SSimon Glass *
5623b6386SSimon Glass * (C) Copyright 2002
6623b6386SSimon Glass * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
7623b6386SSimon Glass *
8623b6386SSimon Glass * Influenced by code from:
9623b6386SSimon Glass * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
10623b6386SSimon Glass */
11623b6386SSimon Glass
12623b6386SSimon Glass #include <common.h>
13623b6386SSimon Glass #include <dm.h>
14623b6386SSimon Glass #include <errno.h>
15623b6386SSimon Glass #include <fdtdec.h>
16623b6386SSimon Glass #include <malloc.h>
17623b6386SSimon Glass #include <spi.h>
18623b6386SSimon Glass #include <asm/gpio.h>
19623b6386SSimon Glass
20623b6386SSimon Glass DECLARE_GLOBAL_DATA_PTR;
21623b6386SSimon Glass
22623b6386SSimon Glass struct soft_spi_platdata {
23050fb909SSimon Glass struct gpio_desc cs;
24050fb909SSimon Glass struct gpio_desc sclk;
25050fb909SSimon Glass struct gpio_desc mosi;
26050fb909SSimon Glass struct gpio_desc miso;
27623b6386SSimon Glass int spi_delay_us;
28102412c4SPeng Fan int flags;
29623b6386SSimon Glass };
30623b6386SSimon Glass
31102412c4SPeng Fan #define SPI_MASTER_NO_RX BIT(0)
32102412c4SPeng Fan #define SPI_MASTER_NO_TX BIT(1)
33102412c4SPeng Fan
34623b6386SSimon Glass struct soft_spi_priv {
35623b6386SSimon Glass unsigned int mode;
36623b6386SSimon Glass };
37623b6386SSimon Glass
soft_spi_scl(struct udevice * dev,int bit)38623b6386SSimon Glass static int soft_spi_scl(struct udevice *dev, int bit)
39623b6386SSimon Glass {
40b6d54d52SPeng Fan struct udevice *bus = dev_get_parent(dev);
41b6d54d52SPeng Fan struct soft_spi_platdata *plat = dev_get_platdata(bus);
42623b6386SSimon Glass
43050fb909SSimon Glass dm_gpio_set_value(&plat->sclk, bit);
44623b6386SSimon Glass
45623b6386SSimon Glass return 0;
46623b6386SSimon Glass }
47623b6386SSimon Glass
soft_spi_sda(struct udevice * dev,int bit)48623b6386SSimon Glass static int soft_spi_sda(struct udevice *dev, int bit)
49623b6386SSimon Glass {
50b6d54d52SPeng Fan struct udevice *bus = dev_get_parent(dev);
51b6d54d52SPeng Fan struct soft_spi_platdata *plat = dev_get_platdata(bus);
52623b6386SSimon Glass
53050fb909SSimon Glass dm_gpio_set_value(&plat->mosi, bit);
54623b6386SSimon Glass
55623b6386SSimon Glass return 0;
56623b6386SSimon Glass }
57623b6386SSimon Glass
soft_spi_cs_activate(struct udevice * dev)58623b6386SSimon Glass static int soft_spi_cs_activate(struct udevice *dev)
59623b6386SSimon Glass {
60b6d54d52SPeng Fan struct udevice *bus = dev_get_parent(dev);
61b6d54d52SPeng Fan struct soft_spi_platdata *plat = dev_get_platdata(bus);
62623b6386SSimon Glass
63050fb909SSimon Glass dm_gpio_set_value(&plat->cs, 0);
64050fb909SSimon Glass dm_gpio_set_value(&plat->sclk, 0);
65050fb909SSimon Glass dm_gpio_set_value(&plat->cs, 1);
66623b6386SSimon Glass
67623b6386SSimon Glass return 0;
68623b6386SSimon Glass }
69623b6386SSimon Glass
soft_spi_cs_deactivate(struct udevice * dev)70623b6386SSimon Glass static int soft_spi_cs_deactivate(struct udevice *dev)
71623b6386SSimon Glass {
72b6d54d52SPeng Fan struct udevice *bus = dev_get_parent(dev);
73b6d54d52SPeng Fan struct soft_spi_platdata *plat = dev_get_platdata(bus);
74623b6386SSimon Glass
75050fb909SSimon Glass dm_gpio_set_value(&plat->cs, 0);
76623b6386SSimon Glass
77623b6386SSimon Glass return 0;
78623b6386SSimon Glass }
79623b6386SSimon Glass
soft_spi_claim_bus(struct udevice * dev)80623b6386SSimon Glass static int soft_spi_claim_bus(struct udevice *dev)
81623b6386SSimon Glass {
82623b6386SSimon Glass /*
83623b6386SSimon Glass * Make sure the SPI clock is in idle state as defined for
84623b6386SSimon Glass * this slave.
85623b6386SSimon Glass */
86623b6386SSimon Glass return soft_spi_scl(dev, 0);
87623b6386SSimon Glass }
88623b6386SSimon Glass
soft_spi_release_bus(struct udevice * dev)89623b6386SSimon Glass static int soft_spi_release_bus(struct udevice *dev)
90623b6386SSimon Glass {
91623b6386SSimon Glass /* Nothing to do */
92623b6386SSimon Glass return 0;
93623b6386SSimon Glass }
94623b6386SSimon Glass
95623b6386SSimon Glass /*-----------------------------------------------------------------------
96623b6386SSimon Glass * SPI transfer
97623b6386SSimon Glass *
98623b6386SSimon Glass * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
99623b6386SSimon Glass * "bitlen" bits in the SPI MISO port. That's just the way SPI works.
100623b6386SSimon Glass *
101623b6386SSimon Glass * The source of the outgoing bits is the "dout" parameter and the
102623b6386SSimon Glass * destination of the input bits is the "din" parameter. Note that "dout"
103623b6386SSimon Glass * and "din" can point to the same memory location, in which case the
104623b6386SSimon Glass * input data overwrites the output data (since both are buffered by
105623b6386SSimon Glass * temporary variables, this is OK).
106623b6386SSimon Glass */
soft_spi_xfer(struct udevice * dev,unsigned int bitlen,const void * dout,void * din,unsigned long flags)107623b6386SSimon Glass static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
108623b6386SSimon Glass const void *dout, void *din, unsigned long flags)
109623b6386SSimon Glass {
110b6d54d52SPeng Fan struct udevice *bus = dev_get_parent(dev);
111b6d54d52SPeng Fan struct soft_spi_priv *priv = dev_get_priv(bus);
112b6d54d52SPeng Fan struct soft_spi_platdata *plat = dev_get_platdata(bus);
113623b6386SSimon Glass uchar tmpdin = 0;
114623b6386SSimon Glass uchar tmpdout = 0;
115623b6386SSimon Glass const u8 *txd = dout;
116623b6386SSimon Glass u8 *rxd = din;
117623b6386SSimon Glass int cpha = priv->mode & SPI_CPHA;
118623b6386SSimon Glass unsigned int j;
119623b6386SSimon Glass
120623b6386SSimon Glass debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n",
121623b6386SSimon Glass dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd,
122623b6386SSimon Glass bitlen);
123623b6386SSimon Glass
124623b6386SSimon Glass if (flags & SPI_XFER_BEGIN)
125623b6386SSimon Glass soft_spi_cs_activate(dev);
126623b6386SSimon Glass
127623b6386SSimon Glass for (j = 0; j < bitlen; j++) {
128623b6386SSimon Glass /*
129623b6386SSimon Glass * Check if it is time to work on a new byte.
130623b6386SSimon Glass */
131623b6386SSimon Glass if ((j % 8) == 0) {
132623b6386SSimon Glass if (txd)
133623b6386SSimon Glass tmpdout = *txd++;
134623b6386SSimon Glass else
135623b6386SSimon Glass tmpdout = 0;
136623b6386SSimon Glass if (j != 0) {
137623b6386SSimon Glass if (rxd)
138623b6386SSimon Glass *rxd++ = tmpdin;
139623b6386SSimon Glass }
140623b6386SSimon Glass tmpdin = 0;
141623b6386SSimon Glass }
142623b6386SSimon Glass
143623b6386SSimon Glass if (!cpha)
144050fb909SSimon Glass soft_spi_scl(dev, 0);
145102412c4SPeng Fan if ((plat->flags & SPI_MASTER_NO_TX) == 0)
146b6d54d52SPeng Fan soft_spi_sda(dev, !!(tmpdout & 0x80));
147623b6386SSimon Glass udelay(plat->spi_delay_us);
148623b6386SSimon Glass if (cpha)
149050fb909SSimon Glass soft_spi_scl(dev, 0);
150623b6386SSimon Glass else
151050fb909SSimon Glass soft_spi_scl(dev, 1);
152623b6386SSimon Glass tmpdin <<= 1;
153102412c4SPeng Fan if ((plat->flags & SPI_MASTER_NO_RX) == 0)
154050fb909SSimon Glass tmpdin |= dm_gpio_get_value(&plat->miso);
155623b6386SSimon Glass tmpdout <<= 1;
156623b6386SSimon Glass udelay(plat->spi_delay_us);
157623b6386SSimon Glass if (cpha)
158050fb909SSimon Glass soft_spi_scl(dev, 1);
159623b6386SSimon Glass }
160623b6386SSimon Glass /*
161623b6386SSimon Glass * If the number of bits isn't a multiple of 8, shift the last
162623b6386SSimon Glass * bits over to left-justify them. Then store the last byte
163623b6386SSimon Glass * read in.
164623b6386SSimon Glass */
165623b6386SSimon Glass if (rxd) {
166623b6386SSimon Glass if ((bitlen % 8) != 0)
167623b6386SSimon Glass tmpdin <<= 8 - (bitlen % 8);
168623b6386SSimon Glass *rxd++ = tmpdin;
169623b6386SSimon Glass }
170623b6386SSimon Glass
171623b6386SSimon Glass if (flags & SPI_XFER_END)
172623b6386SSimon Glass soft_spi_cs_deactivate(dev);
173623b6386SSimon Glass
174623b6386SSimon Glass return 0;
175623b6386SSimon Glass }
176623b6386SSimon Glass
soft_spi_set_speed(struct udevice * dev,unsigned int speed)177623b6386SSimon Glass static int soft_spi_set_speed(struct udevice *dev, unsigned int speed)
178623b6386SSimon Glass {
179623b6386SSimon Glass /* Accept any speed */
180623b6386SSimon Glass return 0;
181623b6386SSimon Glass }
182623b6386SSimon Glass
soft_spi_set_mode(struct udevice * dev,unsigned int mode)183623b6386SSimon Glass static int soft_spi_set_mode(struct udevice *dev, unsigned int mode)
184623b6386SSimon Glass {
185623b6386SSimon Glass struct soft_spi_priv *priv = dev_get_priv(dev);
186623b6386SSimon Glass
187623b6386SSimon Glass priv->mode = mode;
188623b6386SSimon Glass
189623b6386SSimon Glass return 0;
190623b6386SSimon Glass }
191623b6386SSimon Glass
192623b6386SSimon Glass static const struct dm_spi_ops soft_spi_ops = {
193623b6386SSimon Glass .claim_bus = soft_spi_claim_bus,
194623b6386SSimon Glass .release_bus = soft_spi_release_bus,
195623b6386SSimon Glass .xfer = soft_spi_xfer,
196623b6386SSimon Glass .set_speed = soft_spi_set_speed,
197623b6386SSimon Glass .set_mode = soft_spi_set_mode,
198623b6386SSimon Glass };
199623b6386SSimon Glass
soft_spi_ofdata_to_platdata(struct udevice * dev)200623b6386SSimon Glass static int soft_spi_ofdata_to_platdata(struct udevice *dev)
201623b6386SSimon Glass {
202623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata;
203623b6386SSimon Glass const void *blob = gd->fdt_blob;
204e160f7d4SSimon Glass int node = dev_of_offset(dev);
205623b6386SSimon Glass
206623b6386SSimon Glass plat->spi_delay_us = fdtdec_get_int(blob, node, "spi-delay-us", 0);
207623b6386SSimon Glass
208623b6386SSimon Glass return 0;
209623b6386SSimon Glass }
210623b6386SSimon Glass
soft_spi_probe(struct udevice * dev)211623b6386SSimon Glass static int soft_spi_probe(struct udevice *dev)
212623b6386SSimon Glass {
213bcbe3d15SSimon Glass struct spi_slave *slave = dev_get_parent_priv(dev);
214623b6386SSimon Glass struct soft_spi_platdata *plat = dev->platdata;
215050fb909SSimon Glass int cs_flags, clk_flags;
216102412c4SPeng Fan int ret;
217623b6386SSimon Glass
218050fb909SSimon Glass cs_flags = (slave->mode & SPI_CS_HIGH) ? 0 : GPIOD_ACTIVE_LOW;
219050fb909SSimon Glass clk_flags = (slave->mode & SPI_CPOL) ? GPIOD_ACTIVE_LOW : 0;
220102412c4SPeng Fan
221102412c4SPeng Fan if (gpio_request_by_name(dev, "cs-gpios", 0, &plat->cs,
222050fb909SSimon Glass GPIOD_IS_OUT | cs_flags) ||
223102412c4SPeng Fan gpio_request_by_name(dev, "gpio-sck", 0, &plat->sclk,
224102412c4SPeng Fan GPIOD_IS_OUT | clk_flags))
225102412c4SPeng Fan return -EINVAL;
226102412c4SPeng Fan
227102412c4SPeng Fan ret = gpio_request_by_name(dev, "gpio-mosi", 0, &plat->mosi,
228102412c4SPeng Fan GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE);
229102412c4SPeng Fan if (ret)
230102412c4SPeng Fan plat->flags |= SPI_MASTER_NO_TX;
231102412c4SPeng Fan
232102412c4SPeng Fan ret = gpio_request_by_name(dev, "gpio-miso", 0, &plat->miso,
233102412c4SPeng Fan GPIOD_IS_IN);
234102412c4SPeng Fan if (ret)
235102412c4SPeng Fan plat->flags |= SPI_MASTER_NO_RX;
236102412c4SPeng Fan
237102412c4SPeng Fan if ((plat->flags & (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX)) ==
238102412c4SPeng Fan (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX))
239050fb909SSimon Glass return -EINVAL;
240623b6386SSimon Glass
241623b6386SSimon Glass return 0;
242623b6386SSimon Glass }
243623b6386SSimon Glass
244623b6386SSimon Glass static const struct udevice_id soft_spi_ids[] = {
245102412c4SPeng Fan { .compatible = "spi-gpio" },
246623b6386SSimon Glass { }
247623b6386SSimon Glass };
248623b6386SSimon Glass
249623b6386SSimon Glass U_BOOT_DRIVER(soft_spi) = {
250623b6386SSimon Glass .name = "soft_spi",
251623b6386SSimon Glass .id = UCLASS_SPI,
252623b6386SSimon Glass .of_match = soft_spi_ids,
253623b6386SSimon Glass .ops = &soft_spi_ops,
254623b6386SSimon Glass .ofdata_to_platdata = soft_spi_ofdata_to_platdata,
255623b6386SSimon Glass .platdata_auto_alloc_size = sizeof(struct soft_spi_platdata),
256623b6386SSimon Glass .priv_auto_alloc_size = sizeof(struct soft_spi_priv),
257623b6386SSimon Glass .probe = soft_spi_probe,
258623b6386SSimon Glass };
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