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path: root/target/linux/ar71xx/files/drivers/spi/spi-rb4xx.c
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Diffstat (limited to 'target/linux/ar71xx/files/drivers/spi/spi-rb4xx.c')
-rw-r--r--target/linux/ar71xx/files/drivers/spi/spi-rb4xx.c507
1 files changed, 0 insertions, 507 deletions
diff --git a/target/linux/ar71xx/files/drivers/spi/spi-rb4xx.c b/target/linux/ar71xx/files/drivers/spi/spi-rb4xx.c
deleted file mode 100644
index 56260ff..0000000
--- a/target/linux/ar71xx/files/drivers/spi/spi-rb4xx.c
+++ /dev/null
@@ -1,507 +0,0 @@
-/*
- * SPI controller driver for the Mikrotik RB4xx boards
- *
- * Copyright (C) 2010 Gabor Juhos <juhosg@openwrt.org>
- *
- * This file was based on the patches for Linux 2.6.27.39 published by
- * MikroTik for their RouterBoard 4xx series devices.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- */
-
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/delay.h>
-#include <linux/spinlock.h>
-#include <linux/workqueue.h>
-#include <linux/platform_device.h>
-#include <linux/spi/spi.h>
-
-#include <asm/mach-ath79/ar71xx_regs.h>
-#include <asm/mach-ath79/ath79.h>
-
-#define DRV_NAME "rb4xx-spi"
-#define DRV_DESC "Mikrotik RB4xx SPI controller driver"
-#define DRV_VERSION "0.1.0"
-
-#define SPI_CTRL_FASTEST 0x40
-#define SPI_FLASH_HZ 33333334
-#define SPI_CPLD_HZ 33333334
-
-#define CPLD_CMD_READ_FAST 0x0b
-
-#undef RB4XX_SPI_DEBUG
-
-struct rb4xx_spi {
- void __iomem *base;
- struct spi_master *master;
-
- unsigned spi_ctrl_flash;
- unsigned spi_ctrl_fread;
-
- struct clk *ahb_clk;
- unsigned long ahb_freq;
-
- spinlock_t lock;
- struct list_head queue;
- int busy:1;
- int cs_wait;
-};
-
-static unsigned spi_clk_low = AR71XX_SPI_IOC_CS1;
-
-#ifdef RB4XX_SPI_DEBUG
-static inline void do_spi_delay(void)
-{
- ndelay(20000);
-}
-#else
-static inline void do_spi_delay(void) { }
-#endif
-
-static inline void do_spi_init(struct spi_device *spi)
-{
- unsigned cs = AR71XX_SPI_IOC_CS0 | AR71XX_SPI_IOC_CS1;
-
- if (!(spi->mode & SPI_CS_HIGH))
- cs ^= (spi->chip_select == 2) ? AR71XX_SPI_IOC_CS1 :
- AR71XX_SPI_IOC_CS0;
-
- spi_clk_low = cs;
-}
-
-static inline void do_spi_finish(void __iomem *base)
-{
- do_spi_delay();
- __raw_writel(AR71XX_SPI_IOC_CS0 | AR71XX_SPI_IOC_CS1,
- base + AR71XX_SPI_REG_IOC);
-}
-
-static inline void do_spi_clk(void __iomem *base, int bit)
-{
- unsigned bval = spi_clk_low | ((bit & 1) ? AR71XX_SPI_IOC_DO : 0);
-
- do_spi_delay();
- __raw_writel(bval, base + AR71XX_SPI_REG_IOC);
- do_spi_delay();
- __raw_writel(bval | AR71XX_SPI_IOC_CLK, base + AR71XX_SPI_REG_IOC);
-}
-
-static void do_spi_byte(void __iomem *base, unsigned char byte)
-{
- do_spi_clk(base, byte >> 7);
- do_spi_clk(base, byte >> 6);
- do_spi_clk(base, byte >> 5);
- do_spi_clk(base, byte >> 4);
- do_spi_clk(base, byte >> 3);
- do_spi_clk(base, byte >> 2);
- do_spi_clk(base, byte >> 1);
- do_spi_clk(base, byte);
-
- pr_debug("spi_byte sent 0x%02x got 0x%02x\n",
- (unsigned)byte,
- (unsigned char)__raw_readl(base + AR71XX_SPI_REG_RDS));
-}
-
-static inline void do_spi_clk_fast(void __iomem *base, unsigned bit1,
- unsigned bit2)
-{
- unsigned bval = (spi_clk_low |
- ((bit1 & 1) ? AR71XX_SPI_IOC_DO : 0) |
- ((bit2 & 1) ? AR71XX_SPI_IOC_CS2 : 0));
- do_spi_delay();
- __raw_writel(bval, base + AR71XX_SPI_REG_IOC);
- do_spi_delay();
- __raw_writel(bval | AR71XX_SPI_IOC_CLK, base + AR71XX_SPI_REG_IOC);
-}
-
-static void do_spi_byte_fast(void __iomem *base, unsigned char byte)
-{
- do_spi_clk_fast(base, byte >> 7, byte >> 6);
- do_spi_clk_fast(base, byte >> 5, byte >> 4);
- do_spi_clk_fast(base, byte >> 3, byte >> 2);
- do_spi_clk_fast(base, byte >> 1, byte >> 0);
-
- pr_debug("spi_byte_fast sent 0x%02x got 0x%02x\n",
- (unsigned)byte,
- (unsigned char) __raw_readl(base + AR71XX_SPI_REG_RDS));
-}
-
-static int rb4xx_spi_txrx(void __iomem *base, struct spi_transfer *t)
-{
- const unsigned char *rxv_ptr = NULL;
- const unsigned char *tx_ptr = t->tx_buf;
- unsigned char *rx_ptr = t->rx_buf;
- unsigned i;
-
- pr_debug("spi_txrx len %u tx %u rx %u\n",
- t->len,
- (t->tx_buf ? 1 : 0),
- (t->rx_buf ? 1 : 0));
-
- if (t->verify) {
- rxv_ptr = tx_ptr;
- tx_ptr = NULL;
- }
-
- for (i = 0; i < t->len; ++i) {
- unsigned char sdata = tx_ptr ? tx_ptr[i] : 0;
-
- if (t->fast_write)
- do_spi_byte_fast(base, sdata);
- else
- do_spi_byte(base, sdata);
-
- if (rx_ptr) {
- rx_ptr[i] = __raw_readl(base + AR71XX_SPI_REG_RDS) & 0xff;
- } else if (rxv_ptr) {
- unsigned char c = __raw_readl(base + AR71XX_SPI_REG_RDS);
- if (rxv_ptr[i] != c)
- return i;
- }
- }
-
- return i;
-}
-
-static int rb4xx_spi_read_fast(struct rb4xx_spi *rbspi,
- struct spi_message *m)
-{
- struct spi_transfer *t;
- const unsigned char *tx_ptr;
- unsigned addr;
- void __iomem *base = rbspi->base;
-
- /* check for exactly two transfers */
- if (list_empty(&m->transfers) ||
- list_is_last(m->transfers.next, &m->transfers) ||
- !list_is_last(m->transfers.next->next, &m->transfers)) {
- return -1;
- }
-
- /* first transfer contains command and address */
- t = list_entry(m->transfers.next,
- struct spi_transfer, transfer_list);
-
- if (t->len != 5 || t->tx_buf == NULL)
- return -1;
-
- tx_ptr = t->tx_buf;
- if (tx_ptr[0] != CPLD_CMD_READ_FAST)
- return -1;
-
- addr = tx_ptr[1];
- addr = tx_ptr[2] | (addr << 8);
- addr = tx_ptr[3] | (addr << 8);
- addr += (unsigned) base;
-
- m->actual_length += t->len;
-
- /* second transfer contains data itself */
- t = list_entry(m->transfers.next->next,
- struct spi_transfer, transfer_list);
-
- if (t->tx_buf && !t->verify)
- return -1;
-
- __raw_writel(AR71XX_SPI_FS_GPIO, base + AR71XX_SPI_REG_FS);
- __raw_writel(rbspi->spi_ctrl_fread, base + AR71XX_SPI_REG_CTRL);
- __raw_writel(0, base + AR71XX_SPI_REG_FS);
-
- if (t->rx_buf) {
- memcpy(t->rx_buf, (const void *)addr, t->len);
- } else if (t->tx_buf) {
- unsigned char buf[t->len];
- memcpy(buf, (const void *)addr, t->len);
- if (memcmp(t->tx_buf, buf, t->len) != 0)
- m->status = -EMSGSIZE;
- }
- m->actual_length += t->len;
-
- if (rbspi->spi_ctrl_flash != rbspi->spi_ctrl_fread) {
- __raw_writel(AR71XX_SPI_FS_GPIO, base + AR71XX_SPI_REG_FS);
- __raw_writel(rbspi->spi_ctrl_flash, base + AR71XX_SPI_REG_CTRL);
- __raw_writel(0, base + AR71XX_SPI_REG_FS);
- }
-
- return 0;
-}
-
-static int rb4xx_spi_msg(struct rb4xx_spi *rbspi, struct spi_message *m)
-{
- struct spi_transfer *t = NULL;
- void __iomem *base = rbspi->base;
-
- m->status = 0;
- if (list_empty(&m->transfers))
- return -1;
-
- if (m->fast_read)
- if (rb4xx_spi_read_fast(rbspi, m) == 0)
- return -1;
-
- __raw_writel(AR71XX_SPI_FS_GPIO, base + AR71XX_SPI_REG_FS);
- __raw_writel(SPI_CTRL_FASTEST, base + AR71XX_SPI_REG_CTRL);
- do_spi_init(m->spi);
-
- list_for_each_entry(t, &m->transfers, transfer_list) {
- int len;
-
- len = rb4xx_spi_txrx(base, t);
- if (len != t->len) {
- m->status = -EMSGSIZE;
- break;
- }
- m->actual_length += len;
-
- if (t->cs_change) {
- if (list_is_last(&t->transfer_list, &m->transfers)) {
- /* wait for continuation */
- return m->spi->chip_select;
- }
- do_spi_finish(base);
- ndelay(100);
- }
- }
-
- do_spi_finish(base);
- __raw_writel(rbspi->spi_ctrl_flash, base + AR71XX_SPI_REG_CTRL);
- __raw_writel(0, base + AR71XX_SPI_REG_FS);
- return -1;
-}
-
-static void rb4xx_spi_process_queue_locked(struct rb4xx_spi *rbspi,
- unsigned long *flags)
-{
- int cs = rbspi->cs_wait;
-
- rbspi->busy = 1;
- while (!list_empty(&rbspi->queue)) {
- struct spi_message *m;
-
- list_for_each_entry(m, &rbspi->queue, queue)
- if (cs < 0 || cs == m->spi->chip_select)
- break;
-
- if (&m->queue == &rbspi->queue)
- break;
-
- list_del_init(&m->queue);
- spin_unlock_irqrestore(&rbspi->lock, *flags);
-
- cs = rb4xx_spi_msg(rbspi, m);
- m->complete(m->context);
-
- spin_lock_irqsave(&rbspi->lock, *flags);
- }
-
- rbspi->cs_wait = cs;
- rbspi->busy = 0;
-
- if (cs >= 0) {
- /* TODO: add timer to unlock cs after 1s inactivity */
- }
-}
-
-static int rb4xx_spi_transfer(struct spi_device *spi,
- struct spi_message *m)
-{
- struct rb4xx_spi *rbspi = spi_master_get_devdata(spi->master);
- unsigned long flags;
-
- m->actual_length = 0;
- m->status = -EINPROGRESS;
-
- spin_lock_irqsave(&rbspi->lock, flags);
- list_add_tail(&m->queue, &rbspi->queue);
- if (rbspi->busy ||
- (rbspi->cs_wait >= 0 && rbspi->cs_wait != m->spi->chip_select)) {
- /* job will be done later */
- spin_unlock_irqrestore(&rbspi->lock, flags);
- return 0;
- }
-
- /* process job in current context */
- rb4xx_spi_process_queue_locked(rbspi, &flags);
- spin_unlock_irqrestore(&rbspi->lock, flags);
-
- return 0;
-}
-
-static int rb4xx_spi_setup(struct spi_device *spi)
-{
- struct rb4xx_spi *rbspi = spi_master_get_devdata(spi->master);
- unsigned long flags;
-
- if (spi->mode & ~(SPI_CS_HIGH)) {
- dev_err(&spi->dev, "mode %x not supported\n",
- (unsigned) spi->mode);
- return -EINVAL;
- }
-
- if (spi->bits_per_word != 8 && spi->bits_per_word != 0) {
- dev_err(&spi->dev, "bits_per_word %u not supported\n",
- (unsigned) spi->bits_per_word);
- return -EINVAL;
- }
-
- spin_lock_irqsave(&rbspi->lock, flags);
- if (rbspi->cs_wait == spi->chip_select && !rbspi->busy) {
- rbspi->cs_wait = -1;
- rb4xx_spi_process_queue_locked(rbspi, &flags);
- }
- spin_unlock_irqrestore(&rbspi->lock, flags);
-
- return 0;
-}
-
-static unsigned get_spi_ctrl(struct rb4xx_spi *rbspi, unsigned hz_max,
- const char *name)
-{
- unsigned div;
-
- div = (rbspi->ahb_freq - 1) / (2 * hz_max);
-
- /*
- * CPU has a bug at (div == 0) - first bit read is random
- */
- if (div == 0)
- ++div;
-
- if (name) {
- unsigned ahb_khz = (rbspi->ahb_freq + 500) / 1000;
- unsigned div_real = 2 * (div + 1);
- pr_debug("rb4xx: %s SPI clock %u kHz (AHB %u kHz / %u)\n",
- name,
- ahb_khz / div_real,
- ahb_khz, div_real);
- }
-
- return SPI_CTRL_FASTEST + div;
-}
-
-static int rb4xx_spi_probe(struct platform_device *pdev)
-{
- struct spi_master *master;
- struct rb4xx_spi *rbspi;
- struct resource *r;
- int err = 0;
-
- master = spi_alloc_master(&pdev->dev, sizeof(*rbspi));
- if (master == NULL) {
- dev_err(&pdev->dev, "no memory for spi_master\n");
- err = -ENOMEM;
- goto err_out;
- }
-
- master->bus_num = 0;
- master->num_chipselect = 3;
- master->setup = rb4xx_spi_setup;
- master->transfer = rb4xx_spi_transfer;
-
- rbspi = spi_master_get_devdata(master);
-
- rbspi->ahb_clk = clk_get(&pdev->dev, "ahb");
- if (IS_ERR(rbspi->ahb_clk)) {
- err = PTR_ERR(rbspi->ahb_clk);
- goto err_put_master;
- }
-
- err = clk_enable(rbspi->ahb_clk);
- if (err)
- goto err_clk_put;
-
- rbspi->ahb_freq = clk_get_rate(rbspi->ahb_clk);
- if (!rbspi->ahb_freq) {
- err = -EINVAL;
- goto err_clk_disable;
- }
-
- platform_set_drvdata(pdev, rbspi);
-
- r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (r == NULL) {
- err = -ENOENT;
- goto err_clk_disable;
- }
-
- rbspi->base = ioremap(r->start, r->end - r->start + 1);
- if (!rbspi->base) {
- err = -ENXIO;
- goto err_clk_disable;
- }
-
- rbspi->master = master;
- rbspi->spi_ctrl_flash = get_spi_ctrl(rbspi, SPI_FLASH_HZ, "FLASH");
- rbspi->spi_ctrl_fread = get_spi_ctrl(rbspi, SPI_CPLD_HZ, "CPLD");
- rbspi->cs_wait = -1;
-
- spin_lock_init(&rbspi->lock);
- INIT_LIST_HEAD(&rbspi->queue);
-
- err = spi_register_master(master);
- if (err) {
- dev_err(&pdev->dev, "failed to register SPI master\n");
- goto err_iounmap;
- }
-
- return 0;
-
-err_iounmap:
- iounmap(rbspi->base);
-err_clk_disable:
- clk_disable(rbspi->ahb_clk);
-err_clk_put:
- clk_put(rbspi->ahb_clk);
-err_put_master:
- platform_set_drvdata(pdev, NULL);
- spi_master_put(master);
-err_out:
- return err;
-}
-
-static int rb4xx_spi_remove(struct platform_device *pdev)
-{
- struct rb4xx_spi *rbspi = platform_get_drvdata(pdev);
-
- iounmap(rbspi->base);
- clk_disable(rbspi->ahb_clk);
- clk_put(rbspi->ahb_clk);
- platform_set_drvdata(pdev, NULL);
- spi_master_put(rbspi->master);
-
- return 0;
-}
-
-static struct platform_driver rb4xx_spi_drv = {
- .probe = rb4xx_spi_probe,
- .remove = rb4xx_spi_remove,
- .driver = {
- .name = DRV_NAME,
- .owner = THIS_MODULE,
- },
-};
-
-static int __init rb4xx_spi_init(void)
-{
- return platform_driver_register(&rb4xx_spi_drv);
-}
-subsys_initcall(rb4xx_spi_init);
-
-static void __exit rb4xx_spi_exit(void)
-{
- platform_driver_unregister(&rb4xx_spi_drv);
-}
-
-module_exit(rb4xx_spi_exit);
-
-MODULE_DESCRIPTION(DRV_DESC);
-MODULE_VERSION(DRV_VERSION);
-MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
-MODULE_LICENSE("GPL v2");