diff options
Diffstat (limited to 'target/linux/ar71xx/files/drivers/spi/spi-rb4xx.c')
-rw-r--r-- | target/linux/ar71xx/files/drivers/spi/spi-rb4xx.c | 507 |
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"); |