From: Cyril Chemparathy <cyril-l0cyMroinI0@public.gmane.org>
To: davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org,
spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org,
lrg-kDsPt+C1G03kYMGBc/C6ZA@public.gmane.org,
dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Cc: Cyril Chemparathy <cyril-l0cyMroinI0@public.gmane.org>
Subject: [PATCH 04/12] spi: add ti-ssp spi master driver
Date: Thu, 14 Oct 2010 14:38:47 -0400 [thread overview]
Message-ID: <1287081535-2864-5-git-send-email-cyril@ti.com> (raw)
In-Reply-To: <1287081535-2864-1-git-send-email-cyril-l0cyMroinI0@public.gmane.org>
This patch adds an SPI master implementation that operates on top of an
underlying TI-SSP port.
Signed-off-by: Cyril Chemparathy <cyril-l0cyMroinI0@public.gmane.org>
---
arch/arm/mach-davinci/include/mach/ti_ssp.h | 6 +
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 1 +
drivers/spi/spi_ti_ssp.c | 408 +++++++++++++++++++++++++++
4 files changed, 421 insertions(+), 0 deletions(-)
create mode 100644 drivers/spi/spi_ti_ssp.c
diff --git a/arch/arm/mach-davinci/include/mach/ti_ssp.h b/arch/arm/mach-davinci/include/mach/ti_ssp.h
index 8365101..532b0a3 100644
--- a/arch/arm/mach-davinci/include/mach/ti_ssp.h
+++ b/arch/arm/mach-davinci/include/mach/ti_ssp.h
@@ -32,6 +32,12 @@ struct ti_ssp_port_data {
unsigned long config;
};
+struct ti_ssp_spi_data {
+ struct ti_ssp_port_data port_data;
+ int num_cs;
+ void (*select)(int cs);
+};
+
struct ti_ssp_port;
/*
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 91c2f4f..c1937e4 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -298,6 +298,12 @@ config SPI_STMP3XXX
help
SPI driver for Freescale STMP37xx/378x SoC SSP interface
+config SPI_TI_SSP
+ tristate "TI SSP Controller SPI Driver"
+ depends on SPI_MASTER && TI_SSP
+ help
+ SPI master implementation using a TI sequencer serial port.
+
config SPI_TXX9
tristate "Toshiba TXx9 SPI controller"
depends on GENERIC_GPIO && CPU_TX49XX
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index e9cbd18..953aba7 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_SPI_S3C24XX_GPIO) += spi_s3c24xx_gpio.o
obj-$(CONFIG_SPI_S3C24XX) += spi_s3c24xx_hw.o
obj-$(CONFIG_SPI_S3C64XX) += spi_s3c64xx.o
obj-$(CONFIG_SPI_TXX9) += spi_txx9.o
+obj-$(CONFIG_SPI_TI_SSP) += spi_ti_ssp.o
obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o
obj-$(CONFIG_SPI_XILINX_OF) += xilinx_spi_of.o
obj-$(CONFIG_SPI_XILINX_PLTFM) += xilinx_spi_pltfm.o
diff --git a/drivers/spi/spi_ti_ssp.c b/drivers/spi/spi_ti_ssp.c
new file mode 100644
index 0000000..132684c
--- /dev/null
+++ b/drivers/spi/spi_ti_ssp.c
@@ -0,0 +1,408 @@
+/*
+ * Sequencer Serial Port (SSP) based SPI master driver
+ *
+ * Copyright (C) 2010 Texas Instruments Inc
+ *
+ * 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.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+
+#include <mach/ti_ssp.h>
+
+#define MODE_BITS (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH)
+
+struct ti_ssp_spi {
+ struct spi_master *master;
+ const struct ti_ssp_spi_data *pdata;
+ struct device *dev;
+ spinlock_t lock;
+ struct list_head msg_queue;
+ struct completion complete;
+ int shutdown:1;
+ struct workqueue_struct *workqueue;
+ struct work_struct work;
+ u8 mode, bpw;
+ int cs_active;
+ struct ti_ssp_port *ssp;
+ u32 pc_en, pc_dis, pc_wr, pc_rd;
+};
+
+static u32 do_read_data(struct ti_ssp_spi *hw)
+{
+ u32 ret;
+
+ ti_ssp_run(hw->ssp, hw->pc_rd, 0, &ret);
+ return ret;
+}
+
+static void do_write_data(struct ti_ssp_spi *hw, u32 data)
+{
+ ti_ssp_run(hw->ssp, hw->pc_wr, data << (32 - hw->bpw), NULL);
+}
+
+static int do_transfer(struct ti_ssp_spi *hw, struct spi_message *msg,
+ struct spi_transfer *t)
+{
+ int count;
+
+ if (hw->bpw <= 8) {
+ u8 *rx = t->rx_buf;
+ const u8 *tx = t->tx_buf;
+
+ for (count = 0; count < t->len; count += 1) {
+ if (t->tx_buf)
+ do_write_data(hw, *tx++);
+ if (t->rx_buf)
+ *rx++ = do_read_data(hw);
+ }
+ } else if (hw->bpw <= 16) {
+ u16 *rx = t->rx_buf;
+ const u16 *tx = t->tx_buf;
+
+ for (count = 0; count < t->len; count += 2) {
+ if (t->tx_buf)
+ do_write_data(hw, *tx++);
+ if (t->rx_buf)
+ *rx++ = do_read_data(hw);
+ }
+ } else {
+ u32 *rx = t->rx_buf;
+ const u32 *tx = t->tx_buf;
+
+ for (count = 0; count < t->len; count += 4) {
+ if (t->tx_buf)
+ do_write_data(hw, *tx++);
+ if (t->rx_buf)
+ *rx++ = do_read_data(hw);
+ }
+ }
+
+ msg->actual_length += count; /* bytes transferred */
+
+ dev_dbg(&msg->spi->dev, "xfer %s%s, %d bytes, %d bpw, count %d%s\n",
+ t->tx_buf ? "tx" : "", t->rx_buf ? "rx" : "", t->len,
+ hw->bpw, count, (count < t->len) ? " (under)": "");
+
+ return (count < t->len) ? -EIO : 0; /* left over data */
+}
+
+static void chip_select(struct ti_ssp_spi *hw, int cs_active)
+{
+ cs_active = !!cs_active;
+ if (cs_active == hw->cs_active)
+ return;
+ ti_ssp_run(hw->ssp, cs_active ? hw->pc_en : hw->pc_dis, 0, NULL);
+ hw->cs_active = cs_active;
+}
+
+#define __SHIFT_OUT(bits) (SSP_OPCODE_SHIFT | SSP_OUT_MODE | \
+ cs_en | clk | SSP_COUNT((bits) * 2 - 1))
+#define __SHIFT_IN(bits) (SSP_OPCODE_SHIFT | SSP_IN_MODE | \
+ cs_en | clk | SSP_COUNT((bits) * 2 - 1))
+
+static int setup_xfer(struct ti_ssp_spi *hw, u8 bpw, u8 mode)
+{
+ int error, idx = 0;
+ u32 seqram[16];
+ u32 cs_en, cs_dis, clk;
+ u32 topbits, botbits;
+
+ mode &= MODE_BITS;
+ if (mode == hw->mode && bpw == hw->bpw)
+ return 0;
+
+ cs_en = (mode & SPI_CS_HIGH) ? SSP_CS_HIGH : SSP_CS_LOW;
+ cs_dis = (mode & SPI_CS_HIGH) ? SSP_CS_LOW : SSP_CS_HIGH;
+ clk = (mode & SPI_CPOL) ? SSP_CLK_HIGH : SSP_CLK_LOW;
+
+ /* Construct instructions */
+
+ /* Disable Chip Select */
+ hw->pc_dis = idx;
+ seqram[idx++] = SSP_OPCODE_DIRECT | SSP_OUT_MODE | cs_dis | clk;
+ seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_dis | clk;
+
+ /* Enable Chip Select */
+ hw->pc_en = idx;
+ seqram[idx++] = SSP_OPCODE_DIRECT | SSP_OUT_MODE | cs_en | clk;
+ seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk;
+
+ /* Reads and writes need to be split for bpw > 16 */
+ topbits = (bpw > 16) ? 16 : bpw;
+ botbits = bpw - topbits;
+
+ /* Write */
+ hw->pc_wr = idx;
+ seqram[idx++] = __SHIFT_OUT(topbits) | SSP_ADDR_REG;
+ if (botbits)
+ seqram[idx++] = __SHIFT_OUT(botbits) | SSP_DATA_REG;
+ seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk;
+
+ /* Read */
+ hw->pc_rd = idx;
+ if (botbits)
+ seqram[idx++] = __SHIFT_IN(botbits) | SSP_ADDR_REG;
+ seqram[idx++] = __SHIFT_IN(topbits) | SSP_DATA_REG;
+ seqram[idx++] = SSP_OPCODE_STOP | SSP_OUT_MODE | cs_en | clk;
+
+ error = ti_ssp_load(hw->ssp, 0, seqram, idx);
+ if (error < 0)
+ return error;
+
+ error = ti_ssp_set_mode(hw->ssp, ((mode & SPI_CPHA) ?
+ 0 : SSP_EARLY_DIN));
+ if (error < 0)
+ return error;
+
+ hw->bpw = bpw;
+ hw->mode = mode;
+
+ return error;
+}
+
+static void ti_ssp_spi_work(struct work_struct *work)
+{
+ struct ti_ssp_spi *hw = container_of(work, struct ti_ssp_spi, work);
+
+ spin_lock_irq(&hw->lock);
+
+ while (!list_empty(&hw->msg_queue)) {
+ struct spi_message *m;
+ struct spi_device *spi;
+ struct spi_transfer *t = NULL;
+ int status = 0;
+
+ m = container_of(hw->msg_queue.next, struct spi_message,
+ queue);
+
+ list_del_init(&m->queue);
+
+ spi = m->spi;
+
+ if (hw->pdata->select)
+ hw->pdata->select(spi->chip_select);
+
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ int bpw = spi->bits_per_word;
+ int xfer_status;
+
+ if (t->bits_per_word)
+ bpw = t->bits_per_word;
+
+ if (setup_xfer(hw, bpw, spi->mode) < 0)
+ break;
+
+ chip_select(hw, 1);
+
+ spin_unlock_irq(&hw->lock);
+
+ xfer_status = do_transfer(hw, m, t);
+ if (xfer_status < 0)
+ status = xfer_status;
+
+ if (t->delay_usecs)
+ udelay(t->delay_usecs);
+
+ spin_lock_irq(&hw->lock);
+
+ if (t->cs_change)
+ chip_select(hw, 0);
+ }
+
+ chip_select(hw, 0);
+ m->status = status;
+ m->complete(m->context);
+ }
+
+ if (hw->shutdown)
+ complete(&hw->complete);
+
+ spin_unlock_irq(&hw->lock);
+}
+
+static int ti_ssp_spi_setup(struct spi_device *spi)
+{
+ if (spi->bits_per_word > 32)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int ti_ssp_spi_transfer(struct spi_device *spi, struct spi_message *m)
+{
+ struct ti_ssp_spi *hw;
+ struct spi_transfer *t;
+ unsigned long flags;
+ int error = 0;
+
+ m->actual_length = 0;
+ m->status = -EINPROGRESS;
+
+ hw = spi_master_get_devdata(spi->master);
+
+ if (list_empty(&m->transfers) || !m->complete)
+ return -EINVAL;
+
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ if (t->len && !(t->rx_buf || t->tx_buf)) {
+ dev_err(&spi->dev, "invalid xfer, no buffer\n");
+ return -EINVAL;
+ }
+
+ if (t->len && t->rx_buf && t->tx_buf) {
+ dev_err(&spi->dev, "invalid xfer, full duplex\n");
+ return -EINVAL;
+ }
+
+ if (t->bits_per_word > 32) {
+ dev_err(&spi->dev, "invalid xfer width %d\n",
+ t->bits_per_word);
+ return -EINVAL;
+ }
+ }
+
+ spin_lock_irqsave(&hw->lock, flags);
+ if (hw->shutdown) {
+ error = -ESHUTDOWN;
+ goto error_unlock;
+ }
+ list_add_tail(&m->queue, &hw->msg_queue);
+ queue_work(hw->workqueue, &hw->work);
+error_unlock:
+ spin_unlock_irqrestore(&hw->lock, flags);
+ return error;
+}
+
+static int __devinit ti_ssp_spi_probe(struct platform_device *pdev)
+{
+ const struct ti_ssp_spi_data *pdata;
+ struct ti_ssp_spi *hw;
+ struct spi_master *master;
+ struct device *dev = &pdev->dev;
+ int error = 0;
+
+ pdata = dev->platform_data;
+ if (!pdata) {
+ dev_err(dev, "platform data not found\n");
+ return -EINVAL;
+ }
+
+ master = spi_alloc_master(dev, sizeof(struct ti_ssp_spi));
+ if (!master) {
+ dev_err(dev, "cannot allocate SPI master\n");
+ return -ENOMEM;
+ }
+
+ hw = spi_master_get_devdata(master);
+ platform_set_drvdata(pdev, hw);
+
+ hw->master = master;
+ hw->dev = dev;
+ hw->pdata = pdata;
+
+ spin_lock_init(&hw->lock);
+ init_completion(&hw->complete);
+ INIT_LIST_HEAD(&hw->msg_queue);
+ INIT_WORK(&hw->work, ti_ssp_spi_work);
+
+ hw->workqueue = create_singlethread_workqueue(dev_name(dev));
+ if (!hw->workqueue) {
+ error = -ENOMEM;
+ dev_err(dev, "work queue creation failed\n");
+ goto error_wq;
+ }
+
+ hw->ssp = ti_ssp_open(&hw->pdata->port_data);
+ if (IS_ERR(hw->ssp)) {
+ error = PTR_ERR(hw->ssp);
+ dev_err(dev, "ssp open failed (%d)\n", error);
+ goto error_open;
+ }
+
+ master->bus_num = pdev->id;
+ master->num_chipselect = hw->pdata->num_cs;
+ master->mode_bits = MODE_BITS;
+ master->flags = SPI_MASTER_HALF_DUPLEX;
+ master->setup = ti_ssp_spi_setup;
+ master->transfer = ti_ssp_spi_transfer;
+
+ error = spi_register_master(master);
+ if (error) {
+ dev_err(dev, "master registration failed\n");
+ goto error_reg;
+ }
+
+ return 0;
+
+error_reg:
+ ti_ssp_close(hw->ssp);
+error_open:
+ destroy_workqueue(hw->workqueue);
+error_wq:
+ spi_master_put(master);
+ return error;
+}
+
+static int __devexit ti_ssp_spi_remove(struct platform_device *pdev)
+{
+ struct ti_ssp_spi *hw = platform_get_drvdata(pdev);
+ int error;
+
+ hw->shutdown = 1;
+ while (!list_empty(&hw->msg_queue)) {
+ error = wait_for_completion_interruptible(&hw->complete);
+ if (error < 0) {
+ hw->shutdown = 0;
+ return error;
+ }
+ }
+
+ ti_ssp_close(hw->ssp);
+ destroy_workqueue(hw->workqueue);
+ spi_unregister_master(hw->master);
+
+ return 0;
+}
+
+static struct platform_driver ti_ssp_spi_driver = {
+ .probe = ti_ssp_spi_probe,
+ .remove = __devexit_p(ti_ssp_spi_remove),
+ .driver.name = "ti-ssp-spi",
+ .driver.owner = THIS_MODULE,
+};
+
+static int __init ti_ssp_spi_init(void)
+{
+ return platform_driver_register(&ti_ssp_spi_driver);
+}
+
+static void __exit ti_ssp_spi_exit(void)
+{
+ platform_driver_unregister(&ti_ssp_spi_driver);
+}
+
+subsys_initcall(ti_ssp_spi_init);
+module_exit(ti_ssp_spi_exit);
+
+MODULE_DESCRIPTION("SSP SPI Master");
+MODULE_AUTHOR("Cyril Chemparathy");
+MODULE_ALIAS("platform:spi_ti_ssp");
+MODULE_LICENSE("GPL");
--
1.7.0.4
------------------------------------------------------------------------------
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next prev parent reply other threads:[~2010-10-14 18:38 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-14 18:38 [PATCH 00/12] tnetv107x ssp driver stack Cyril Chemparathy
[not found] ` <1287081535-2864-1-git-send-email-cyril-l0cyMroinI0@public.gmane.org>
2010-10-14 18:38 ` [PATCH 01/12] misc: add driver for sequencer serial port Cyril Chemparathy
[not found] ` <1287081535-2864-2-git-send-email-cyril-l0cyMroinI0@public.gmane.org>
2010-10-16 5:00 ` Grant Likely
[not found] ` <20101016050055.GH21170-MrY2KI0G/OVr83L8+7iqerDks+cytr/Z@public.gmane.org>
2010-10-18 13:56 ` Cyril Chemparathy
[not found] ` <4CBC520B.9070502-l0cyMroinI0@public.gmane.org>
2010-10-18 14:59 ` Grant Likely
2010-10-14 18:38 ` [PATCH 02/12] davinci: add tnetv107x ssp platform device Cyril Chemparathy
2010-10-14 18:38 ` [PATCH 03/12] davinci: add ssp config for tnetv107x evm board Cyril Chemparathy
2010-10-14 18:38 ` Cyril Chemparathy [this message]
[not found] ` <1287081535-2864-5-git-send-email-cyril-l0cyMroinI0@public.gmane.org>
2010-10-16 5:05 ` [PATCH 04/12] spi: add ti-ssp spi master driver Grant Likely
2010-10-14 18:38 ` [PATCH 05/12] davinci: add spi devices on tnetv107x evm Cyril Chemparathy
2010-10-14 18:38 ` [PATCH 06/12] regulator: add driver for tps6524x regulator Cyril Chemparathy
[not found] ` <1287081535-2864-7-git-send-email-cyril-l0cyMroinI0@public.gmane.org>
2010-10-14 21:03 ` Mark Brown
[not found] ` <20101014210323.GB14479-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org>
2010-10-18 12:50 ` Cyril Chemparathy
2010-10-16 10:00 ` Mark Brown
2010-10-14 18:38 ` [PATCH 07/12] davinci: add tnetv107x evm regulators Cyril Chemparathy
[not found] ` <1287081535-2864-8-git-send-email-cyril-l0cyMroinI0@public.gmane.org>
2010-10-14 21:05 ` Mark Brown
2010-10-14 18:38 ` [PATCH 08/12] gpio: add ti-ssp virtual gpio driver Cyril Chemparathy
2010-10-14 18:38 ` [PATCH 09/12] davinci: add tnetv107x evm ti-ssp gpio device Cyril Chemparathy
2010-10-14 18:38 ` [PATCH 10/12] backlight: add support for tps6116x controller Cyril Chemparathy
2010-10-14 18:38 ` [PATCH 11/12] davinci: add tnetv107x evm backlight device Cyril Chemparathy
2010-10-14 18:38 ` [PATCH 12/12] davinci: add tnetv107x evm i2c eeprom device Cyril Chemparathy
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