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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/spi/spi-bcm63xx.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/spi/spi-bcm63xx.c')
-rw-r--r--kernel/drivers/spi/spi-bcm63xx.c480
1 files changed, 480 insertions, 0 deletions
diff --git a/kernel/drivers/spi/spi-bcm63xx.c b/kernel/drivers/spi/spi-bcm63xx.c
new file mode 100644
index 000000000..e73e2b052
--- /dev/null
+++ b/kernel/drivers/spi/spi-bcm63xx.c
@@ -0,0 +1,480 @@
+/*
+ * Broadcom BCM63xx SPI controller support
+ *
+ * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
+ * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
+ *
+ * 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 program 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/spi/spi.h>
+#include <linux/completion.h>
+#include <linux/err.h>
+#include <linux/pm_runtime.h>
+
+#include <bcm63xx_dev_spi.h>
+
+#define BCM63XX_SPI_MAX_PREPEND 15
+
+struct bcm63xx_spi {
+ struct completion done;
+
+ void __iomem *regs;
+ int irq;
+
+ /* Platform data */
+ unsigned fifo_size;
+ unsigned int msg_type_shift;
+ unsigned int msg_ctl_width;
+
+ /* data iomem */
+ u8 __iomem *tx_io;
+ const u8 __iomem *rx_io;
+
+ struct clk *clk;
+ struct platform_device *pdev;
+};
+
+static inline u8 bcm_spi_readb(struct bcm63xx_spi *bs,
+ unsigned int offset)
+{
+ return bcm_readb(bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline u16 bcm_spi_readw(struct bcm63xx_spi *bs,
+ unsigned int offset)
+{
+ return bcm_readw(bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline void bcm_spi_writeb(struct bcm63xx_spi *bs,
+ u8 value, unsigned int offset)
+{
+ bcm_writeb(value, bs->regs + bcm63xx_spireg(offset));
+}
+
+static inline void bcm_spi_writew(struct bcm63xx_spi *bs,
+ u16 value, unsigned int offset)
+{
+ bcm_writew(value, bs->regs + bcm63xx_spireg(offset));
+}
+
+static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
+ { 20000000, SPI_CLK_20MHZ },
+ { 12500000, SPI_CLK_12_50MHZ },
+ { 6250000, SPI_CLK_6_250MHZ },
+ { 3125000, SPI_CLK_3_125MHZ },
+ { 1563000, SPI_CLK_1_563MHZ },
+ { 781000, SPI_CLK_0_781MHZ },
+ { 391000, SPI_CLK_0_391MHZ }
+};
+
+static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
+ struct spi_transfer *t)
+{
+ struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+ u8 clk_cfg, reg;
+ int i;
+
+ /* Find the closest clock configuration */
+ for (i = 0; i < SPI_CLK_MASK; i++) {
+ if (t->speed_hz >= bcm63xx_spi_freq_table[i][0]) {
+ clk_cfg = bcm63xx_spi_freq_table[i][1];
+ break;
+ }
+ }
+
+ /* No matching configuration found, default to lowest */
+ if (i == SPI_CLK_MASK)
+ clk_cfg = SPI_CLK_0_391MHZ;
+
+ /* clear existing clock configuration bits of the register */
+ reg = bcm_spi_readb(bs, SPI_CLK_CFG);
+ reg &= ~SPI_CLK_MASK;
+ reg |= clk_cfg;
+
+ bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
+ dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
+ clk_cfg, t->speed_hz);
+}
+
+/* the spi->mode bits understood by this driver: */
+#define MODEBITS (SPI_CPOL | SPI_CPHA)
+
+static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
+ unsigned int num_transfers)
+{
+ struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+ u16 msg_ctl;
+ u16 cmd;
+ u8 rx_tail;
+ unsigned int i, timeout = 0, prepend_len = 0, len = 0;
+ struct spi_transfer *t = first;
+ bool do_rx = false;
+ bool do_tx = false;
+
+ /* Disable the CMD_DONE interrupt */
+ bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
+ dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
+ t->tx_buf, t->rx_buf, t->len);
+
+ if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
+ prepend_len = t->len;
+
+ /* prepare the buffer */
+ for (i = 0; i < num_transfers; i++) {
+ if (t->tx_buf) {
+ do_tx = true;
+ memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
+
+ /* don't prepend more than one tx */
+ if (t != first)
+ prepend_len = 0;
+ }
+
+ if (t->rx_buf) {
+ do_rx = true;
+ /* prepend is half-duplex write only */
+ if (t == first)
+ prepend_len = 0;
+ }
+
+ len += t->len;
+
+ t = list_entry(t->transfer_list.next, struct spi_transfer,
+ transfer_list);
+ }
+
+ reinit_completion(&bs->done);
+
+ /* Fill in the Message control register */
+ msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
+
+ if (do_rx && do_tx && prepend_len == 0)
+ msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
+ else if (do_rx)
+ msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
+ else if (do_tx)
+ msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
+
+ switch (bs->msg_ctl_width) {
+ case 8:
+ bcm_spi_writeb(bs, msg_ctl, SPI_MSG_CTL);
+ break;
+ case 16:
+ bcm_spi_writew(bs, msg_ctl, SPI_MSG_CTL);
+ break;
+ }
+
+ /* Issue the transfer */
+ cmd = SPI_CMD_START_IMMEDIATE;
+ cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+ cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
+ bcm_spi_writew(bs, cmd, SPI_CMD);
+
+ /* Enable the CMD_DONE interrupt */
+ bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
+
+ timeout = wait_for_completion_timeout(&bs->done, HZ);
+ if (!timeout)
+ return -ETIMEDOUT;
+
+ if (!do_rx)
+ return 0;
+
+ len = 0;
+ t = first;
+ /* Read out all the data */
+ for (i = 0; i < num_transfers; i++) {
+ if (t->rx_buf)
+ memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
+
+ if (t != first || prepend_len == 0)
+ len += t->len;
+
+ t = list_entry(t->transfer_list.next, struct spi_transfer,
+ transfer_list);
+ }
+
+ return 0;
+}
+
+static int bcm63xx_spi_transfer_one(struct spi_master *master,
+ struct spi_message *m)
+{
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+ struct spi_transfer *t, *first = NULL;
+ struct spi_device *spi = m->spi;
+ int status = 0;
+ unsigned int n_transfers = 0, total_len = 0;
+ bool can_use_prepend = false;
+
+ /*
+ * This SPI controller does not support keeping CS active after a
+ * transfer.
+ * Work around this by merging as many transfers we can into one big
+ * full-duplex transfers.
+ */
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ if (!first)
+ first = t;
+
+ n_transfers++;
+ total_len += t->len;
+
+ if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
+ first->len <= BCM63XX_SPI_MAX_PREPEND)
+ can_use_prepend = true;
+ else if (can_use_prepend && t->tx_buf)
+ can_use_prepend = false;
+
+ /* we can only transfer one fifo worth of data */
+ if ((can_use_prepend &&
+ total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
+ (!can_use_prepend && total_len > bs->fifo_size)) {
+ dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
+ total_len, bs->fifo_size);
+ status = -EINVAL;
+ goto exit;
+ }
+
+ /* all combined transfers have to have the same speed */
+ if (t->speed_hz != first->speed_hz) {
+ dev_err(&spi->dev, "unable to change speed between transfers\n");
+ status = -EINVAL;
+ goto exit;
+ }
+
+ /* CS will be deasserted directly after transfer */
+ if (t->delay_usecs) {
+ dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
+ status = -EINVAL;
+ goto exit;
+ }
+
+ if (t->cs_change ||
+ list_is_last(&t->transfer_list, &m->transfers)) {
+ /* configure adapter for a new transfer */
+ bcm63xx_spi_setup_transfer(spi, first);
+
+ /* send the data */
+ status = bcm63xx_txrx_bufs(spi, first, n_transfers);
+ if (status)
+ goto exit;
+
+ m->actual_length += total_len;
+
+ first = NULL;
+ n_transfers = 0;
+ total_len = 0;
+ can_use_prepend = false;
+ }
+ }
+exit:
+ m->status = status;
+ spi_finalize_current_message(master);
+
+ return 0;
+}
+
+/* This driver supports single master mode only. Hence
+ * CMD_DONE is the only interrupt we care about
+ */
+static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
+{
+ struct spi_master *master = (struct spi_master *)dev_id;
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+ u8 intr;
+
+ /* Read interupts and clear them immediately */
+ intr = bcm_spi_readb(bs, SPI_INT_STATUS);
+ bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
+ bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
+ /* A transfer completed */
+ if (intr & SPI_INTR_CMD_DONE)
+ complete(&bs->done);
+
+ return IRQ_HANDLED;
+}
+
+
+static int bcm63xx_spi_probe(struct platform_device *pdev)
+{
+ struct resource *r;
+ struct device *dev = &pdev->dev;
+ struct bcm63xx_spi_pdata *pdata = dev_get_platdata(&pdev->dev);
+ int irq;
+ struct spi_master *master;
+ struct clk *clk;
+ struct bcm63xx_spi *bs;
+ int ret;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(dev, "no irq\n");
+ return -ENXIO;
+ }
+
+ clk = devm_clk_get(dev, "spi");
+ if (IS_ERR(clk)) {
+ dev_err(dev, "no clock for device\n");
+ return PTR_ERR(clk);
+ }
+
+ master = spi_alloc_master(dev, sizeof(*bs));
+ if (!master) {
+ dev_err(dev, "out of memory\n");
+ return -ENOMEM;
+ }
+
+ bs = spi_master_get_devdata(master);
+ init_completion(&bs->done);
+
+ platform_set_drvdata(pdev, master);
+ bs->pdev = pdev;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ bs->regs = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(bs->regs)) {
+ ret = PTR_ERR(bs->regs);
+ goto out_err;
+ }
+
+ bs->irq = irq;
+ bs->clk = clk;
+ bs->fifo_size = pdata->fifo_size;
+
+ ret = devm_request_irq(&pdev->dev, irq, bcm63xx_spi_interrupt, 0,
+ pdev->name, master);
+ if (ret) {
+ dev_err(dev, "unable to request irq\n");
+ goto out_err;
+ }
+
+ master->bus_num = pdata->bus_num;
+ master->num_chipselect = pdata->num_chipselect;
+ master->transfer_one_message = bcm63xx_spi_transfer_one;
+ master->mode_bits = MODEBITS;
+ master->bits_per_word_mask = SPI_BPW_MASK(8);
+ master->auto_runtime_pm = true;
+ bs->msg_type_shift = pdata->msg_type_shift;
+ bs->msg_ctl_width = pdata->msg_ctl_width;
+ bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA));
+ bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA));
+
+ switch (bs->msg_ctl_width) {
+ case 8:
+ case 16:
+ break;
+ default:
+ dev_err(dev, "unsupported MSG_CTL width: %d\n",
+ bs->msg_ctl_width);
+ goto out_err;
+ }
+
+ /* Initialize hardware */
+ ret = clk_prepare_enable(bs->clk);
+ if (ret)
+ goto out_err;
+
+ bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
+
+ /* register and we are done */
+ ret = devm_spi_register_master(dev, master);
+ if (ret) {
+ dev_err(dev, "spi register failed\n");
+ goto out_clk_disable;
+ }
+
+ dev_info(dev, "at 0x%08x (irq %d, FIFOs size %d)\n",
+ r->start, irq, bs->fifo_size);
+
+ return 0;
+
+out_clk_disable:
+ clk_disable_unprepare(clk);
+out_err:
+ spi_master_put(master);
+ return ret;
+}
+
+static int bcm63xx_spi_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+
+ /* reset spi block */
+ bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
+ /* HW shutdown */
+ clk_disable_unprepare(bs->clk);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int bcm63xx_spi_suspend(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+
+ spi_master_suspend(master);
+
+ clk_disable_unprepare(bs->clk);
+
+ return 0;
+}
+
+static int bcm63xx_spi_resume(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+ int ret;
+
+ ret = clk_prepare_enable(bs->clk);
+ if (ret)
+ return ret;
+
+ spi_master_resume(master);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops bcm63xx_spi_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(bcm63xx_spi_suspend, bcm63xx_spi_resume)
+};
+
+static struct platform_driver bcm63xx_spi_driver = {
+ .driver = {
+ .name = "bcm63xx-spi",
+ .pm = &bcm63xx_spi_pm_ops,
+ },
+ .probe = bcm63xx_spi_probe,
+ .remove = bcm63xx_spi_remove,
+};
+
+module_platform_driver(bcm63xx_spi_driver);
+
+MODULE_ALIAS("platform:bcm63xx_spi");
+MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
+MODULE_AUTHOR("Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>");
+MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
+MODULE_LICENSE("GPL");