Merge tag 'xilinx-for-v2023.01-rc3' of https://source.denx.de/u-boot/custodians/u...

[platform/kernel/u-boot.git] / drivers / spi / soft_spi.c

diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c
index d23dc81..f3602a2 100644 (file)
--- a/drivers/spi/soft_spi.c
+++ b/drivers/spi/soft_spi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (c) 2014 Google, Inc
  *
@@ -6,21 +7,23 @@
  *
  * Influenced by code from:
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
- *
- * SPDX-License-Identifier:    GPL-2.0+
  */
 
 #include <common.h>
 #include <dm.h>
 #include <errno.h>
 #include <fdtdec.h>
+#include <log.h>
 #include <malloc.h>
 #include <spi.h>
+#include <asm/global_data.h>
 #include <asm/gpio.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
-struct soft_spi_platdata {
+struct soft_spi_plat {
        struct gpio_desc cs;
        struct gpio_desc sclk;
        struct gpio_desc mosi;
@@ -39,7 +42,7 @@ struct soft_spi_priv {
 static int soft_spi_scl(struct udevice *dev, int bit)
 {
        struct udevice *bus = dev_get_parent(dev);
-       struct soft_spi_platdata *plat = dev_get_platdata(bus);
+       struct soft_spi_plat *plat = dev_get_plat(bus);
 
        dm_gpio_set_value(&plat->sclk, bit);
 
@@ -49,7 +52,7 @@ static int soft_spi_scl(struct udevice *dev, int bit)
 static int soft_spi_sda(struct udevice *dev, int bit)
 {
        struct udevice *bus = dev_get_parent(dev);
-       struct soft_spi_platdata *plat = dev_get_platdata(bus);
+       struct soft_spi_plat *plat = dev_get_plat(bus);
 
        dm_gpio_set_value(&plat->mosi, bit);
 
@@ -59,10 +62,12 @@ static int soft_spi_sda(struct udevice *dev, int bit)
 static int soft_spi_cs_activate(struct udevice *dev)
 {
        struct udevice *bus = dev_get_parent(dev);
-       struct soft_spi_platdata *plat = dev_get_platdata(bus);
+       struct soft_spi_priv *priv = dev_get_priv(bus);
+       struct soft_spi_plat *plat = dev_get_plat(bus);
+       int cidle = !!(priv->mode & SPI_CPOL);
 
        dm_gpio_set_value(&plat->cs, 0);
-       dm_gpio_set_value(&plat->sclk, 0);
+       dm_gpio_set_value(&plat->sclk, cidle); /* to idle */
        dm_gpio_set_value(&plat->cs, 1);
 
        return 0;
@@ -71,7 +76,7 @@ static int soft_spi_cs_activate(struct udevice *dev)
 static int soft_spi_cs_deactivate(struct udevice *dev)
 {
        struct udevice *bus = dev_get_parent(dev);
-       struct soft_spi_platdata *plat = dev_get_platdata(bus);
+       struct soft_spi_plat *plat = dev_get_plat(bus);
 
        dm_gpio_set_value(&plat->cs, 0);
 
@@ -80,11 +85,14 @@ static int soft_spi_cs_deactivate(struct udevice *dev)
 
 static int soft_spi_claim_bus(struct udevice *dev)
 {
+       struct udevice *bus = dev_get_parent(dev);
+       struct soft_spi_priv *priv = dev_get_priv(bus);
+       int cidle = !!(priv->mode & SPI_CPOL);
        /*
         * Make sure the SPI clock is in idle state as defined for
         * this slave.
         */
-       return soft_spi_scl(dev, 0);
+       return soft_spi_scl(dev, cidle);
 }
 
 static int soft_spi_release_bus(struct udevice *dev)
@@ -110,12 +118,13 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
 {
        struct udevice *bus = dev_get_parent(dev);
        struct soft_spi_priv *priv = dev_get_priv(bus);
-       struct soft_spi_platdata *plat = dev_get_platdata(bus);
+       struct soft_spi_plat *plat = dev_get_plat(bus);
        uchar           tmpdin  = 0;
        uchar           tmpdout = 0;
        const u8        *txd = dout;
        u8              *rxd = din;
-       int             cpha = priv->mode & SPI_CPHA;
+       int             cpha = !!(priv->mode & SPI_CPHA);
+       int             cidle = !!(priv->mode & SPI_CPOL);
        unsigned int    j;
 
        debug("spi_xfer: slave %s:%s dout %08X din %08X bitlen %u\n",
@@ -141,22 +150,42 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
                        tmpdin  = 0;
                }
 
-               if (!cpha)
-                       soft_spi_scl(dev, 0);
+               /*
+                * CPOL 0: idle is low (0), active is high (1)
+                * CPOL 1: idle is high (1), active is low (0)
+                */
+
+               /*
+                * drive bit
+                *  CPHA 1: CLK from idle to active
+                */
+               if (cpha)
+                       soft_spi_scl(dev, !cidle);
                if ((plat->flags & SPI_MASTER_NO_TX) == 0)
                        soft_spi_sda(dev, !!(tmpdout & 0x80));
                udelay(plat->spi_delay_us);
-               if (cpha)
-                       soft_spi_scl(dev, 0);
+
+               /*
+                * sample bit
+                *  CPHA 0: CLK from idle to active
+                *  CPHA 1: CLK from active to idle
+                */
+               if (!cpha)
+                       soft_spi_scl(dev, !cidle);
                else
-                       soft_spi_scl(dev, 1);
+                       soft_spi_scl(dev, cidle);
                tmpdin  <<= 1;
                if ((plat->flags & SPI_MASTER_NO_RX) == 0)
                        tmpdin  |= dm_gpio_get_value(&plat->miso);
                tmpdout <<= 1;
                udelay(plat->spi_delay_us);
-               if (cpha)
-                       soft_spi_scl(dev, 1);
+
+               /*
+                * drive bit
+                *  CPHA 0: CLK from active to idle
+                */
+               if (!cpha)
+                       soft_spi_scl(dev, cidle);
        }
        /*
         * If the number of bits isn't a multiple of 8, shift the last
@@ -177,7 +206,7 @@ static int soft_spi_xfer(struct udevice *dev, unsigned int bitlen,
 
 static int soft_spi_set_speed(struct udevice *dev, unsigned int speed)
 {
-       /* Accept any speed */
+       /* Ignore any speed settings. Speed is implemented via "spi-delay-us" */
        return 0;
 }
 
@@ -198,11 +227,11 @@ static const struct dm_spi_ops soft_spi_ops = {
        .set_mode       = soft_spi_set_mode,
 };
 
-static int soft_spi_ofdata_to_platdata(struct udevice *dev)
+static int soft_spi_of_to_plat(struct udevice *dev)
 {
-       struct soft_spi_platdata *plat = dev->platdata;
+       struct soft_spi_plat *plat = dev_get_plat(dev);
        const void *blob = gd->fdt_blob;
-       int node = dev->of_offset;
+       int node = dev_of_offset(dev);
 
        plat->spi_delay_us = fdtdec_get_int(blob, node, "spi-delay-us", 0);
 
@@ -212,12 +241,12 @@ static int soft_spi_ofdata_to_platdata(struct udevice *dev)
 static int soft_spi_probe(struct udevice *dev)
 {
        struct spi_slave *slave = dev_get_parent_priv(dev);
-       struct soft_spi_platdata *plat = dev->platdata;
+       struct soft_spi_plat *plat = dev_get_plat(dev);
        int cs_flags, clk_flags;
        int ret;
 
-       cs_flags = (slave->mode & SPI_CS_HIGH) ? 0 : GPIOD_ACTIVE_LOW;
-       clk_flags = (slave->mode & SPI_CPOL) ? GPIOD_ACTIVE_LOW : 0;
+       cs_flags = (slave && slave->mode & SPI_CS_HIGH) ? 0 : GPIOD_ACTIVE_LOW;
+       clk_flags = (slave && slave->mode & SPI_CPOL) ? GPIOD_ACTIVE_LOW : 0;
 
        if (gpio_request_by_name(dev, "cs-gpios", 0, &plat->cs,
                                 GPIOD_IS_OUT | cs_flags) ||
@@ -252,8 +281,8 @@ U_BOOT_DRIVER(soft_spi) = {
        .id     = UCLASS_SPI,
        .of_match = soft_spi_ids,
        .ops    = &soft_spi_ops,
-       .ofdata_to_platdata = soft_spi_ofdata_to_platdata,
-       .platdata_auto_alloc_size = sizeof(struct soft_spi_platdata),
-       .priv_auto_alloc_size = sizeof(struct soft_spi_priv),
+       .of_to_plat = soft_spi_of_to_plat,
+       .plat_auto      = sizeof(struct soft_spi_plat),
+       .priv_auto      = sizeof(struct soft_spi_priv),
        .probe  = soft_spi_probe,
 };