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path: root/kernel/arch/powerpc/boot/libfdt-wrapper.c
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/*
 * This file does the necessary interface mapping between the bootwrapper
 * device tree operations and the interface provided by shared source
 * files flatdevicetree.[ch].
 *
 * Copyright 2007 David Gibson, IBM Corporation.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */

#include <stddef.h>
#include <stdio.h>
#include <page.h>
#include <libfdt.h>
#include "ops.h"

#define DEBUG	0
#define BAD_ERROR(err)	(((err) < 0) \
			 && ((err) != -FDT_ERR_NOTFOUND) \
			 && ((err) != -FDT_ERR_EXISTS))

#define check_err(err) \
	({ \
		if (BAD_ERROR(err) || ((err < 0) && DEBUG)) \
			printf("%s():%d  %s\n\r", __func__, __LINE__, \
			       fdt_strerror(err)); \
		if (BAD_ERROR(err)) \
			exit(); \
		(err < 0) ? -1 : 0; \
	})

#define offset_devp(off)	\
	({ \
		unsigned long _offset = (off); \
		check_err(_offset) ? NULL : (void *)(_offset+1); \
	})

#define devp_offset_find(devp)	(((unsigned long)(devp))-1)
#define devp_offset(devp)	(devp ? ((unsigned long)(devp))-1 : 0)

static void *fdt;
static void *buf; /* = NULL */

#define EXPAND_GRANULARITY	1024

static void expand_buf(int minexpand)
{
	int size = fdt_totalsize(fdt);
	int rc;

	size = _ALIGN(size + minexpand, EXPAND_GRANULARITY);
	buf = platform_ops.realloc(buf, size);
	if (!buf)
		fatal("Couldn't find %d bytes to expand device tree\n\r", size);
	rc = fdt_open_into(fdt, buf, size);
	if (rc != 0)
		fatal("Couldn't expand fdt into new buffer: %s\n\r",
		      fdt_strerror(rc));

	fdt = buf;
}

static void *fdt_wrapper_finddevice(const char *path)
{
	return offset_devp(fdt_path_offset(fdt, path));
}

static int fdt_wrapper_getprop(const void *devp, const char *name,
			       void *buf, const int buflen)
{
	const void *p;
	int len;

	p = fdt_getprop(fdt, devp_offset(devp), name, &len);
	if (!p)
		return check_err(len);
	memcpy(buf, p, min(len, buflen));
	return len;
}

static int fdt_wrapper_setprop(const void *devp, const char *name,
			       const void *buf, const int len)
{
	int rc;

	rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
	if (rc == -FDT_ERR_NOSPACE) {
		expand_buf(len + 16);
		rc = fdt_setprop(fdt, devp_offset(devp), name, buf, len);
	}

	return check_err(rc);
}

static int fdt_wrapper_del_node(const void *devp)
{
	return fdt_del_node(fdt, devp_offset(devp));
}

static void *fdt_wrapper_get_parent(const void *devp)
{
	return offset_devp(fdt_parent_offset(fdt, devp_offset(devp)));
}

static void *fdt_wrapper_create_node(const void *devp, const char *name)
{
	int offset;

	offset = fdt_add_subnode(fdt, devp_offset(devp), name);
	if (offset == -FDT_ERR_NOSPACE) {
		expand_buf(strlen(name) + 16);
		offset = fdt_add_subnode(fdt, devp_offset(devp), name);
	}

	return offset_devp(offset);
}

static void *fdt_wrapper_find_node_by_prop_value(const void *prev,
						 const char *name,
						 const char *val,
						 int len)
{
	int offset = fdt_node_offset_by_prop_value(fdt, devp_offset_find(prev),
	                                           name, val, len);
	return offset_devp(offset);
}

static void *fdt_wrapper_find_node_by_compatible(const void *prev,
						 const char *val)
{
	int offset = fdt_node_offset_by_compatible(fdt, devp_offset_find(prev),
	                                           val);
	return offset_devp(offset);
}

static char *fdt_wrapper_get_path(const void *devp, char *buf, int len)
{
	int rc;

	rc = fdt_get_path(fdt, devp_offset(devp), buf, len);
	if (check_err(rc))
		return NULL;
	return buf;
}

static unsigned long fdt_wrapper_finalize(void)
{
	int rc;

	rc = fdt_pack(fdt);
	if (rc != 0)
		fatal("Couldn't pack flat tree: %s\n\r",
		      fdt_strerror(rc));
	return (unsigned long)fdt;
}

void fdt_init(void *blob)
{
	int err;
	int bufsize;

	dt_ops.finddevice = fdt_wrapper_finddevice;
	dt_ops.getprop = fdt_wrapper_getprop;
	dt_ops.setprop = fdt_wrapper_setprop;
	dt_ops.get_parent = fdt_wrapper_get_parent;
	dt_ops.create_node = fdt_wrapper_create_node;
	dt_ops.find_node_by_prop_value = fdt_wrapper_find_node_by_prop_value;
	dt_ops.find_node_by_compatible = fdt_wrapper_find_node_by_compatible;
	dt_ops.del_node = fdt_wrapper_del_node;
	dt_ops.get_path = fdt_wrapper_get_path;
	dt_ops.finalize = fdt_wrapper_finalize;

	/* Make sure the dt blob is the right version and so forth */
	fdt = blob;
	bufsize = fdt_totalsize(fdt) + EXPAND_GRANULARITY;
	buf = malloc(bufsize);
	if(!buf)
		fatal("malloc failed. can't relocate the device tree\n\r");

	err = fdt_open_into(fdt, buf, bufsize);

	if (err != 0)
		fatal("fdt_init(): %s\n\r", fdt_strerror(err));

	fdt = buf;
}
an class="k">struct spi_transfer *t) { struct spi_st *spi_st = spi_master_get_devdata(master); uint32_t ctl = 0; /* Setup transfer */ spi_st->tx_ptr = t->tx_buf; spi_st->rx_ptr = t->rx_buf; if (spi->bits_per_word > 8) { /* * Anything greater than 8 bits-per-word requires 2 * bytes-per-word in the RX/TX buffers */ spi_st->bytes_per_word = 2; spi_st->words_remaining = t->len / 2; } else if (spi->bits_per_word == 8 && !(t->len & 0x1)) { /* * If transfer is even-length, and 8 bits-per-word, then * implement as half-length 16 bits-per-word transfer */ spi_st->bytes_per_word = 2; spi_st->words_remaining = t->len / 2; /* Set SSC_CTL to 16 bits-per-word */ ctl = readl_relaxed(spi_st->base + SSC_CTL); writel_relaxed((ctl | 0xf), spi_st->base + SSC_CTL); readl_relaxed(spi_st->base + SSC_RBUF); } else { spi_st->bytes_per_word = 1; spi_st->words_remaining = t->len; } reinit_completion(&spi_st->done); /* Start transfer by writing to the TX FIFO */ ssc_write_tx_fifo(spi_st); writel_relaxed(SSC_IEN_TEEN, spi_st->base + SSC_IEN); /* Wait for transfer to complete */ wait_for_completion(&spi_st->done); /* Restore SSC_CTL if necessary */ if (ctl) writel_relaxed(ctl, spi_st->base + SSC_CTL); spi_finalize_current_transfer(spi->master); return t->len; } static void spi_st_cleanup(struct spi_device *spi) { int cs = spi->cs_gpio; if (gpio_is_valid(cs)) devm_gpio_free(&spi->dev, cs); } /* the spi->mode bits understood by this driver: */ #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_LOOP | SPI_CS_HIGH) static int spi_st_setup(struct spi_device *spi) { struct spi_st *spi_st = spi_master_get_devdata(spi->master); u32 spi_st_clk, sscbrg, var; u32 hz = spi->max_speed_hz; int cs = spi->cs_gpio; int ret; if (!hz) { dev_err(&spi->dev, "max_speed_hz unspecified\n"); return -EINVAL; } if (!gpio_is_valid(cs)) { dev_err(&spi->dev, "%d is not a valid gpio\n", cs); return -EINVAL; } if (devm_gpio_request(&spi->dev, cs, dev_name(&spi->dev))) { dev_err(&spi->dev, "could not request gpio:%d\n", cs); return -EINVAL; } ret = gpio_direction_output(cs, spi->mode & SPI_CS_HIGH); if (ret) return ret; spi_st_clk = clk_get_rate(spi_st->clk); /* Set SSC_BRF */ sscbrg = spi_st_clk / (2 * hz); if (sscbrg < 0x07 || sscbrg > BIT(16)) { dev_err(&spi->dev, "baudrate %d outside valid range %d\n", sscbrg, hz); return -EINVAL; } spi_st->baud = spi_st_clk / (2 * sscbrg); if (sscbrg == BIT(16)) /* 16-bit counter wraps */ sscbrg = 0x0; writel_relaxed(sscbrg, spi_st->base + SSC_BRG); dev_dbg(&spi->dev, "setting baudrate:target= %u hz, actual= %u hz, sscbrg= %u\n", hz, spi_st->baud, sscbrg); /* Set SSC_CTL and enable SSC */ var = readl_relaxed(spi_st->base + SSC_CTL); var |= SSC_CTL_MS; if (spi->mode & SPI_CPOL) var |= SSC_CTL_PO; else var &= ~SSC_CTL_PO; if (spi->mode & SPI_CPHA) var |= SSC_CTL_PH; else var &= ~SSC_CTL_PH; if ((spi->mode & SPI_LSB_FIRST) == 0) var |= SSC_CTL_HB; else var &= ~SSC_CTL_HB; if (spi->mode & SPI_LOOP) var |= SSC_CTL_LPB; else var &= ~SSC_CTL_LPB; var &= ~SSC_CTL_DATA_WIDTH_MSK; var |= (spi->bits_per_word - 1); var |= SSC_CTL_EN_TX_FIFO | SSC_CTL_EN_RX_FIFO; var |= SSC_CTL_EN; writel_relaxed(var, spi_st->base + SSC_CTL); /* Clear the status register */ readl_relaxed(spi_st->base + SSC_RBUF); return 0; } /* Interrupt fired when TX shift register becomes empty */ static irqreturn_t spi_st_irq(int irq, void *dev_id) { struct spi_st *spi_st = (struct spi_st *)dev_id; /* Read RX FIFO */ ssc_read_rx_fifo(spi_st); /* Fill TX FIFO */ if (spi_st->words_remaining) { ssc_write_tx_fifo(spi_st); } else { /* TX/RX complete */ writel_relaxed(0x0, spi_st->base + SSC_IEN); /* * read SSC_IEN to ensure that this bit is set * before re-enabling interrupt */ readl(spi_st->base + SSC_IEN); complete(&spi_st->done); } return IRQ_HANDLED; } static int spi_st_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct spi_master *master; struct resource *res; struct spi_st *spi_st; int irq, ret = 0; u32 var; master = spi_alloc_master(&pdev->dev, sizeof(*spi_st)); if (!master) return -ENOMEM; master->dev.of_node = np; master->mode_bits = MODEBITS; master->setup = spi_st_setup; master->cleanup = spi_st_cleanup; master->transfer_one = spi_st_transfer_one; master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16); master->auto_runtime_pm = true; master->bus_num = pdev->id; spi_st = spi_master_get_devdata(master); spi_st->clk = devm_clk_get(&pdev->dev, "ssc"); if (IS_ERR(spi_st->clk)) { dev_err(&pdev->dev, "Unable to request clock\n"); return PTR_ERR(spi_st->clk); } ret = spi_st_clk_enable(spi_st); if (ret) return ret; init_completion(&spi_st->done); /* Get resources */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); spi_st->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(spi_st->base)) { ret = PTR_ERR(spi_st->base); goto clk_disable; } /* Disable I2C and Reset SSC */ writel_relaxed(0x0, spi_st->base + SSC_I2C); var = readw_relaxed(spi_st->base + SSC_CTL); var |= SSC_CTL_SR; writel_relaxed(var, spi_st->base + SSC_CTL); udelay(1); var = readl_relaxed(spi_st->base + SSC_CTL); var &= ~SSC_CTL_SR; writel_relaxed(var, spi_st->base + SSC_CTL); /* Set SSC into slave mode before reconfiguring PIO pins */ var = readl_relaxed(spi_st->base + SSC_CTL); var &= ~SSC_CTL_MS; writel_relaxed(var, spi_st->base + SSC_CTL); irq = irq_of_parse_and_map(np, 0); if (!irq) { dev_err(&pdev->dev, "IRQ missing or invalid\n"); ret = -EINVAL; goto clk_disable; } ret = devm_request_irq(&pdev->dev, irq, spi_st_irq, 0, pdev->name, spi_st); if (ret) { dev_err(&pdev->dev, "Failed to request irq %d\n", irq); goto clk_disable; } /* by default the device is on */ pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); platform_set_drvdata(pdev, master); ret = devm_spi_register_master(&pdev->dev, master); if (ret) { dev_err(&pdev->dev, "Failed to register master\n"); goto clk_disable; } return 0; clk_disable: spi_st_clk_disable(spi_st); return ret; } static int spi_st_remove(struct platform_device *pdev) { struct spi_master *master = platform_get_drvdata(pdev); struct spi_st *spi_st = spi_master_get_devdata(master); spi_st_clk_disable(spi_st); pinctrl_pm_select_sleep_state(&pdev->dev); return 0; } #ifdef CONFIG_PM static int spi_st_runtime_suspend(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct spi_st *spi_st = spi_master_get_devdata(master); writel_relaxed(0, spi_st->base + SSC_IEN); pinctrl_pm_select_sleep_state(dev); spi_st_clk_disable(spi_st); return 0; } static int spi_st_runtime_resume(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); struct spi_st *spi_st = spi_master_get_devdata(master); int ret; ret = spi_st_clk_enable(spi_st); pinctrl_pm_select_default_state(dev); return ret; } #endif #ifdef CONFIG_PM_SLEEP static int spi_st_suspend(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); int ret; ret = spi_master_suspend(master); if (ret) return ret; return pm_runtime_force_suspend(dev); } static int spi_st_resume(struct device *dev) { struct spi_master *master = dev_get_drvdata(dev); int ret; ret = spi_master_resume(master); if (ret) return ret; return pm_runtime_force_resume(dev); } #endif static const struct dev_pm_ops spi_st_pm = { SET_SYSTEM_SLEEP_PM_OPS(spi_st_suspend, spi_st_resume) SET_RUNTIME_PM_OPS(spi_st_runtime_suspend, spi_st_runtime_resume, NULL) }; static const struct of_device_id stm_spi_match[] = { { .compatible = "st,comms-ssc4-spi", }, {}, }; MODULE_DEVICE_TABLE(of, stm_spi_match); static struct platform_driver spi_st_driver = { .driver = { .name = "spi-st", .pm = &spi_st_pm, .of_match_table = of_match_ptr(stm_spi_match), }, .probe = spi_st_probe, .remove = spi_st_remove, }; module_platform_driver(spi_st_driver); MODULE_AUTHOR("Patrice Chotard <patrice.chotard@st.com>"); MODULE_DESCRIPTION("STM SSC SPI driver"); MODULE_LICENSE("GPL v2");