+++ /dev/null
-From 86cb7c7ab176112f8b0031dc7c8d19103ba52277 Mon Sep 17 00:00:00 2001
-From: Maxime Ripard <maxime.ripard@free-electrons.com>
-Date: Wed, 5 Feb 2014 14:05:05 +0100
-Subject: [PATCH] spi: sunxi: Add Allwinner A31 SPI controller driver
-
-The Allwinner A31 has a new SPI controller IP compared to the older Allwinner
-SoCs.
-
-It supports DMA, but the driver only does PIO for now, and DMA will be
-supported eventually.
-
-Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
----
- .../devicetree/bindings/spi/spi-sun6i.txt | 24 +
- drivers/spi/Kconfig | 6 +
- drivers/spi/Makefile | 1 +
- drivers/spi/spi-sun6i.c | 483 +++++++++++++++++++++
- 4 files changed, 514 insertions(+)
- create mode 100644 Documentation/devicetree/bindings/spi/spi-sun6i.txt
- create mode 100644 drivers/spi/spi-sun6i.c
-
---- /dev/null
-+++ b/Documentation/devicetree/bindings/spi/spi-sun6i.txt
-@@ -0,0 +1,24 @@
-+Allwinner A31 SPI controller
-+
-+Required properties:
-+- compatible: Should be "allwinner,sun6i-a31-spi".
-+- reg: Should contain register location and length.
-+- interrupts: Should contain interrupt.
-+- clocks: phandle to the clocks feeding the SPI controller. Two are
-+ needed:
-+ - "ahb": the gated AHB parent clock
-+ - "mod": the parent module clock
-+- clock-names: Must contain the clock names described just above
-+- resets: phandle to the reset controller asserting this device in
-+ reset
-+
-+Example:
-+
-+spi1: spi@01c69000 {
-+ compatible = "allwinner,sun6i-a31-spi";
-+ reg = <0x01c69000 0x1000>;
-+ interrupts = <0 66 4>;
-+ clocks = <&ahb1_gates 21>, <&spi1_clk>;
-+ clock-names = "ahb", "mod";
-+ resets = <&ahb1_rst 21>;
-+};
---- a/drivers/spi/Kconfig
-+++ b/drivers/spi/Kconfig
-@@ -455,6 +455,12 @@ config SPI_SIRF
- help
- SPI driver for CSR SiRFprimaII SoCs
-
-+config SPI_SUN6I
-+ tristate "Allwinner A31 SPI controller"
-+ depends on ARCH_SUNXI || COMPILE_TEST
-+ help
-+ This enables using the SPI controller on the Allwinner A31 SoCs.
-+
- config SPI_MXS
- tristate "Freescale MXS SPI controller"
- depends on ARCH_MXS
---- a/drivers/spi/Makefile
-+++ b/drivers/spi/Makefile
-@@ -71,6 +71,7 @@ obj-$(CONFIG_SPI_SH_HSPI) += spi-sh-hsp
- obj-$(CONFIG_SPI_SH_MSIOF) += spi-sh-msiof.o
- obj-$(CONFIG_SPI_SH_SCI) += spi-sh-sci.o
- obj-$(CONFIG_SPI_SIRF) += spi-sirf.o
-+obj-$(CONFIG_SPI_SUN6I) += spi-sun6i.o
- obj-$(CONFIG_SPI_TEGRA114) += spi-tegra114.o
- obj-$(CONFIG_SPI_TEGRA20_SFLASH) += spi-tegra20-sflash.o
- obj-$(CONFIG_SPI_TEGRA20_SLINK) += spi-tegra20-slink.o
---- /dev/null
-+++ b/drivers/spi/spi-sun6i.c
-@@ -0,0 +1,483 @@
-+/*
-+ * Copyright (C) 2012 - 2014 Allwinner Tech
-+ * Pan Nan <pannan@allwinnertech.com>
-+ *
-+ * Copyright (C) 2014 Maxime Ripard
-+ * Maxime Ripard <maxime.ripard@free-electrons.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.
-+ */
-+
-+#include <linux/clk.h>
-+#include <linux/delay.h>
-+#include <linux/device.h>
-+#include <linux/interrupt.h>
-+#include <linux/io.h>
-+#include <linux/module.h>
-+#include <linux/platform_device.h>
-+#include <linux/pm_runtime.h>
-+#include <linux/reset.h>
-+#include <linux/workqueue.h>
-+
-+#include <linux/spi/spi.h>
-+
-+#define SUN6I_FIFO_DEPTH 128
-+
-+#define SUN6I_GBL_CTL_REG 0x04
-+#define SUN6I_GBL_CTL_BUS_ENABLE BIT(0)
-+#define SUN6I_GBL_CTL_MASTER BIT(1)
-+#define SUN6I_GBL_CTL_TP BIT(7)
-+#define SUN6I_GBL_CTL_RST BIT(31)
-+
-+#define SUN6I_TFR_CTL_REG 0x08
-+#define SUN6I_TFR_CTL_CPHA BIT(0)
-+#define SUN6I_TFR_CTL_CPOL BIT(1)
-+#define SUN6I_TFR_CTL_SPOL BIT(2)
-+#define SUN6I_TFR_CTL_CS_MASK 0x3
-+#define SUN6I_TFR_CTL_CS(cs) (((cs) & SUN6I_TFR_CTL_CS_MASK) << 4)
-+#define SUN6I_TFR_CTL_CS_MANUAL BIT(6)
-+#define SUN6I_TFR_CTL_CS_LEVEL BIT(7)
-+#define SUN6I_TFR_CTL_DHB BIT(8)
-+#define SUN6I_TFR_CTL_FBS BIT(12)
-+#define SUN6I_TFR_CTL_XCH BIT(31)
-+
-+#define SUN6I_INT_CTL_REG 0x10
-+#define SUN6I_INT_CTL_RF_OVF BIT(8)
-+#define SUN6I_INT_CTL_TC BIT(12)
-+
-+#define SUN6I_INT_STA_REG 0x14
-+
-+#define SUN6I_FIFO_CTL_REG 0x18
-+#define SUN6I_FIFO_CTL_RF_RST BIT(15)
-+#define SUN6I_FIFO_CTL_TF_RST BIT(31)
-+
-+#define SUN6I_FIFO_STA_REG 0x1c
-+#define SUN6I_FIFO_STA_RF_CNT_MASK 0x7f
-+#define SUN6I_FIFO_STA_RF_CNT_BITS 0
-+#define SUN6I_FIFO_STA_TF_CNT_MASK 0x7f
-+#define SUN6I_FIFO_STA_TF_CNT_BITS 16
-+
-+#define SUN6I_CLK_CTL_REG 0x24
-+#define SUN6I_CLK_CTL_CDR2_MASK 0xff
-+#define SUN6I_CLK_CTL_CDR2(div) (((div) & SUN6I_CLK_CTL_CDR2_MASK) << 0)
-+#define SUN6I_CLK_CTL_CDR1_MASK 0xf
-+#define SUN6I_CLK_CTL_CDR1(div) (((div) & SUN6I_CLK_CTL_CDR1_MASK) << 8)
-+#define SUN6I_CLK_CTL_DRS BIT(12)
-+
-+#define SUN6I_BURST_CNT_REG 0x30
-+#define SUN6I_BURST_CNT(cnt) ((cnt) & 0xffffff)
-+
-+#define SUN6I_XMIT_CNT_REG 0x34
-+#define SUN6I_XMIT_CNT(cnt) ((cnt) & 0xffffff)
-+
-+#define SUN6I_BURST_CTL_CNT_REG 0x38
-+#define SUN6I_BURST_CTL_CNT_STC(cnt) ((cnt) & 0xffffff)
-+
-+#define SUN6I_TXDATA_REG 0x200
-+#define SUN6I_RXDATA_REG 0x300
-+
-+struct sun6i_spi {
-+ struct spi_master *master;
-+ void __iomem *base_addr;
-+ struct clk *hclk;
-+ struct clk *mclk;
-+ struct reset_control *rstc;
-+
-+ struct completion done;
-+
-+ const u8 *tx_buf;
-+ u8 *rx_buf;
-+ int len;
-+};
-+
-+static inline u32 sun6i_spi_read(struct sun6i_spi *sspi, u32 reg)
-+{
-+ return readl(sspi->base_addr + reg);
-+}
-+
-+static inline void sun6i_spi_write(struct sun6i_spi *sspi, u32 reg, u32 value)
-+{
-+ writel(value, sspi->base_addr + reg);
-+}
-+
-+static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi, int len)
-+{
-+ u32 reg, cnt;
-+ u8 byte;
-+
-+ /* See how much data is available */
-+ reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
-+ reg &= SUN6I_FIFO_STA_RF_CNT_MASK;
-+ cnt = reg >> SUN6I_FIFO_STA_RF_CNT_BITS;
-+
-+ if (len > cnt)
-+ len = cnt;
-+
-+ while (len--) {
-+ byte = readb(sspi->base_addr + SUN6I_RXDATA_REG);
-+ if (sspi->rx_buf)
-+ *sspi->rx_buf++ = byte;
-+ }
-+}
-+
-+static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi, int len)
-+{
-+ u8 byte;
-+
-+ if (len > sspi->len)
-+ len = sspi->len;
-+
-+ while (len--) {
-+ byte = sspi->tx_buf ? *sspi->tx_buf++ : 0;
-+ writeb(byte, sspi->base_addr + SUN6I_TXDATA_REG);
-+ sspi->len--;
-+ }
-+}
-+
-+static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
-+{
-+ struct sun6i_spi *sspi = spi_master_get_devdata(spi->master);
-+ u32 reg;
-+
-+ reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
-+ reg &= ~SUN6I_TFR_CTL_CS_MASK;
-+ reg |= SUN6I_TFR_CTL_CS(spi->chip_select);
-+
-+ if (enable)
-+ reg |= SUN6I_TFR_CTL_CS_LEVEL;
-+ else
-+ reg &= ~SUN6I_TFR_CTL_CS_LEVEL;
-+
-+ sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
-+}
-+
-+
-+static int sun6i_spi_transfer_one(struct spi_master *master,
-+ struct spi_device *spi,
-+ struct spi_transfer *tfr)
-+{
-+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
-+ unsigned int mclk_rate, div, timeout;
-+ unsigned int tx_len = 0;
-+ int ret = 0;
-+ u32 reg;
-+
-+ /* We don't support transfer larger than the FIFO */
-+ if (tfr->len > SUN6I_FIFO_DEPTH)
-+ return -EINVAL;
-+
-+ reinit_completion(&sspi->done);
-+ sspi->tx_buf = tfr->tx_buf;
-+ sspi->rx_buf = tfr->rx_buf;
-+ sspi->len = tfr->len;
-+
-+ /* Clear pending interrupts */
-+ sun6i_spi_write(sspi, SUN6I_INT_STA_REG, ~0);
-+
-+ /* Reset FIFO */
-+ sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
-+ SUN6I_FIFO_CTL_RF_RST | SUN6I_FIFO_CTL_TF_RST);
-+
-+ /*
-+ * Setup the transfer control register: Chip Select,
-+ * polarities, etc.
-+ */
-+ reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
-+
-+ if (spi->mode & SPI_CPOL)
-+ reg |= SUN6I_TFR_CTL_CPOL;
-+ else
-+ reg &= ~SUN6I_TFR_CTL_CPOL;
-+
-+ if (spi->mode & SPI_CPHA)
-+ reg |= SUN6I_TFR_CTL_CPHA;
-+ else
-+ reg &= ~SUN6I_TFR_CTL_CPHA;
-+
-+ if (spi->mode & SPI_LSB_FIRST)
-+ reg |= SUN6I_TFR_CTL_FBS;
-+ else
-+ reg &= ~SUN6I_TFR_CTL_FBS;
-+
-+ /*
-+ * If it's a TX only transfer, we don't want to fill the RX
-+ * FIFO with bogus data
-+ */
-+ if (sspi->rx_buf)
-+ reg &= ~SUN6I_TFR_CTL_DHB;
-+ else
-+ reg |= SUN6I_TFR_CTL_DHB;
-+
-+ /* We want to control the chip select manually */
-+ reg |= SUN6I_TFR_CTL_CS_MANUAL;
-+
-+ sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
-+
-+ /* Ensure that we have a parent clock fast enough */
-+ mclk_rate = clk_get_rate(sspi->mclk);
-+ if (mclk_rate < (2 * spi->max_speed_hz)) {
-+ clk_set_rate(sspi->mclk, 2 * spi->max_speed_hz);
-+ mclk_rate = clk_get_rate(sspi->mclk);
-+ }
-+
-+ /*
-+ * Setup clock divider.
-+ *
-+ * We have two choices there. Either we can use the clock
-+ * divide rate 1, which is calculated thanks to this formula:
-+ * SPI_CLK = MOD_CLK / (2 ^ cdr)
-+ * Or we can use CDR2, which is calculated with the formula:
-+ * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
-+ * Wether we use the former or the latter is set through the
-+ * DRS bit.
-+ *
-+ * First try CDR2, and if we can't reach the expected
-+ * frequency, fall back to CDR1.
-+ */
-+ div = mclk_rate / (2 * spi->max_speed_hz);
-+ if (div <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
-+ if (div > 0)
-+ div--;
-+
-+ reg = SUN6I_CLK_CTL_CDR2(div) | SUN6I_CLK_CTL_DRS;
-+ } else {
-+ div = ilog2(mclk_rate) - ilog2(spi->max_speed_hz);
-+ reg = SUN6I_CLK_CTL_CDR1(div);
-+ }
-+
-+ sun6i_spi_write(sspi, SUN6I_CLK_CTL_REG, reg);
-+
-+ /* Setup the transfer now... */
-+ if (sspi->tx_buf)
-+ tx_len = tfr->len;
-+
-+ /* Setup the counters */
-+ sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, SUN6I_BURST_CNT(tfr->len));
-+ sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, SUN6I_XMIT_CNT(tx_len));
-+ sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG,
-+ SUN6I_BURST_CTL_CNT_STC(tx_len));
-+
-+ /* Fill the TX FIFO */
-+ sun6i_spi_fill_fifo(sspi, SUN6I_FIFO_DEPTH);
-+
-+ /* Enable the interrupts */
-+ sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, SUN6I_INT_CTL_TC);
-+
-+ /* Start the transfer */
-+ reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
-+ sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg | SUN6I_TFR_CTL_XCH);
-+
-+ timeout = wait_for_completion_timeout(&sspi->done,
-+ msecs_to_jiffies(1000));
-+ if (!timeout) {
-+ ret = -ETIMEDOUT;
-+ goto out;
-+ }
-+
-+ sun6i_spi_drain_fifo(sspi, SUN6I_FIFO_DEPTH);
-+
-+out:
-+ sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
-+
-+ return ret;
-+}
-+
-+static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
-+{
-+ struct sun6i_spi *sspi = dev_id;
-+ u32 status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG);
-+
-+ /* Transfer complete */
-+ if (status & SUN6I_INT_CTL_TC) {
-+ sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TC);
-+ complete(&sspi->done);
-+ return IRQ_HANDLED;
-+ }
-+
-+ return IRQ_NONE;
-+}
-+
-+static int sun6i_spi_runtime_resume(struct device *dev)
-+{
-+ struct spi_master *master = dev_get_drvdata(dev);
-+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
-+ int ret;
-+
-+ ret = clk_prepare_enable(sspi->hclk);
-+ if (ret) {
-+ dev_err(dev, "Couldn't enable AHB clock\n");
-+ goto out;
-+ }
-+
-+ ret = clk_prepare_enable(sspi->mclk);
-+ if (ret) {
-+ dev_err(dev, "Couldn't enable module clock\n");
-+ goto err;
-+ }
-+
-+ ret = reset_control_deassert(sspi->rstc);
-+ if (ret) {
-+ dev_err(dev, "Couldn't deassert the device from reset\n");
-+ goto err2;
-+ }
-+
-+ sun6i_spi_write(sspi, SUN6I_GBL_CTL_REG,
-+ SUN6I_GBL_CTL_BUS_ENABLE | SUN6I_GBL_CTL_MASTER | SUN6I_GBL_CTL_TP);
-+
-+ return 0;
-+
-+err2:
-+ clk_disable_unprepare(sspi->mclk);
-+err:
-+ clk_disable_unprepare(sspi->hclk);
-+out:
-+ return ret;
-+}
-+
-+static int sun6i_spi_runtime_suspend(struct device *dev)
-+{
-+ struct spi_master *master = dev_get_drvdata(dev);
-+ struct sun6i_spi *sspi = spi_master_get_devdata(master);
-+
-+ reset_control_assert(sspi->rstc);
-+ clk_disable_unprepare(sspi->mclk);
-+ clk_disable_unprepare(sspi->hclk);
-+
-+ return 0;
-+}
-+
-+static int sun6i_spi_probe(struct platform_device *pdev)
-+{
-+ struct spi_master *master;
-+ struct sun6i_spi *sspi;
-+ struct resource *res;
-+ int ret = 0, irq;
-+
-+ master = spi_alloc_master(&pdev->dev, sizeof(struct sun6i_spi));
-+ if (!master) {
-+ dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
-+ return -ENOMEM;
-+ }
-+
-+ platform_set_drvdata(pdev, master);
-+ sspi = spi_master_get_devdata(master);
-+
-+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-+ sspi->base_addr = devm_ioremap_resource(&pdev->dev, res);
-+ if (IS_ERR(sspi->base_addr)) {
-+ ret = PTR_ERR(sspi->base_addr);
-+ goto err_free_master;
-+ }
-+
-+ irq = platform_get_irq(pdev, 0);
-+ if (irq < 0) {
-+ dev_err(&pdev->dev, "No spi IRQ specified\n");
-+ ret = -ENXIO;
-+ goto err_free_master;
-+ }
-+
-+ ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
-+ 0, "sun6i-spi", sspi);
-+ if (ret) {
-+ dev_err(&pdev->dev, "Cannot request IRQ\n");
-+ goto err_free_master;
-+ }
-+
-+ sspi->master = master;
-+ master->set_cs = sun6i_spi_set_cs;
-+ master->transfer_one = sun6i_spi_transfer_one;
-+ master->num_chipselect = 4;
-+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
-+ master->dev.of_node = pdev->dev.of_node;
-+ master->auto_runtime_pm = true;
-+
-+ sspi->hclk = devm_clk_get(&pdev->dev, "ahb");
-+ if (IS_ERR(sspi->hclk)) {
-+ dev_err(&pdev->dev, "Unable to acquire AHB clock\n");
-+ ret = PTR_ERR(sspi->hclk);
-+ goto err_free_master;
-+ }
-+
-+ sspi->mclk = devm_clk_get(&pdev->dev, "mod");
-+ if (IS_ERR(sspi->mclk)) {
-+ dev_err(&pdev->dev, "Unable to acquire module clock\n");
-+ ret = PTR_ERR(sspi->mclk);
-+ goto err_free_master;
-+ }
-+
-+ init_completion(&sspi->done);
-+
-+ sspi->rstc = devm_reset_control_get(&pdev->dev, NULL);
-+ if (IS_ERR(sspi->rstc)) {
-+ dev_err(&pdev->dev, "Couldn't get reset controller\n");
-+ ret = PTR_ERR(sspi->rstc);
-+ goto err_free_master;
-+ }
-+
-+ /*
-+ * This wake-up/shutdown pattern is to be able to have the
-+ * device woken up, even if runtime_pm is disabled
-+ */
-+ ret = sun6i_spi_runtime_resume(&pdev->dev);
-+ if (ret) {
-+ dev_err(&pdev->dev, "Couldn't resume the device\n");
-+ goto err_free_master;
-+ }
-+
-+ pm_runtime_set_active(&pdev->dev);
-+ pm_runtime_enable(&pdev->dev);
-+ pm_runtime_idle(&pdev->dev);
-+
-+ ret = devm_spi_register_master(&pdev->dev, master);
-+ if (ret) {
-+ dev_err(&pdev->dev, "cannot register SPI master\n");
-+ goto err_pm_disable;
-+ }
-+
-+ return 0;
-+
-+err_pm_disable:
-+ pm_runtime_disable(&pdev->dev);
-+ sun6i_spi_runtime_suspend(&pdev->dev);
-+err_free_master:
-+ spi_master_put(master);
-+ return ret;
-+}
-+
-+static int sun6i_spi_remove(struct platform_device *pdev)
-+{
-+ pm_runtime_disable(&pdev->dev);
-+
-+ return 0;
-+}
-+
-+static const struct of_device_id sun6i_spi_match[] = {
-+ { .compatible = "allwinner,sun6i-a31-spi", },
-+ {}
-+};
-+MODULE_DEVICE_TABLE(of, sun6i_spi_match);
-+
-+static const struct dev_pm_ops sun6i_spi_pm_ops = {
-+ .runtime_resume = sun6i_spi_runtime_resume,
-+ .runtime_suspend = sun6i_spi_runtime_suspend,
-+};
-+
-+static struct platform_driver sun6i_spi_driver = {
-+ .probe = sun6i_spi_probe,
-+ .remove = sun6i_spi_remove,
-+ .driver = {
-+ .name = "sun6i-spi",
-+ .owner = THIS_MODULE,
-+ .of_match_table = sun6i_spi_match,
-+ .pm = &sun6i_spi_pm_ops,
-+ },
-+};
-+module_platform_driver(sun6i_spi_driver);
-+
-+MODULE_AUTHOR("Pan Nan <pannan@allwinnertech.com>");
-+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
-+MODULE_DESCRIPTION("Allwinner A31 SPI controller driver");
-+MODULE_LICENSE("GPL");
projects / openwrt / openwrt.git / blobdiff