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authorLinus Torvalds <torvalds@linux-foundation.org>2012-12-14 07:15:11 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-12-14 07:15:11 +0400
commitd3b43e12b2c8c69f79ab76dcdc5956f47c376378 (patch)
tree4fba9e425d7407e5abd5ab50d5ac09398ec5bff6 /drivers/spi/spi-clps711x.c
parent15de0599277f3477ddd11766282587f12d214252 (diff)
parent7cb943615aabbd72624f77f0a84b8c5d627cf846 (diff)
downloadlinux-d3b43e12b2c8c69f79ab76dcdc5956f47c376378.tar.xz
Merge tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6
Pull SPI updates from Grant Likely: "Primarily SPI device driver bug fixes, one removal of an old driver, and some new tegra support. There is some core code change too, but all in all pretty small stuff. The new features to note are: - Common code for describing GPIO CS lines in the device tree - Remove the SPI_BUFSIZ limitation on spi_write_the_read() - core spi ensures bits_per_word is set correctly - SPARC can now use SPI" * tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6: (36 commits) spi/sparc: Allow of_register_spi_devices for sparc spi: Remove HOTPLUG section attributes spi: Add support for specifying 3-wire mode via device tree spi: Fix comparison of different integer types spi/orion: Add SPI_CHPA and SPI_CPOL support to kirkwood driver. spi/sh: Add SH Mobile series as dependency to MSIOF controller spi/sh-msiof: Remove unneeded clock name spi: Remove SPI_BUFSIZ restriction on spi_write_then_read() spi/stmp: remove obsolete driver spi/clps711x: New SPI master driver spi: omap2-mcspi: remove duplicate inclusion of linux/err.h spi: omap2-mcspi: Fix the redifine warning spi/sh-hspi: add CS manual control support of_spi: add generic binding support to specify cs gpio spi: omap2-mcspi: remove duplicated include from spi-omap2-mcspi.c spi/bitbang: (cosmetic) simplify list manipulation spi/bitbang: avoid needless loop flow manipulations spi/omap: fix D0/D1 direction confusion spi: tegra: add spi driver for sflash controller spi: Dont call master->setup if not populated ...
Diffstat (limited to 'drivers/spi/spi-clps711x.c')
-rw-r--r--drivers/spi/spi-clps711x.c296
1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/spi/spi-clps711x.c b/drivers/spi/spi-clps711x.c
new file mode 100644
index 000000000000..1366c4620d5d
--- /dev/null
+++ b/drivers/spi/spi-clps711x.c
@@ -0,0 +1,296 @@
+/*
+ * CLPS711X SPI bus driver
+ *
+ * Copyright (C) 2012 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * 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.
+ */
+
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_data/spi-clps711x.h>
+
+#include <mach/hardware.h>
+
+#define DRIVER_NAME "spi-clps711x"
+
+struct spi_clps711x_data {
+ struct completion done;
+
+ struct clk *spi_clk;
+ u32 max_speed_hz;
+
+ u8 *tx_buf;
+ u8 *rx_buf;
+ int count;
+ int len;
+
+ int chipselect[0];
+};
+
+static int spi_clps711x_setup(struct spi_device *spi)
+{
+ struct spi_clps711x_data *hw = spi_master_get_devdata(spi->master);
+
+ if (spi->bits_per_word != 8) {
+ dev_err(&spi->dev, "Unsupported master bus width %i\n",
+ spi->bits_per_word);
+ return -EINVAL;
+ }
+
+ /* We are expect that SPI-device is not selected */
+ gpio_direction_output(hw->chipselect[spi->chip_select],
+ !(spi->mode & SPI_CS_HIGH));
+
+ return 0;
+}
+
+static void spi_clps711x_setup_mode(struct spi_device *spi)
+{
+ /* Setup edge for transfer */
+ if (spi->mode & SPI_CPHA)
+ clps_writew(clps_readw(SYSCON3) | SYSCON3_ADCCKNSEN, SYSCON3);
+ else
+ clps_writew(clps_readw(SYSCON3) & ~SYSCON3_ADCCKNSEN, SYSCON3);
+}
+
+static int spi_clps711x_setup_xfer(struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ u32 speed = xfer->speed_hz ? : spi->max_speed_hz;
+ u8 bpw = xfer->bits_per_word ? : spi->bits_per_word;
+ struct spi_clps711x_data *hw = spi_master_get_devdata(spi->master);
+
+ if (bpw != 8) {
+ dev_err(&spi->dev, "Unsupported master bus width %i\n", bpw);
+ return -EINVAL;
+ }
+
+ /* Setup SPI frequency divider */
+ if (!speed || (speed >= hw->max_speed_hz))
+ clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) |
+ SYSCON1_ADCKSEL(3), SYSCON1);
+ else if (speed >= (hw->max_speed_hz / 2))
+ clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) |
+ SYSCON1_ADCKSEL(2), SYSCON1);
+ else if (speed >= (hw->max_speed_hz / 8))
+ clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) |
+ SYSCON1_ADCKSEL(1), SYSCON1);
+ else
+ clps_writel((clps_readl(SYSCON1) & ~SYSCON1_ADCKSEL_MASK) |
+ SYSCON1_ADCKSEL(0), SYSCON1);
+
+ return 0;
+}
+
+static int spi_clps711x_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+ struct spi_transfer *xfer;
+ int status = 0, cs = hw->chipselect[msg->spi->chip_select];
+ u32 data;
+
+ spi_clps711x_setup_mode(msg->spi);
+
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ if (spi_clps711x_setup_xfer(msg->spi, xfer)) {
+ status = -EINVAL;
+ goto out_xfr;
+ }
+
+ gpio_set_value(cs, !!(msg->spi->mode & SPI_CS_HIGH));
+
+ INIT_COMPLETION(hw->done);
+
+ hw->count = 0;
+ hw->len = xfer->len;
+ hw->tx_buf = (u8 *)xfer->tx_buf;
+ hw->rx_buf = (u8 *)xfer->rx_buf;
+
+ /* Initiate transfer */
+ data = hw->tx_buf ? hw->tx_buf[hw->count] : 0;
+ clps_writel(data | SYNCIO_FRMLEN(8) | SYNCIO_TXFRMEN, SYNCIO);
+
+ wait_for_completion(&hw->done);
+
+ if (xfer->delay_usecs)
+ udelay(xfer->delay_usecs);
+
+ if (xfer->cs_change ||
+ list_is_last(&xfer->transfer_list, &msg->transfers))
+ gpio_set_value(cs, !(msg->spi->mode & SPI_CS_HIGH));
+
+ msg->actual_length += xfer->len;
+ }
+
+out_xfr:
+ msg->status = status;
+ spi_finalize_current_message(master);
+
+ return 0;
+}
+
+static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
+{
+ struct spi_clps711x_data *hw = (struct spi_clps711x_data *)dev_id;
+ u32 data;
+
+ /* Handle RX */
+ data = clps_readb(SYNCIO);
+ if (hw->rx_buf)
+ hw->rx_buf[hw->count] = (u8)data;
+
+ hw->count++;
+
+ /* Handle TX */
+ if (hw->count < hw->len) {
+ data = hw->tx_buf ? hw->tx_buf[hw->count] : 0;
+ clps_writel(data | SYNCIO_FRMLEN(8) | SYNCIO_TXFRMEN, SYNCIO);
+ } else
+ complete(&hw->done);
+
+ return IRQ_HANDLED;
+}
+
+static int spi_clps711x_probe(struct platform_device *pdev)
+{
+ int i, ret;
+ struct spi_master *master;
+ struct spi_clps711x_data *hw;
+ struct spi_clps711x_pdata *pdata = dev_get_platdata(&pdev->dev);
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "No platform data supplied\n");
+ return -EINVAL;
+ }
+
+ if (pdata->num_chipselect < 1) {
+ dev_err(&pdev->dev, "At least one CS must be defined\n");
+ return -EINVAL;
+ }
+
+ master = spi_alloc_master(&pdev->dev,
+ sizeof(struct spi_clps711x_data) +
+ sizeof(int) * pdata->num_chipselect);
+ if (!master) {
+ dev_err(&pdev->dev, "SPI allocating memory error\n");
+ return -ENOMEM;
+ }
+
+ master->bus_num = pdev->id;
+ master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
+ master->num_chipselect = pdata->num_chipselect;
+ master->setup = spi_clps711x_setup;
+ master->transfer_one_message = spi_clps711x_transfer_one_message;
+
+ hw = spi_master_get_devdata(master);
+
+ for (i = 0; i < master->num_chipselect; i++) {
+ hw->chipselect[i] = pdata->chipselect[i];
+ if (!gpio_is_valid(hw->chipselect[i])) {
+ dev_err(&pdev->dev, "Invalid CS GPIO %i\n", i);
+ ret = -EINVAL;
+ goto err_out;
+ }
+ if (gpio_request(hw->chipselect[i], DRIVER_NAME)) {
+ dev_err(&pdev->dev, "Can't get CS GPIO %i\n", i);
+ ret = -EINVAL;
+ goto err_out;
+ }
+ }
+
+ hw->spi_clk = devm_clk_get(&pdev->dev, "spi");
+ if (IS_ERR(hw->spi_clk)) {
+ dev_err(&pdev->dev, "Can't get clocks\n");
+ ret = PTR_ERR(hw->spi_clk);
+ goto err_out;
+ }
+ hw->max_speed_hz = clk_get_rate(hw->spi_clk);
+
+ init_completion(&hw->done);
+ platform_set_drvdata(pdev, master);
+
+ /* Disable extended mode due hardware problems */
+ clps_writew(clps_readw(SYSCON3) & ~SYSCON3_ADCCON, SYSCON3);
+
+ /* Clear possible pending interrupt */
+ clps_readl(SYNCIO);
+
+ ret = devm_request_irq(&pdev->dev, IRQ_SSEOTI, spi_clps711x_isr, 0,
+ dev_name(&pdev->dev), hw);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't request IRQ\n");
+ clk_put(hw->spi_clk);
+ goto clk_out;
+ }
+
+ ret = spi_register_master(master);
+ if (!ret) {
+ dev_info(&pdev->dev,
+ "SPI bus driver initialized. Master clock %u Hz\n",
+ hw->max_speed_hz);
+ return 0;
+ }
+
+ dev_err(&pdev->dev, "Failed to register master\n");
+ devm_free_irq(&pdev->dev, IRQ_SSEOTI, hw);
+
+clk_out:
+ devm_clk_put(&pdev->dev, hw->spi_clk);
+
+err_out:
+ while (--i >= 0)
+ if (gpio_is_valid(hw->chipselect[i]))
+ gpio_free(hw->chipselect[i]);
+
+ platform_set_drvdata(pdev, NULL);
+ spi_master_put(master);
+ kfree(master);
+
+ return ret;
+}
+
+static int spi_clps711x_remove(struct platform_device *pdev)
+{
+ int i;
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+
+ devm_free_irq(&pdev->dev, IRQ_SSEOTI, hw);
+
+ for (i = 0; i < master->num_chipselect; i++)
+ if (gpio_is_valid(hw->chipselect[i]))
+ gpio_free(hw->chipselect[i]);
+
+ devm_clk_put(&pdev->dev, hw->spi_clk);
+ platform_set_drvdata(pdev, NULL);
+ spi_unregister_master(master);
+ kfree(master);
+
+ return 0;
+}
+
+static struct platform_driver clps711x_spi_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = spi_clps711x_probe,
+ .remove = spi_clps711x_remove,
+};
+module_platform_driver(clps711x_spi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("CLPS711X SPI bus driver");