--- /dev/null
+From 1ae7667375308c27023d793372d6be1f3b89f5b5 Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime.ripard@free-electrons.com>
+Date: Sat, 22 Feb 2014 22:35:53 +0100
+Subject: [PATCH] spi: sunxi: Add Allwinner A10 SPI controller driver
+
+The older Allwinner SoCs (A10, A13, A10s and A20) all have the same SPI
+controller.
+
+Unfortunately, this SPI controller, even though quite similar, is significantly
+different from the recently supported A31 SPI controller (different registers
+offset, split/merged registers, etc.). Supporting both controllers in a single
+driver would be unreasonable, hence the addition of a new driver.
+
+Like its more recent counterpart, it supports DMA, but the driver only does PIO
+until we have a dmaengine driver for this platform.
+
+Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
+---
+ .../devicetree/bindings/spi/spi-sun4i.txt | 24 ++
+ drivers/spi/Kconfig | 6 +
+ drivers/spi/Makefile | 1 +
+ drivers/spi/spi-sun4i.c | 477 +++++++++++++++++++++
+ 4 files changed, 508 insertions(+)
+ create mode 100644 Documentation/devicetree/bindings/spi/spi-sun4i.txt
+ create mode 100644 drivers/spi/spi-sun4i.c
+
+diff --git a/Documentation/devicetree/bindings/spi/spi-sun4i.txt b/Documentation/devicetree/bindings/spi/spi-sun4i.txt
+new file mode 100644
+index 0000000..de827f5
+--- /dev/null
++++ b/Documentation/devicetree/bindings/spi/spi-sun4i.txt
+@@ -0,0 +1,24 @@
++Allwinner A10 SPI controller
++
++Required properties:
++- compatible: Should be "allwinner,sun4-a10-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
++
++Example:
++
++spi1: spi@01c06000 {
++ compatible = "allwinner,sun4i-a10-spi";
++ reg = <0x01c06000 0x1000>;
++ interrupts = <11>;
++ clocks = <&ahb_gates 21>, <&spi1_clk>;
++ clock-names = "ahb", "mod";
++ status = "disabled";
++ #address-cells = <1>;
++ #size-cells = <0>;
++};
+diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
+index 58530d3..78adfae 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_SUN4I
++ tristate "Allwinner A10 SoCs SPI controller"
++ depends on ARCH_SUNXI || COMPILE_TEST
++ help
++ SPI driver for Allwinner sun4i, sun5i and sun7i SoCs
++
+ config SPI_SUN6I
+ tristate "Allwinner A31 SPI controller"
+ depends on ARCH_SUNXI || COMPILE_TEST
+diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
+index 13b6ccf9..65f4993 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-$(CONFIG_SPI_SUN4I) += spi-sun4i.o
+ obj-$(CONFIG_SPI_SUN6I) += spi-sun6i.o
+ obj-$(CONFIG_SPI_TEGRA114) += spi-tegra114.o
+ obj-$(CONFIG_SPI_TEGRA20_SFLASH) += spi-tegra20-sflash.o
+diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c
+new file mode 100644
+index 0000000..3f82705
+--- /dev/null
++++ b/drivers/spi/spi-sun4i.c
+@@ -0,0 +1,477 @@
++/*
++ * 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/workqueue.h>
++
++#include <linux/spi/spi.h>
++
++#define SUN4I_FIFO_DEPTH 64
++
++#define SUN4I_RXDATA_REG 0x00
++
++#define SUN4I_TXDATA_REG 0x04
++
++#define SUN4I_CTL_REG 0x08
++#define SUN4I_CTL_ENABLE BIT(0)
++#define SUN4I_CTL_MASTER BIT(1)
++#define SUN4I_CTL_CPHA BIT(2)
++#define SUN4I_CTL_CPOL BIT(3)
++#define SUN4I_CTL_CS_ACTIVE_LOW BIT(4)
++#define SUN4I_CTL_LMTF BIT(6)
++#define SUN4I_CTL_TF_RST BIT(8)
++#define SUN4I_CTL_RF_RST BIT(9)
++#define SUN4I_CTL_XCH BIT(10)
++#define SUN4I_CTL_CS_MASK 0x3000
++#define SUN4I_CTL_CS(cs) (((cs) << 12) & SUN4I_CTL_CS_MASK)
++#define SUN4I_CTL_DHB BIT(15)
++#define SUN4I_CTL_CS_MANUAL BIT(16)
++#define SUN4I_CTL_CS_LEVEL BIT(17)
++#define SUN4I_CTL_TP BIT(18)
++
++#define SUN4I_INT_CTL_REG 0x0c
++#define SUN4I_INT_CTL_TC BIT(16)
++
++#define SUN4I_INT_STA_REG 0x10
++
++#define SUN4I_DMA_CTL_REG 0x14
++
++#define SUN4I_WAIT_REG 0x18
++
++#define SUN4I_CLK_CTL_REG 0x1c
++#define SUN4I_CLK_CTL_CDR2_MASK 0xff
++#define SUN4I_CLK_CTL_CDR2(div) ((div) & SUN4I_CLK_CTL_CDR2_MASK)
++#define SUN4I_CLK_CTL_CDR1_MASK 0xf
++#define SUN4I_CLK_CTL_CDR1(div) (((div) & SUN4I_CLK_CTL_CDR1_MASK) << 8)
++#define SUN4I_CLK_CTL_DRS BIT(12)
++
++#define SUN4I_BURST_CNT_REG 0x20
++#define SUN4I_BURST_CNT(cnt) ((cnt) & 0xffffff)
++
++#define SUN4I_XMIT_CNT_REG 0x24
++#define SUN4I_XMIT_CNT(cnt) ((cnt) & 0xffffff)
++
++#define SUN4I_FIFO_STA_REG 0x28
++#define SUN4I_FIFO_STA_RF_CNT_MASK 0x7f
++#define SUN4I_FIFO_STA_RF_CNT_BITS 0
++#define SUN4I_FIFO_STA_TF_CNT_MASK 0x7f
++#define SUN4I_FIFO_STA_TF_CNT_BITS 16
++
++struct sun4i_spi {
++ struct spi_master *master;
++ void __iomem *base_addr;
++ struct clk *hclk;
++ struct clk *mclk;
++
++ struct completion done;
++
++ const u8 *tx_buf;
++ u8 *rx_buf;
++ int len;
++};
++
++static inline u32 sun4i_spi_read(struct sun4i_spi *sspi, u32 reg)
++{
++ return readl(sspi->base_addr + reg);
++}
++
++static inline void sun4i_spi_write(struct sun4i_spi *sspi, u32 reg, u32 value)
++{
++ writel(value, sspi->base_addr + reg);
++}
++
++static inline void sun4i_spi_drain_fifo(struct sun4i_spi *sspi, int len)
++{
++ u32 reg, cnt;
++ u8 byte;
++
++ /* See how much data is available */
++ reg = sun4i_spi_read(sspi, SUN4I_FIFO_STA_REG);
++ reg &= SUN4I_FIFO_STA_RF_CNT_MASK;
++ cnt = reg >> SUN4I_FIFO_STA_RF_CNT_BITS;
++
++ if (len > cnt)
++ len = cnt;
++
++ while (len--) {
++ byte = readb(sspi->base_addr + SUN4I_RXDATA_REG);
++ if (sspi->rx_buf)
++ *sspi->rx_buf++ = byte;
++ }
++}
++
++static inline void sun4i_spi_fill_fifo(struct sun4i_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 + SUN4I_TXDATA_REG);
++ sspi->len--;
++ }
++}
++
++static void sun4i_spi_set_cs(struct spi_device *spi, bool enable)
++{
++ struct sun4i_spi *sspi = spi_master_get_devdata(spi->master);
++ u32 reg;
++
++ reg = sun4i_spi_read(sspi, SUN4I_CTL_REG);
++
++ reg &= ~SUN4I_CTL_CS_MASK;
++ reg |= SUN4I_CTL_CS(spi->chip_select);
++
++ if (enable)
++ reg |= SUN4I_CTL_CS_LEVEL;
++ else
++ reg &= ~SUN4I_CTL_CS_LEVEL;
++
++ /*
++ * Even though this looks irrelevant since we are supposed to
++ * be controlling the chip select manually, this bit also
++ * controls the levels of the chip select for inactive
++ * devices.
++ *
++ * If we don't set it, the chip select level will go low by
++ * default when the device is idle, which is not really
++ * expected in the common case where the chip select is active
++ * low.
++ */
++ if (spi->mode & SPI_CS_HIGH)
++ reg &= ~SUN4I_CTL_CS_ACTIVE_LOW;
++ else
++ reg |= SUN4I_CTL_CS_ACTIVE_LOW;
++
++ sun4i_spi_write(sspi, SUN4I_CTL_REG, reg);
++}
++
++static int sun4i_spi_transfer_one(struct spi_master *master,
++ struct spi_device *spi,
++ struct spi_transfer *tfr)
++{
++ struct sun4i_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 > SUN4I_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 */
++ sun4i_spi_write(sspi, SUN4I_INT_STA_REG, ~0);
++
++
++ reg = sun4i_spi_read(sspi, SUN4I_CTL_REG);
++
++ /* Reset FIFOs */
++ sun4i_spi_write(sspi, SUN4I_CTL_REG,
++ reg | SUN4I_CTL_RF_RST | SUN4I_CTL_TF_RST);
++
++ /*
++ * Setup the transfer control register: Chip Select,
++ * polarities, etc.
++ */
++ if (spi->mode & SPI_CPOL)
++ reg |= SUN4I_CTL_CPOL;
++ else
++ reg &= ~SUN4I_CTL_CPOL;
++
++ if (spi->mode & SPI_CPHA)
++ reg |= SUN4I_CTL_CPHA;
++ else
++ reg &= ~SUN4I_CTL_CPHA;
++
++ if (spi->mode & SPI_LSB_FIRST)
++ reg |= SUN4I_CTL_LMTF;
++ else
++ reg &= ~SUN4I_CTL_LMTF;
++
++
++ /*
++ * If it's a TX only transfer, we don't want to fill the RX
++ * FIFO with bogus data
++ */
++ if (sspi->rx_buf)
++ reg &= ~SUN4I_CTL_DHB;
++ else
++ reg |= SUN4I_CTL_DHB;
++
++ /* We want to control the chip select manually */
++ reg |= SUN4I_CTL_CS_MANUAL;
++
++ sun4i_spi_write(sspi, SUN4I_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 + 1))
++ * 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 <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) {
++ if (div > 0)
++ div--;
++
++ reg = SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS;
++ } else {
++ div = ilog2(mclk_rate) - ilog2(spi->max_speed_hz);
++ reg = SUN4I_CLK_CTL_CDR1(div);
++ }
++
++ sun4i_spi_write(sspi, SUN4I_CLK_CTL_REG, reg);
++
++ /* Setup the transfer now... */
++ if (sspi->tx_buf)
++ tx_len = tfr->len;
++
++ /* Setup the counters */
++ sun4i_spi_write(sspi, SUN4I_BURST_CNT_REG, SUN4I_BURST_CNT(tfr->len));
++ sun4i_spi_write(sspi, SUN4I_XMIT_CNT_REG, SUN4I_XMIT_CNT(tx_len));
++
++ /* Fill the TX FIFO */
++ sun4i_spi_fill_fifo(sspi, SUN4I_FIFO_DEPTH);
++
++ /* Enable the interrupts */
++ sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, SUN4I_INT_CTL_TC);
++
++ /* Start the transfer */
++ reg = sun4i_spi_read(sspi, SUN4I_CTL_REG);
++ sun4i_spi_write(sspi, SUN4I_CTL_REG, reg | SUN4I_CTL_XCH);
++
++ timeout = wait_for_completion_timeout(&sspi->done,
++ msecs_to_jiffies(1000));
++ if (!timeout) {
++ ret = -ETIMEDOUT;
++ goto out;
++ }
++
++ sun4i_spi_drain_fifo(sspi, SUN4I_FIFO_DEPTH);
++
++out:
++ sun4i_spi_write(sspi, SUN4I_INT_CTL_REG, 0);
++
++ return ret;
++}
++
++static irqreturn_t sun4i_spi_handler(int irq, void *dev_id)
++{
++ struct sun4i_spi *sspi = dev_id;
++ u32 status = sun4i_spi_read(sspi, SUN4I_INT_STA_REG);
++
++ /* Transfer complete */
++ if (status & SUN4I_INT_CTL_TC) {
++ sun4i_spi_write(sspi, SUN4I_INT_STA_REG, SUN4I_INT_CTL_TC);
++ complete(&sspi->done);
++ return IRQ_HANDLED;
++ }
++
++ return IRQ_NONE;
++}
++
++static int sun4i_spi_runtime_resume(struct device *dev)
++{
++ struct spi_master *master = dev_get_drvdata(dev);
++ struct sun4i_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;
++ }
++
++ sun4i_spi_write(sspi, SUN4I_CTL_REG,
++ SUN4I_CTL_ENABLE | SUN4I_CTL_MASTER | SUN4I_CTL_TP);
++
++ return 0;
++
++err:
++ clk_disable_unprepare(sspi->hclk);
++out:
++ return ret;
++}
++
++static int sun4i_spi_runtime_suspend(struct device *dev)
++{
++ struct spi_master *master = dev_get_drvdata(dev);
++ struct sun4i_spi *sspi = spi_master_get_devdata(master);
++
++ clk_disable_unprepare(sspi->mclk);
++ clk_disable_unprepare(sspi->hclk);
++
++ return 0;
++}
++
++static int sun4i_spi_probe(struct platform_device *pdev)
++{
++ struct spi_master *master;
++ struct sun4i_spi *sspi;
++ struct resource *res;
++ int ret = 0, irq;
++
++ master = spi_alloc_master(&pdev->dev, sizeof(struct sun4i_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, sun4i_spi_handler,
++ 0, "sun4i-spi", sspi);
++ if (ret) {
++ dev_err(&pdev->dev, "Cannot request IRQ\n");
++ goto err_free_master;
++ }
++
++ sspi->master = master;
++ master->set_cs = sun4i_spi_set_cs;
++ master->transfer_one = sun4i_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);
++
++ /*
++ * This wake-up/shutdown pattern is to be able to have the
++ * device woken up, even if runtime_pm is disabled
++ */
++ ret = sun4i_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);
++ sun4i_spi_runtime_suspend(&pdev->dev);
++err_free_master:
++ spi_master_put(master);
++ return ret;
++}
++
++static int sun4i_spi_remove(struct platform_device *pdev)
++{
++ pm_runtime_disable(&pdev->dev);
++
++ return 0;
++}
++
++static const struct of_device_id sun4i_spi_match[] = {
++ { .compatible = "allwinner,sun4i-a10-spi", },
++ {}
++};
++MODULE_DEVICE_TABLE(of, sun4i_spi_match);
++
++static const struct dev_pm_ops sun4i_spi_pm_ops = {
++ .runtime_resume = sun4i_spi_runtime_resume,
++ .runtime_suspend = sun4i_spi_runtime_suspend,
++};
++
++static struct platform_driver sun4i_spi_driver = {
++ .probe = sun4i_spi_probe,
++ .remove = sun4i_spi_remove,
++ .driver = {
++ .name = "sun4i-spi",
++ .owner = THIS_MODULE,
++ .of_match_table = sun4i_spi_match,
++ .pm = &sun4i_spi_pm_ops,
++ },
++};
++module_platform_driver(sun4i_spi_driver);
++
++MODULE_AUTHOR("Pan Nan <pannan@allwinnertech.com>");
++MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
++MODULE_DESCRIPTION("Allwinner A1X/A20 SPI controller driver");
++MODULE_LICENSE("GPL");
+--
+2.0.3
+
projects / openwrt / openwrt.git / blobdiff