From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cyril Chemparathy Subject: [PATCH v7 04/12] spi: add ti-ssp spi master driver Date: Tue, 7 Dec 2010 09:51:54 -0500 Message-ID: <1291733522-3626-5-git-send-email-cyril@ti.com> References: <1291733522-3626-1-git-send-email-cyril@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: dbrownell-Rn4VEauK+AKRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, khilman-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org, Cyril Chemparathy , akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, alan-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org To: davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org, spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, sameo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, lrg-kDsPt+C1G03kYMGBc/C6ZA@public.gmane.org, broonie-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org, rpurdie@rpsys Return-path: In-Reply-To: <1291733522-3626-1-git-send-email-cyril-l0cyMroinI0@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org This patch adds an SPI master implementation that operates on top of an underlying TI-SSP port. Signed-off-by: Cyril Chemparathy --- drivers/spi/Kconfig | 10 + drivers/spi/Makefile | 1 + drivers/spi/ti-ssp-spi.c | 402 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/mfd/ti_ssp.h | 6 + 4 files changed, 419 insertions(+), 0 deletions(-) create mode 100644 drivers/spi/ti-ssp-spi.c diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 78f9fd0..7f0ed2a 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -336,6 +336,16 @@ config SPI_TEGRA help SPI driver for NVidia Tegra SoCs +config SPI_TI_SSP + tristate "TI Sequencer Serial Port - SPI Support" + depends on MFD_TI_SSP + help + This selects an SPI master implementation using a TI sequencer + serial port. + + To compile this driver as a module, choose M here: the + module will be called ti-ssp-spi. + config SPI_TOPCLIFF_PCH tristate "Topcliff PCH SPI Controller" depends on PCI diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 8bc1a5a..595e5b8 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_TEGRA) += spi_tegra.o +obj-$(CONFIG_SPI_TI_SSP) += ti-ssp-spi.o obj-$(CONFIG_SPI_TOPCLIFF_PCH) += spi_topcliff_pch.o obj-$(CONFIG_SPI_TXX9) += spi_txx9.o obj-$(CONFIG_SPI_XILINX) += xilinx_spi.o diff --git a/drivers/spi/ti-ssp-spi.c b/drivers/spi/ti-ssp-spi.c new file mode 100644 index 0000000..30fc0e2 --- /dev/null +++ b/drivers/spi/ti-ssp-spi.c @@ -0,0 +1,402 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include + +#define MODE_BITS (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH) + +struct ti_ssp_spi { + const struct ti_ssp_spi_data *pdata; + struct spi_master *master; + 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; + 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->dev, hw->pc_rd, 0, &ret); + return ret; +} + +static void do_write_data(struct ti_ssp_spi *hw, u32 data) +{ + ti_ssp_run(hw->dev, 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->dev, 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->dev, 0, seqram, idx); + if (error < 0) + return error; + + error = ti_ssp_set_mode(hw->dev, ((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(&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); + + spin_unlock(&hw->lock); + + 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); + + xfer_status = do_transfer(hw, m, t); + if (xfer_status < 0) + status = xfer_status; + + if (t->delay_usecs) + udelay(t->delay_usecs); + + if (t->cs_change) + chip_select(hw, 0); + } + + chip_select(hw, 0); + m->status = status; + m->complete(m->context); + + spin_lock(&hw->lock); + } + + if (hw->shutdown) + complete(&hw->complete); + + spin_unlock(&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; + 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(&hw->lock); + 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(&hw->lock); + 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; + } + + error = ti_ssp_set_iosel(hw->dev, hw->pdata->iosel); + if (error < 0) { + dev_err(dev, "io setup failed\n"); + goto error_iosel; + } + + 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: +error_iosel: + 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; + } + } + 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", + .owner = THIS_MODULE, + }, +}; + +static int __init ti_ssp_spi_init(void) +{ + return platform_driver_register(&ti_ssp_spi_driver); +} +module_init(ti_ssp_spi_init); + +static void __exit ti_ssp_spi_exit(void) +{ + platform_driver_unregister(&ti_ssp_spi_driver); +} +module_exit(ti_ssp_spi_exit); + +MODULE_DESCRIPTION("SSP SPI Master"); +MODULE_AUTHOR("Cyril Chemparathy"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:ti-ssp-spi"); diff --git a/include/linux/mfd/ti_ssp.h b/include/linux/mfd/ti_ssp.h index 021fe09..dbb4b43 100644 --- a/include/linux/mfd/ti_ssp.h +++ b/include/linux/mfd/ti_ssp.h @@ -32,6 +32,12 @@ struct ti_ssp_data { struct ti_ssp_dev_data dev_data[2]; }; +struct ti_ssp_spi_data { + unsigned long iosel; + int num_cs; + void (*select)(int cs); +}; + /* * Sequencer port IO pin configuration bits. These do not correlate 1-1 with * the hardware. The iosel field in the port data combines iosel1 and iosel2, -- 1.7.1 ------------------------------------------------------------------------------ What happens now with your Lotus Notes apps - do you make another costly upgrade, or settle for being marooned without product support? Time to move off Lotus Notes and onto the cloud with Force.com, apps are easier to build, use, and manage than apps on traditional platforms. Sign up for the Lotus Notes Migration Kit to learn more. http://p.sf.net/sfu/salesforce-d2d