From: Maxime Ripard <maxime.ripard@free-electrons.com>
To: Mark Brown <broonie@kernel.org>,
Mike Turquette <mturquette@linaro.org>,
Emilio Lopez <emilio@elopez.com.ar>
Cc: linux-sunxi@googlegroups.com, linux-spi@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, kevin.z.m.zh@gmail.com,
sunny@allwinnertech.com, shuge@allwinnertech.com,
zhuzhenhua@allwinnertech.com,
Maxime Ripard <maxime.ripard@free-electrons.com>
Subject: [PATCH v3 3/5] spi: sunxi: Add Allwinner A31 SPI controller driver
Date: Fri, 31 Jan 2014 11:55:50 +0100 [thread overview]
Message-ID: <1391165752-1819-4-git-send-email-maxime.ripard@free-electrons.com> (raw)
In-Reply-To: <1391165752-1819-1-git-send-email-maxime.ripard@free-electrons.com>
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 | 473 +++++++++++++++++++++
4 files changed, 504 insertions(+)
create mode 100644 Documentation/devicetree/bindings/spi/spi-sun6i.txt
create mode 100644 drivers/spi/spi-sun6i.c
diff --git a/Documentation/devicetree/bindings/spi/spi-sun6i.txt b/Documentation/devicetree/bindings/spi/spi-sun6i.txt
new file mode 100644
index 0000000..21de73d
--- /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>;
+};
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 5072b71..24f3b85 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -446,6 +446,12 @@ 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
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 95af48d..13b6ccf 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_SPI_SH_HSPI) += spi-sh-hspi.o
obj-$(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
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
new file mode 100644
index 0000000..1747892
--- /dev/null
+++ b/drivers/spi/spi-sun6i.c
@@ -0,0 +1,473 @@
+/*
+ * 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 = devm_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))
+ return PTR_ERR(sspi->base_addr);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "No spi IRQ specified\n");
+ return -ENXIO;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
+ 0, "sun6i-spi", sspi);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot request IRQ\n");
+ return ret;
+ }
+
+ sspi->master = master;
+ master->bus_num = -1;
+ 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");
+ return PTR_ERR(sspi->hclk);
+ }
+
+ sspi->mclk = devm_clk_get(&pdev->dev, "mod");
+ if (IS_ERR(sspi->mclk)) {
+ dev_err(&pdev->dev, "Unable to acquire module clock\n");
+ return PTR_ERR(sspi->mclk);
+ }
+
+ 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");
+ return PTR_ERR(sspi->rstc);
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ if (!pm_runtime_enabled(&pdev->dev)) {
+ ret = sun6i_spi_runtime_resume(&pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Couldn't resume the device\n");
+ return ret;
+ }
+ }
+
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (ret) {
+ dev_err(&pdev->dev, "cannot register SPI master\n");
+ goto err;
+ }
+
+ return 0;
+
+err:
+ if (!pm_runtime_enabled(&pdev->dev))
+ sun6i_spi_runtime_suspend(&pdev->dev);
+
+ pm_runtime_disable(&pdev->dev);
+ 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");
--
1.8.4.2
WARNING: multiple messages have this Message-ID (diff)
From: Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
To: Mark Brown <broonie-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Mike Turquette
<mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
Emilio Lopez <emilio-0Z03zUJReD5OxF6Tv1QG9Q@public.gmane.org>
Cc: linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org,
linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
kevin.z.m.zh-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
sunny-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org,
shuge-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org,
zhuzhenhua-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org,
Maxime Ripard
<maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Subject: [PATCH v3 3/5] spi: sunxi: Add Allwinner A31 SPI controller driver
Date: Fri, 31 Jan 2014 11:55:50 +0100 [thread overview]
Message-ID: <1391165752-1819-4-git-send-email-maxime.ripard@free-electrons.com> (raw)
In-Reply-To: <1391165752-1819-1-git-send-email-maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
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-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
.../devicetree/bindings/spi/spi-sun6i.txt | 24 ++
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-sun6i.c | 473 +++++++++++++++++++++
4 files changed, 504 insertions(+)
create mode 100644 Documentation/devicetree/bindings/spi/spi-sun6i.txt
create mode 100644 drivers/spi/spi-sun6i.c
diff --git a/Documentation/devicetree/bindings/spi/spi-sun6i.txt b/Documentation/devicetree/bindings/spi/spi-sun6i.txt
new file mode 100644
index 0000000..21de73d
--- /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>;
+};
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 5072b71..24f3b85 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -446,6 +446,12 @@ 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
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 95af48d..13b6ccf 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_SPI_SH_HSPI) += spi-sh-hspi.o
obj-$(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
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
new file mode 100644
index 0000000..1747892
--- /dev/null
+++ b/drivers/spi/spi-sun6i.c
@@ -0,0 +1,473 @@
+/*
+ * Copyright (C) 2012 - 2014 Allwinner Tech
+ * Pan Nan <pannan-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org>
+ *
+ * Copyright (C) 2014 Maxime Ripard
+ * Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
+ *
+ * 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 = devm_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))
+ return PTR_ERR(sspi->base_addr);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "No spi IRQ specified\n");
+ return -ENXIO;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
+ 0, "sun6i-spi", sspi);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot request IRQ\n");
+ return ret;
+ }
+
+ sspi->master = master;
+ master->bus_num = -1;
+ 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");
+ return PTR_ERR(sspi->hclk);
+ }
+
+ sspi->mclk = devm_clk_get(&pdev->dev, "mod");
+ if (IS_ERR(sspi->mclk)) {
+ dev_err(&pdev->dev, "Unable to acquire module clock\n");
+ return PTR_ERR(sspi->mclk);
+ }
+
+ 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");
+ return PTR_ERR(sspi->rstc);
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ if (!pm_runtime_enabled(&pdev->dev)) {
+ ret = sun6i_spi_runtime_resume(&pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Couldn't resume the device\n");
+ return ret;
+ }
+ }
+
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (ret) {
+ dev_err(&pdev->dev, "cannot register SPI master\n");
+ goto err;
+ }
+
+ return 0;
+
+err:
+ if (!pm_runtime_enabled(&pdev->dev))
+ sun6i_spi_runtime_suspend(&pdev->dev);
+
+ pm_runtime_disable(&pdev->dev);
+ 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-0TFLnhJekD6UEPyfVivIlAC/G2K4zDHf@public.gmane.org>");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>");
+MODULE_DESCRIPTION("Allwinner A31 SPI controller driver");
+MODULE_LICENSE("GPL");
--
1.8.4.2
WARNING: multiple messages have this Message-ID (diff)
From: maxime.ripard@free-electrons.com (Maxime Ripard)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 3/5] spi: sunxi: Add Allwinner A31 SPI controller driver
Date: Fri, 31 Jan 2014 11:55:50 +0100 [thread overview]
Message-ID: <1391165752-1819-4-git-send-email-maxime.ripard@free-electrons.com> (raw)
In-Reply-To: <1391165752-1819-1-git-send-email-maxime.ripard@free-electrons.com>
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 | 473 +++++++++++++++++++++
4 files changed, 504 insertions(+)
create mode 100644 Documentation/devicetree/bindings/spi/spi-sun6i.txt
create mode 100644 drivers/spi/spi-sun6i.c
diff --git a/Documentation/devicetree/bindings/spi/spi-sun6i.txt b/Documentation/devicetree/bindings/spi/spi-sun6i.txt
new file mode 100644
index 0000000..21de73d
--- /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 at 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>;
+};
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 5072b71..24f3b85 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -446,6 +446,12 @@ 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
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 95af48d..13b6ccf 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_SPI_SH_HSPI) += spi-sh-hspi.o
obj-$(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
diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
new file mode 100644
index 0000000..1747892
--- /dev/null
+++ b/drivers/spi/spi-sun6i.c
@@ -0,0 +1,473 @@
+/*
+ * 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 = devm_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))
+ return PTR_ERR(sspi->base_addr);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "No spi IRQ specified\n");
+ return -ENXIO;
+ }
+
+ ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
+ 0, "sun6i-spi", sspi);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot request IRQ\n");
+ return ret;
+ }
+
+ sspi->master = master;
+ master->bus_num = -1;
+ 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");
+ return PTR_ERR(sspi->hclk);
+ }
+
+ sspi->mclk = devm_clk_get(&pdev->dev, "mod");
+ if (IS_ERR(sspi->mclk)) {
+ dev_err(&pdev->dev, "Unable to acquire module clock\n");
+ return PTR_ERR(sspi->mclk);
+ }
+
+ 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");
+ return PTR_ERR(sspi->rstc);
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ if (!pm_runtime_enabled(&pdev->dev)) {
+ ret = sun6i_spi_runtime_resume(&pdev->dev);
+ if (ret) {
+ dev_err(&pdev->dev, "Couldn't resume the device\n");
+ return ret;
+ }
+ }
+
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (ret) {
+ dev_err(&pdev->dev, "cannot register SPI master\n");
+ goto err;
+ }
+
+ return 0;
+
+err:
+ if (!pm_runtime_enabled(&pdev->dev))
+ sun6i_spi_runtime_suspend(&pdev->dev);
+
+ pm_runtime_disable(&pdev->dev);
+ 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");
--
1.8.4.2
next prev parent reply other threads:[~2014-01-31 11:00 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-31 10:55 [PATCH v3 0/5] Add Allwinner A31 SPI controller support Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` [PATCH v3 1/5] clk: sunxi: Add support for PLL6 on the A31 Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` [PATCH v3 2/5] ARM: sun6i: dt: Add PLL6 and SPI module clocks Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard [this message]
2014-01-31 10:55 ` [PATCH v3 3/5] spi: sunxi: Add Allwinner A31 SPI controller driver Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 12:48 ` Mark Brown
2014-01-31 12:48 ` Mark Brown
2014-01-31 12:48 ` Mark Brown
2014-01-31 22:47 ` Maxime Ripard
2014-01-31 22:47 ` Maxime Ripard
2014-01-31 22:47 ` Maxime Ripard
2014-02-04 0:21 ` Mark Brown
2014-02-04 0:21 ` Mark Brown
2014-02-04 0:21 ` Mark Brown
2014-02-04 9:09 ` Maxime Ripard
2014-02-04 9:09 ` Maxime Ripard
2014-02-04 9:09 ` Maxime Ripard
2014-02-04 11:02 ` Mark Brown
2014-02-04 11:02 ` Mark Brown
2014-02-04 11:02 ` Mark Brown
2014-01-31 10:55 ` [PATCH v3 4/5] ARM: sun6i: dt: Add SPI controllers to the A31 DTSI Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` [PATCH v3 5/5] ARM: sunxi: Enable A31 SPI and SID in the defconfig Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
2014-01-31 10:55 ` Maxime Ripard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1391165752-1819-4-git-send-email-maxime.ripard@free-electrons.com \
--to=maxime.ripard@free-electrons.com \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=emilio@elopez.com.ar \
--cc=kevin.z.m.zh@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=linux-sunxi@googlegroups.com \
--cc=mturquette@linaro.org \
--cc=shuge@allwinnertech.com \
--cc=sunny@allwinnertech.com \
--cc=zhuzhenhua@allwinnertech.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.