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https://github.com/brain-hackers/u-boot-brain
synced 2024-08-20 00:48:52 +09:00
![Simon Glass](/assets/img/avatar_default.png)
At present we go through various contortions to store the SPI slave's chip select in its private data. This only exists when the slave is active so must be set up when it is probed. Until the device is probed we don't actually know what chip select it will appear on. However, now that we can support per-child platform data, we can use that instead. This allows us to set up the chip select when the child is bound, and avoid the messy contortions. Unfortunately this is a fairly large change and it seems to be difficult to break it down further. Signed-off-by: Simon Glass <sjg@chromium.org>
388 lines
8.6 KiB
C
388 lines
8.6 KiB
C
/*
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* Copyright (c) 2014 Google, Inc
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <dm.h>
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#include <errno.h>
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#include <fdtdec.h>
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#include <malloc.h>
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#include <spi.h>
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#include <dm/device-internal.h>
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#include <dm/uclass-internal.h>
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#include <dm/root.h>
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#include <dm/lists.h>
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#include <dm/util.h>
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DECLARE_GLOBAL_DATA_PTR;
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static int spi_set_speed_mode(struct udevice *bus, int speed, int mode)
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{
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struct dm_spi_ops *ops;
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int ret;
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ops = spi_get_ops(bus);
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if (ops->set_speed)
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ret = ops->set_speed(bus, speed);
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else
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ret = -EINVAL;
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if (ret) {
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printf("Cannot set speed (err=%d)\n", ret);
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return ret;
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}
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if (ops->set_mode)
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ret = ops->set_mode(bus, mode);
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else
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ret = -EINVAL;
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if (ret) {
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printf("Cannot set mode (err=%d)\n", ret);
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return ret;
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}
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return 0;
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}
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int spi_claim_bus(struct spi_slave *slave)
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{
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struct udevice *dev = slave->dev;
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struct udevice *bus = dev->parent;
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struct dm_spi_ops *ops = spi_get_ops(bus);
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struct dm_spi_bus *spi = bus->uclass_priv;
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int speed;
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int ret;
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speed = slave->max_hz;
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if (spi->max_hz) {
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if (speed)
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speed = min(speed, (int)spi->max_hz);
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else
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speed = spi->max_hz;
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}
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if (!speed)
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speed = 100000;
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ret = spi_set_speed_mode(bus, speed, slave->mode);
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if (ret)
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return ret;
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return ops->claim_bus ? ops->claim_bus(bus) : 0;
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}
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void spi_release_bus(struct spi_slave *slave)
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{
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struct udevice *dev = slave->dev;
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struct udevice *bus = dev->parent;
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struct dm_spi_ops *ops = spi_get_ops(bus);
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if (ops->release_bus)
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ops->release_bus(bus);
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}
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int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
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const void *dout, void *din, unsigned long flags)
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{
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struct udevice *dev = slave->dev;
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struct udevice *bus = dev->parent;
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if (bus->uclass->uc_drv->id != UCLASS_SPI)
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return -EOPNOTSUPP;
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return spi_get_ops(bus)->xfer(dev, bitlen, dout, din, flags);
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}
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int spi_post_bind(struct udevice *dev)
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{
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/* Scan the bus for devices */
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return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
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}
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int spi_child_post_bind(struct udevice *dev)
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{
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struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
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if (dev->of_offset == -1)
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return 0;
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return spi_slave_ofdata_to_platdata(gd->fdt_blob, dev->of_offset, plat);
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}
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int spi_post_probe(struct udevice *bus)
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{
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struct dm_spi_bus *spi = bus->uclass_priv;
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spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
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"spi-max-frequency", 0);
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return 0;
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}
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int spi_child_pre_probe(struct udevice *dev)
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{
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struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
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struct spi_slave *slave = dev_get_parentdata(dev);
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/*
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* This is needed because we pass struct spi_slave around the place
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* instead slave->dev (a struct udevice). So we have to have some
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* way to access the slave udevice given struct spi_slave. Once we
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* change the SPI API to use udevice instead of spi_slave, we can
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* drop this.
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*/
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slave->dev = dev;
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slave->max_hz = plat->max_hz;
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slave->mode = plat->mode;
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return 0;
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}
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int spi_chip_select(struct udevice *dev)
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{
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struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
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return plat ? plat->cs : -ENOENT;
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}
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int spi_find_chip_select(struct udevice *bus, int cs, struct udevice **devp)
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{
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struct udevice *dev;
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for (device_find_first_child(bus, &dev); dev;
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device_find_next_child(&dev)) {
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struct dm_spi_slave_platdata *plat;
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plat = dev_get_parent_platdata(dev);
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debug("%s: plat=%p, cs=%d\n", __func__, plat, plat->cs);
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if (plat->cs == cs) {
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*devp = dev;
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return 0;
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}
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}
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return -ENODEV;
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}
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int spi_cs_is_valid(unsigned int busnum, unsigned int cs)
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{
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struct spi_cs_info info;
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struct udevice *bus;
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int ret;
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ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
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if (ret) {
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debug("%s: No bus %d\n", __func__, busnum);
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return ret;
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}
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return spi_cs_info(bus, cs, &info);
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}
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int spi_cs_info(struct udevice *bus, uint cs, struct spi_cs_info *info)
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{
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struct spi_cs_info local_info;
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struct dm_spi_ops *ops;
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int ret;
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if (!info)
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info = &local_info;
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/* If there is a device attached, return it */
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info->dev = NULL;
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ret = spi_find_chip_select(bus, cs, &info->dev);
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if (!ret)
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return 0;
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/*
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* Otherwise ask the driver. For the moment we don't have CS info.
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* When we do we could provide the driver with a helper function
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* to figure out what chip selects are valid, or just handle the
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* request.
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*/
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ops = spi_get_ops(bus);
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if (ops->cs_info)
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return ops->cs_info(bus, cs, info);
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/*
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* We could assume there is at least one valid chip select, but best
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* to be sure and return an error in this case. The driver didn't
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* care enough to tell us.
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*/
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return -ENODEV;
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}
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int spi_find_bus_and_cs(int busnum, int cs, struct udevice **busp,
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struct udevice **devp)
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{
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struct udevice *bus, *dev;
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int ret;
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ret = uclass_find_device_by_seq(UCLASS_SPI, busnum, false, &bus);
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if (ret) {
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debug("%s: No bus %d\n", __func__, busnum);
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return ret;
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}
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ret = spi_find_chip_select(bus, cs, &dev);
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if (ret) {
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debug("%s: No cs %d\n", __func__, cs);
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return ret;
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}
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*busp = bus;
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*devp = dev;
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return ret;
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}
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int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode,
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const char *drv_name, const char *dev_name,
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struct udevice **busp, struct spi_slave **devp)
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{
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struct udevice *bus, *dev;
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bool created = false;
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int ret;
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ret = uclass_get_device_by_seq(UCLASS_SPI, busnum, &bus);
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if (ret) {
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printf("Invalid bus %d (err=%d)\n", busnum, ret);
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return ret;
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}
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ret = spi_find_chip_select(bus, cs, &dev);
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/*
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* If there is no such device, create one automatically. This means
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* that we don't need a device tree node or platform data for the
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* SPI flash chip - we will bind to the correct driver.
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*/
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if (ret == -ENODEV && drv_name) {
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struct dm_spi_slave_platdata *plat;
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debug("%s: Binding new device '%s', busnum=%d, cs=%d, driver=%s\n",
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__func__, dev_name, busnum, cs, drv_name);
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ret = device_bind_driver(bus, drv_name, dev_name, &dev);
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if (ret)
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return ret;
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plat = dev_get_parent_platdata(dev);
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plat->cs = cs;
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plat->max_hz = speed;
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plat->mode = mode;
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created = true;
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} else if (ret) {
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printf("Invalid chip select %d:%d (err=%d)\n", busnum, cs,
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ret);
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return ret;
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}
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if (!device_active(dev)) {
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struct spi_slave *slave;
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ret = device_probe(dev);
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if (ret)
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goto err;
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slave = dev_get_parentdata(dev);
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slave->dev = dev;
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}
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ret = spi_set_speed_mode(bus, speed, mode);
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if (ret)
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goto err;
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*busp = bus;
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*devp = dev_get_parentdata(dev);
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debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
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return 0;
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err:
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debug("%s: Error path, credted=%d, device '%s'\n", __func__,
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created, dev->name);
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if (created) {
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device_remove(dev);
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device_unbind(dev);
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}
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return ret;
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}
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/* Compatibility function - to be removed */
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struct spi_slave *spi_setup_slave_fdt(const void *blob, int node,
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int bus_node)
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{
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struct udevice *bus, *dev;
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int ret;
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ret = uclass_get_device_by_of_offset(UCLASS_SPI, bus_node, &bus);
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if (ret)
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return NULL;
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ret = device_get_child_by_of_offset(bus, node, &dev);
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if (ret)
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return NULL;
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return dev_get_parentdata(dev);
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}
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/* Compatibility function - to be removed */
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struct spi_slave *spi_setup_slave(unsigned int busnum, unsigned int cs,
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unsigned int speed, unsigned int mode)
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{
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struct spi_slave *slave;
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struct udevice *dev;
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int ret;
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ret = spi_get_bus_and_cs(busnum, cs, speed, mode, NULL, 0, &dev,
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&slave);
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if (ret)
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return NULL;
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return slave;
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}
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void spi_free_slave(struct spi_slave *slave)
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{
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device_remove(slave->dev);
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slave->dev = NULL;
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}
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int spi_slave_ofdata_to_platdata(const void *blob, int node,
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struct dm_spi_slave_platdata *plat)
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{
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int mode = 0;
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plat->cs = fdtdec_get_int(blob, node, "reg", -1);
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plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
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if (fdtdec_get_bool(blob, node, "spi-cpol"))
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mode |= SPI_CPOL;
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if (fdtdec_get_bool(blob, node, "spi-cpha"))
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mode |= SPI_CPHA;
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if (fdtdec_get_bool(blob, node, "spi-cs-high"))
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mode |= SPI_CS_HIGH;
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if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
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mode |= SPI_PREAMBLE;
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plat->mode = mode;
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return 0;
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}
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UCLASS_DRIVER(spi) = {
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.id = UCLASS_SPI,
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.name = "spi",
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.flags = DM_UC_FLAG_SEQ_ALIAS,
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.post_bind = spi_post_bind,
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.post_probe = spi_post_probe,
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.child_pre_probe = spi_child_pre_probe,
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.per_device_auto_alloc_size = sizeof(struct dm_spi_bus),
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.per_child_auto_alloc_size = sizeof(struct spi_slave),
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.per_child_platdata_auto_alloc_size =
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sizeof(struct dm_spi_slave_platdata),
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.child_post_bind = spi_child_post_bind,
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};
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UCLASS_DRIVER(spi_generic) = {
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.id = UCLASS_SPI_GENERIC,
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.name = "spi_generic",
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};
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U_BOOT_DRIVER(spi_generic_drv) = {
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.name = "spi_generic_drv",
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.id = UCLASS_SPI_GENERIC,
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};
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