Tom Rini | 83d290c | 2018-05-06 17:58:06 -0400 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (c) 2014 Google, Inc |
| 4 | * |
| 5 | * (C) Copyright 2002 |
| 6 | * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com. |
| 7 | * |
| 8 | * Influenced by code from: |
| 9 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 10 | */ |
| 11 | |
| 12 | #include <common.h> |
| 13 | #include <dm.h> |
| 14 | #include <errno.h> |
| 15 | #include <fdtdec.h> |
Simon Glass | f7ae49f | 2020-05-10 11:40:05 -0600 | [diff] [blame] | 16 | #include <log.h> |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 17 | #include <malloc.h> |
| 18 | #include <spi.h> |
| 19 | #include <asm/gpio.h> |
Simon Glass | c05ed00 | 2020-05-10 11:40:11 -0600 | [diff] [blame^] | 20 | #include <linux/delay.h> |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 21 | |
| 22 | DECLARE_GLOBAL_DATA_PTR; |
| 23 | |
| 24 | struct soft_spi_platdata { |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 25 | struct gpio_desc cs; |
| 26 | struct gpio_desc sclk; |
| 27 | struct gpio_desc mosi; |
| 28 | struct gpio_desc miso; |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 29 | int spi_delay_us; |
Peng Fan | 102412c | 2016-05-03 10:02:21 +0800 | [diff] [blame] | 30 | int flags; |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 31 | }; |
| 32 | |
Peng Fan | 102412c | 2016-05-03 10:02:21 +0800 | [diff] [blame] | 33 | #define SPI_MASTER_NO_RX BIT(0) |
| 34 | #define SPI_MASTER_NO_TX BIT(1) |
| 35 | |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 36 | struct soft_spi_priv { |
| 37 | unsigned int mode; |
| 38 | }; |
| 39 | |
| 40 | static int soft_spi_scl(struct udevice *dev, int bit) |
| 41 | { |
Peng Fan | b6d54d5 | 2016-05-03 10:02:20 +0800 | [diff] [blame] | 42 | struct udevice *bus = dev_get_parent(dev); |
| 43 | struct soft_spi_platdata *plat = dev_get_platdata(bus); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 44 | |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 45 | dm_gpio_set_value(&plat->sclk, bit); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 46 | |
| 47 | return 0; |
| 48 | } |
| 49 | |
| 50 | static int soft_spi_sda(struct udevice *dev, int bit) |
| 51 | { |
Peng Fan | b6d54d5 | 2016-05-03 10:02:20 +0800 | [diff] [blame] | 52 | struct udevice *bus = dev_get_parent(dev); |
| 53 | struct soft_spi_platdata *plat = dev_get_platdata(bus); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 54 | |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 55 | dm_gpio_set_value(&plat->mosi, bit); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 56 | |
| 57 | return 0; |
| 58 | } |
| 59 | |
| 60 | static int soft_spi_cs_activate(struct udevice *dev) |
| 61 | { |
Peng Fan | b6d54d5 | 2016-05-03 10:02:20 +0800 | [diff] [blame] | 62 | struct udevice *bus = dev_get_parent(dev); |
| 63 | struct soft_spi_platdata *plat = dev_get_platdata(bus); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 64 | |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 65 | dm_gpio_set_value(&plat->cs, 0); |
| 66 | dm_gpio_set_value(&plat->sclk, 0); |
| 67 | dm_gpio_set_value(&plat->cs, 1); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 68 | |
| 69 | return 0; |
| 70 | } |
| 71 | |
| 72 | static int soft_spi_cs_deactivate(struct udevice *dev) |
| 73 | { |
Peng Fan | b6d54d5 | 2016-05-03 10:02:20 +0800 | [diff] [blame] | 74 | struct udevice *bus = dev_get_parent(dev); |
| 75 | struct soft_spi_platdata *plat = dev_get_platdata(bus); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 76 | |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 77 | dm_gpio_set_value(&plat->cs, 0); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 78 | |
| 79 | return 0; |
| 80 | } |
| 81 | |
| 82 | static int soft_spi_claim_bus(struct udevice *dev) |
| 83 | { |
| 84 | /* |
| 85 | * Make sure the SPI clock is in idle state as defined for |
| 86 | * this slave. |
| 87 | */ |
| 88 | return soft_spi_scl(dev, 0); |
| 89 | } |
| 90 | |
| 91 | static int soft_spi_release_bus(struct udevice *dev) |
| 92 | { |
| 93 | /* Nothing to do */ |
| 94 | return 0; |
| 95 | } |
| 96 | |
| 97 | /*----------------------------------------------------------------------- |
| 98 | * SPI transfer |
| 99 | * |
| 100 | * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks |
| 101 | * "bitlen" bits in the SPI MISO port. That's just the way SPI works. |
| 102 | * |
| 103 | * The source of the outgoing bits is the "dout" parameter and the |
| 104 | * destination of the input bits is the "din" parameter. Note that "dout" |
| 105 | * and "din" can point to the same memory location, in which case the |
| 106 | * input data overwrites the output data (since both are buffered by |
| 107 | * temporary variables, this is OK). |
| 108 | */ |
| 109 | static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen, |
| 110 | const void *dout, void *din, unsigned long flags) |
| 111 | { |
Peng Fan | b6d54d5 | 2016-05-03 10:02:20 +0800 | [diff] [blame] | 112 | struct udevice *bus = dev_get_parent(dev); |
| 113 | struct soft_spi_priv *priv = dev_get_priv(bus); |
| 114 | struct soft_spi_platdata *plat = dev_get_platdata(bus); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 115 | uchar tmpdin = 0; |
| 116 | uchar tmpdout = 0; |
| 117 | const u8 *txd = dout; |
| 118 | u8 *rxd = din; |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 119 | int cpha = priv->mode & SPI_CPHA; |
| 120 | unsigned int j; |
| 121 | |
| 122 | debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n", |
| 123 | dev->parent->name, dev->name, *(uint *)txd, *(uint *)rxd, |
| 124 | bitlen); |
| 125 | |
| 126 | if (flags & SPI_XFER_BEGIN) |
| 127 | soft_spi_cs_activate(dev); |
| 128 | |
| 129 | for (j = 0; j < bitlen; j++) { |
| 130 | /* |
| 131 | * Check if it is time to work on a new byte. |
| 132 | */ |
| 133 | if ((j % 8) == 0) { |
| 134 | if (txd) |
| 135 | tmpdout = *txd++; |
| 136 | else |
| 137 | tmpdout = 0; |
| 138 | if (j != 0) { |
| 139 | if (rxd) |
| 140 | *rxd++ = tmpdin; |
| 141 | } |
| 142 | tmpdin = 0; |
| 143 | } |
| 144 | |
| 145 | if (!cpha) |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 146 | soft_spi_scl(dev, 0); |
Peng Fan | 102412c | 2016-05-03 10:02:21 +0800 | [diff] [blame] | 147 | if ((plat->flags & SPI_MASTER_NO_TX) == 0) |
| 148 | soft_spi_sda(dev, !!(tmpdout & 0x80)); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 149 | udelay(plat->spi_delay_us); |
| 150 | if (cpha) |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 151 | soft_spi_scl(dev, 0); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 152 | else |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 153 | soft_spi_scl(dev, 1); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 154 | tmpdin <<= 1; |
Peng Fan | 102412c | 2016-05-03 10:02:21 +0800 | [diff] [blame] | 155 | if ((plat->flags & SPI_MASTER_NO_RX) == 0) |
| 156 | tmpdin |= dm_gpio_get_value(&plat->miso); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 157 | tmpdout <<= 1; |
| 158 | udelay(plat->spi_delay_us); |
| 159 | if (cpha) |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 160 | soft_spi_scl(dev, 1); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 161 | } |
| 162 | /* |
| 163 | * If the number of bits isn't a multiple of 8, shift the last |
| 164 | * bits over to left-justify them. Then store the last byte |
| 165 | * read in. |
| 166 | */ |
| 167 | if (rxd) { |
| 168 | if ((bitlen % 8) != 0) |
| 169 | tmpdin <<= 8 - (bitlen % 8); |
| 170 | *rxd++ = tmpdin; |
| 171 | } |
| 172 | |
| 173 | if (flags & SPI_XFER_END) |
| 174 | soft_spi_cs_deactivate(dev); |
| 175 | |
| 176 | return 0; |
| 177 | } |
| 178 | |
| 179 | static int soft_spi_set_speed(struct udevice *dev, unsigned int speed) |
| 180 | { |
| 181 | /* Accept any speed */ |
| 182 | return 0; |
| 183 | } |
| 184 | |
| 185 | static int soft_spi_set_mode(struct udevice *dev, unsigned int mode) |
| 186 | { |
| 187 | struct soft_spi_priv *priv = dev_get_priv(dev); |
| 188 | |
| 189 | priv->mode = mode; |
| 190 | |
| 191 | return 0; |
| 192 | } |
| 193 | |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 194 | static const struct dm_spi_ops soft_spi_ops = { |
| 195 | .claim_bus = soft_spi_claim_bus, |
| 196 | .release_bus = soft_spi_release_bus, |
| 197 | .xfer = soft_spi_xfer, |
| 198 | .set_speed = soft_spi_set_speed, |
| 199 | .set_mode = soft_spi_set_mode, |
| 200 | }; |
| 201 | |
| 202 | static int soft_spi_ofdata_to_platdata(struct udevice *dev) |
| 203 | { |
| 204 | struct soft_spi_platdata *plat = dev->platdata; |
| 205 | const void *blob = gd->fdt_blob; |
Simon Glass | e160f7d | 2017-01-17 16:52:55 -0700 | [diff] [blame] | 206 | int node = dev_of_offset(dev); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 207 | |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 208 | plat->spi_delay_us = fdtdec_get_int(blob, node, "spi-delay-us", 0); |
| 209 | |
| 210 | return 0; |
| 211 | } |
| 212 | |
| 213 | static int soft_spi_probe(struct udevice *dev) |
| 214 | { |
Simon Glass | bcbe3d1 | 2015-09-28 23:32:01 -0600 | [diff] [blame] | 215 | struct spi_slave *slave = dev_get_parent_priv(dev); |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 216 | struct soft_spi_platdata *plat = dev->platdata; |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 217 | int cs_flags, clk_flags; |
Peng Fan | 102412c | 2016-05-03 10:02:21 +0800 | [diff] [blame] | 218 | int ret; |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 219 | |
Christophe Kerello | dfe72d0 | 2019-08-02 15:46:29 +0200 | [diff] [blame] | 220 | cs_flags = (slave && slave->mode & SPI_CS_HIGH) ? 0 : GPIOD_ACTIVE_LOW; |
| 221 | clk_flags = (slave && slave->mode & SPI_CPOL) ? GPIOD_ACTIVE_LOW : 0; |
Peng Fan | 102412c | 2016-05-03 10:02:21 +0800 | [diff] [blame] | 222 | |
| 223 | if (gpio_request_by_name(dev, "cs-gpios", 0, &plat->cs, |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 224 | GPIOD_IS_OUT | cs_flags) || |
Peng Fan | 102412c | 2016-05-03 10:02:21 +0800 | [diff] [blame] | 225 | gpio_request_by_name(dev, "gpio-sck", 0, &plat->sclk, |
| 226 | GPIOD_IS_OUT | clk_flags)) |
| 227 | return -EINVAL; |
| 228 | |
| 229 | ret = gpio_request_by_name(dev, "gpio-mosi", 0, &plat->mosi, |
| 230 | GPIOD_IS_OUT | GPIOD_IS_OUT_ACTIVE); |
| 231 | if (ret) |
| 232 | plat->flags |= SPI_MASTER_NO_TX; |
| 233 | |
| 234 | ret = gpio_request_by_name(dev, "gpio-miso", 0, &plat->miso, |
| 235 | GPIOD_IS_IN); |
| 236 | if (ret) |
| 237 | plat->flags |= SPI_MASTER_NO_RX; |
| 238 | |
| 239 | if ((plat->flags & (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX)) == |
| 240 | (SPI_MASTER_NO_RX | SPI_MASTER_NO_TX)) |
Simon Glass | 050fb90 | 2015-01-05 20:05:40 -0700 | [diff] [blame] | 241 | return -EINVAL; |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 242 | |
| 243 | return 0; |
| 244 | } |
| 245 | |
| 246 | static const struct udevice_id soft_spi_ids[] = { |
Peng Fan | 102412c | 2016-05-03 10:02:21 +0800 | [diff] [blame] | 247 | { .compatible = "spi-gpio" }, |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 248 | { } |
| 249 | }; |
| 250 | |
| 251 | U_BOOT_DRIVER(soft_spi) = { |
| 252 | .name = "soft_spi", |
| 253 | .id = UCLASS_SPI, |
| 254 | .of_match = soft_spi_ids, |
| 255 | .ops = &soft_spi_ops, |
| 256 | .ofdata_to_platdata = soft_spi_ofdata_to_platdata, |
| 257 | .platdata_auto_alloc_size = sizeof(struct soft_spi_platdata), |
| 258 | .priv_auto_alloc_size = sizeof(struct soft_spi_priv), |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 259 | .probe = soft_spi_probe, |
Simon Glass | 623b638 | 2014-10-13 23:42:00 -0600 | [diff] [blame] | 260 | }; |