--- /dev/null
+/*
+ * omap_uwire.c -- MicroWire interface driver for OMAP
+ *
+ * Copyright 2003 MontaVista Software Inc. <source@mvista.com>
+ *
+ * Ported to 2.6 OMAP uwire interface.
+ * Copyright (C) 2004 Texas Instruments.
+ *
+ * Generalization patches by Juha Yrjölä <juha.yrjola@nokia.com>
+ *
+ * Copyright (C) 2005 David Brownell (ported to 2.6 SPI interface)
+ *
+ * This program 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 SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/hardware.h>
+#include <asm/io.h>
+#include <asm/mach-types.h>
+
+#include <asm/arch/mux.h>
+#include <asm/arch/omap730.h> /* OMAP730_IO_CONF registers */
+
+
+/* FIXME address is now a platform device resource,
+ * and irqs should show there too...
+ */
+#define UWIRE_BASE_PHYS 0xFFFB3000
+#define UWIRE_BASE ((void *__iomem)IO_ADDRESS(UWIRE_BASE_PHYS))
+
+/* uWire Registers: */
+#define UWIRE_IO_SIZE 0x20
+#define UWIRE_TDR 0x00
+#define UWIRE_RDR 0x00
+#define UWIRE_CSR 0x01
+#define UWIRE_SR1 0x02
+#define UWIRE_SR2 0x03
+#define UWIRE_SR3 0x04
+#define UWIRE_SR4 0x05
+#define UWIRE_SR5 0x06
+
+/* CSR bits */
+#define RDRB (1 << 15)
+#define CSRB (1 << 14)
+#define START (1 << 13)
+#define CS_CMD (1 << 12)
+
+/* SR1 or SR2 bits */
+#define UWIRE_READ_FALLING_EDGE 0x0000
+#define UWIRE_READ_RISING_EDGE 0x0001
+#define UWIRE_WRITE_FALLING_EDGE 0x0000
+#define UWIRE_WRITE_RISING_EDGE 0x0002
+#define UWIRE_CS_ACTIVE_LOW 0x0000
+#define UWIRE_CS_ACTIVE_HIGH 0x0004
+#define UWIRE_FREQ_DIV_2 0x0000
+#define UWIRE_FREQ_DIV_4 0x0008
+#define UWIRE_FREQ_DIV_8 0x0010
+#define UWIRE_CHK_READY 0x0020
+#define UWIRE_CLK_INVERTED 0x0040
+
+
+struct uwire_spi {
+ struct spi_bitbang bitbang;
+ struct clk *ck;
+};
+
+/* REVISIT compile time constant for idx_shift? */
+static unsigned int uwire_idx_shift;
+
+static inline void uwire_write_reg(int idx, u16 val)
+{
+ __raw_writew(val, UWIRE_BASE + (idx << uwire_idx_shift));
+}
+
+static inline u16 uwire_read_reg(int idx)
+{
+ return __raw_readw(UWIRE_BASE + (idx << uwire_idx_shift));
+}
+
+static inline void omap_uwire_configure_mode(u8 cs, unsigned long flags)
+{
+ u16 w, val = 0;
+ int shift, reg;
+
+ if (flags & UWIRE_CLK_INVERTED)
+ val ^= 0x03;
+ val = flags & 0x3f;
+ if (cs & 1)
+ shift = 6;
+ else
+ shift = 0;
+ if (cs <= 1)
+ reg = UWIRE_SR1;
+ else
+ reg = UWIRE_SR2;
+
+ w = uwire_read_reg(reg);
+ w &= ~(0x3f << shift);
+ w |= val << shift;
+ uwire_write_reg(reg, w);
+}
+
+static int wait_uwire_csr_flag(u16 mask, u16 val, int might_not_catch)
+{
+ u16 w;
+ int c = 0;
+ unsigned long max_jiffies = jiffies + HZ;
+
+ for (;;) {
+ w = uwire_read_reg(UWIRE_CSR);
+ if ((w & mask) == val)
+ break;
+ if (time_after(jiffies, max_jiffies)) {
+ printk(KERN_ERR "%s: timeout. reg=%#06x "
+ "mask=%#06x val=%#06x\n",
+ __FUNCTION__, w, mask, val);
+ return -1;
+ }
+ c++;
+ if (might_not_catch && c > 64)
+ break;
+ }
+ return 0;
+}
+
+static void uwire_chipselect(struct spi_device *spi, int value)
+{
+ u16 w;
+
+ BUG_ON(wait_uwire_csr_flag(CSRB, 0, 0));
+
+ /* activate/deactivate specfied chipselect */
+ if (value == BITBANG_CS_ACTIVE) {
+ /* invert clock? */
+ if (spi->mode & SPI_CPOL)
+ uwire_write_reg(UWIRE_SR4, 1);
+ else
+ uwire_write_reg(UWIRE_SR4, 0);
+
+ w = spi->chip_select << 10;
+ w |= CS_CMD;
+ } else
+ w = 0;
+ uwire_write_reg(UWIRE_CSR, w);
+}
+
+static int uwire_txrx(struct spi_device *spi, struct spi_transfer *t)
+{
+ unsigned len = t->len;
+ unsigned bits = spi->bits_per_word;
+ unsigned bytes;
+ u16 val, w;
+ int status = 0;;
+
+ if (!t->tx_buf && !t->rx_buf)
+ return 0;
+
+ /* Microwire doesn't read and write concurrently */
+ if (t->tx_buf && t->rx_buf)
+ return -EPERM;
+
+ w = spi->chip_select << 10;
+ w |= CS_CMD;
+
+ if (t->tx_buf) {
+ const u8 *buf = t->tx_buf;
+
+ /* NOTE: DMA could be used for TX transfers */
+
+ /* write one or two bytes at a time */
+ while (len >= 1) {
+ /* tx is msb-aligned */
+ val = *buf++;
+ if (len > 1 && (!bits || bits > 8)) {
+ if (!bits)
+ bits = 16;
+ bytes = 2;
+ val |= *buf++ << 8;
+ } else {
+ if (!bits || bits > 8)
+ bits = 8;
+ bytes = 1;
+ }
+ val <<= 16 - bits;
+
+#ifdef VERBOSE
+ pr_debug("%s: write-%d =%04x\n",
+ spi->dev.bus_id, bits, val);
+#endif
+ uwire_write_reg(UWIRE_TDR, val);
+
+ /* start write */
+ val = START | w | (bits << 5);
+ if (wait_uwire_csr_flag(CSRB, 0, 0))
+ goto eio;
+
+ uwire_write_reg(UWIRE_CSR, val);
+ len -= bytes;
+
+ /* Wait till write actually starts.
+ * This is needed with MPU clock 60+ MHz.
+ * REVISIT: we may not have time to catch it...
+ */
+ if (wait_uwire_csr_flag(CSRB, CSRB, 1))
+ goto eio;
+
+ status += bytes;
+ }
+
+ /* REVISIT: save this for later to get more i/o overlap */
+ if (wait_uwire_csr_flag(CSRB, 0, 0))
+ goto eio;
+
+ } else if (t->rx_buf) {
+ u8 *buf = t->rx_buf;
+
+ /* read one or two bytes at a time */
+ while (len) {
+ if (len > 1 && (!bits || bits > 8)) {
+ if (!bits)
+ bits = 16;
+ bytes = 2;
+ } else {
+ if (!bits || bits > 8)
+ bits = 8;
+ bytes = 1;
+ }
+
+ /* start read */
+ val = START | w | (bits << 0);
+ uwire_write_reg(UWIRE_CSR, val);
+ len -= bytes;
+
+ /* Wait till read actually starts */
+ (void) wait_uwire_csr_flag(CSRB, CSRB, 1);
+
+ if (wait_uwire_csr_flag(RDRB | CSRB,
+ RDRB, 0))
+ goto eio;
+
+ /* rx is lsb-aligned */
+ val = uwire_read_reg(UWIRE_RDR);
+ val &= (1 << bits) - 1;
+ *buf++ = (u8) val;
+ if (bytes == 2)
+ *buf++ = val >> 8;
+ status += len;
+#ifdef VERBOSE
+ pr_debug("%s: read-%d =%04x\n",
+ spi->dev.bus_id, bits, val);
+#endif
+
+ }
+ }
+ return status;
+eio:
+ return -EIO;
+}
+
+static int uwire_setup(struct spi_device *spi)
+{
+ struct uwire_spi *uwire;
+ unsigned flags = 0;
+ unsigned long rate;
+ u16 div1;
+ int status;
+
+ uwire = spi_master_get_devdata(spi->master);
+
+ if (spi->chip_select > 3) {
+ pr_debug("%s: cs%d?\n", spi->dev.bus_id, spi->chip_select);
+ status = -ENODEV;
+ goto done;
+ }
+
+ if (spi->bits_per_word > 16) {
+ pr_debug("%s: wordsize %d?\n", spi->dev.bus_id,
+ spi->bits_per_word);
+ status = -ENODEV;
+ goto done;
+ }
+
+ /* mode 0..3, clock inverted separately;
+ * standard nCS signaling;
+ * don't treat DI=high as "not ready"
+ */
+ if (spi->mode & SPI_CS_HIGH)
+ flags |= UWIRE_CS_ACTIVE_HIGH;
+
+ if (spi->mode & SPI_CPOL)
+ flags |= UWIRE_CLK_INVERTED;
+
+ switch (spi->mode & (SPI_CPOL | SPI_CPHA)) {
+ case SPI_MODE_0:
+ case SPI_MODE_3:
+ flags |= UWIRE_WRITE_FALLING_EDGE | UWIRE_READ_FALLING_EDGE;
+ break;
+ case SPI_MODE_1:
+ case SPI_MODE_2:
+ flags |= UWIRE_WRITE_FALLING_EDGE | UWIRE_READ_RISING_EDGE;
+ break;
+ }
+
+ /* assume it's already enabled */
+ rate = clk_get_rate(uwire->ck);
+
+ /* F_INT = mpu_per_clk / DIV1 */
+ div1 = (uwire_read_reg(UWIRE_SR3) >> 1) & 0x3;
+ switch (div1) {
+ case 0: rate /= 2; break;
+ case 1: rate /= 4; break;
+ case 2: rate /= 7; break;
+ case 3: rate /= 10; break;
+ }
+
+ /* SCLK = F_INT / DIV2 */
+ rate >>= 1;
+ if (rate <= spi->max_speed_hz)
+ flags |= UWIRE_FREQ_DIV_2;
+ else {
+ rate >>= 1;
+ if (rate <= spi->max_speed_hz)
+ flags |= UWIRE_FREQ_DIV_4;
+ else {
+ rate >>= 1;
+ if (rate <= spi->max_speed_hz)
+ flags |= UWIRE_FREQ_DIV_8;
+ else {
+ /* REVISIT: we could change DIV2 */
+ pr_debug("%s: lowest clock %ld, need %d, "
+ "div1 %d\n",
+ spi->dev.bus_id, rate,
+ spi->max_speed_hz, div1);
+ status = -EDOM;
+ goto done;
+ }
+ }
+ }
+ omap_uwire_configure_mode(spi->chip_select, flags);
+ pr_debug("%s: uwire flags %02x, armper %lu KHz, SCK %lu KHz\n",
+ __FUNCTION__, flags,
+ clk_get_rate(uwire->ck) / 1000,
+ rate / 1000);
+ status = 0;
+done:
+ return status;
+}
+
+static void uwire_off(struct uwire_spi *uwire)
+{
+ uwire_write_reg(UWIRE_SR3, 0);
+ clk_disable(uwire->ck);
+ clk_put(uwire->ck);
+ spi_master_put(uwire->bitbang.master);
+}
+
+static int uwire_probe(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct uwire_spi *uwire;
+ int status;
+
+ master = spi_alloc_master(&pdev->dev, sizeof *uwire);
+ if (!master)
+ return -ENODEV;
+
+ uwire = spi_master_get_devdata(master);
+ dev_set_drvdata(&pdev->dev, uwire);
+
+ uwire->ck = clk_get(&pdev->dev, "armper_ck");
+ if (!uwire->ck || IS_ERR(uwire->ck)) {
+ dev_dbg(&pdev->dev, "no mpu_per_clk ?\n");
+ spi_master_put(master);
+ return -ENODEV;
+ }
+ clk_enable(uwire->ck);
+
+ if (cpu_is_omap730())
+ uwire_idx_shift = 1;
+ else
+ uwire_idx_shift = 2;
+
+ uwire_write_reg(UWIRE_SR3, 1);
+
+ master->bus_num = 2; /* "official" */
+ master->num_chipselect = 4;
+ master->setup = uwire_setup;
+
+ uwire->bitbang.master = master;
+ uwire->bitbang.chipselect = uwire_chipselect;
+ uwire->bitbang.txrx_bufs = uwire_txrx;
+
+ status = spi_bitbang_start(&uwire->bitbang);
+ if (status < 0)
+ uwire_off(uwire);
+ return status;
+}
+
+static int uwire_remove(struct platform_device *pdev)
+{
+ struct uwire_spi *uwire = dev_get_drvdata(&pdev->dev);
+ int status;
+
+ // FIXME remove all child devices, somewhere ...
+
+ status = spi_bitbang_stop(&uwire->bitbang);
+ uwire_off(uwire);
+ return status;
+}
+
+static struct platform_driver uwire_driver = {
+ .driver = {
+ .name = "omap_uwire",
+ .bus = &platform_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = uwire_probe,
+ .remove = uwire_remove,
+ // suspend ... unuse ck
+ // resume ... use ck
+};
+
+static int __init omap_uwire_init(void)
+{
+ /* FIXME move these into the relevant board init code. also, include
+ * H3 support; it uses tsc2101 like H2 (on a different chipselect).
+ */
+
+ if (machine_is_omap_h2()) {
+ /* defaults: W21 SDO, U18 SDI, V19 SCL */
+ omap_cfg_reg(N14_1610_UWIRE_CS0);
+ omap_cfg_reg(N15_1610_UWIRE_CS1);
+ }
+ if (machine_is_omap_perseus2()) {
+ /* configure pins: MPU_UW_nSCS1, MPU_UW_SDO, MPU_UW_SCLK */
+ int val = omap_readl(OMAP730_IO_CONF_9) & ~0x00EEE000;
+ omap_writel(val | 0x00AAA000, OMAP730_IO_CONF_9);
+ }
+
+ return platform_driver_register(&uwire_driver);
+}
+
+static void __exit omap_uwire_exit(void)
+{
+ platform_driver_unregister(&uwire_driver);
+}
+
+subsys_initcall(omap_uwire_init);
+module_exit(omap_uwire_exit);
+
+MODULE_LICENSE("GPL");
projects / linux-2.6-omap-h63xx.git / commitdiff