+++ /dev/null
-From fc006d0622ab8c43086b2c9018c03012db332033 Mon Sep 17 00:00:00 2001
-From: John Crispin <blogic@openwrt.org>
-Date: Sun, 27 Jul 2014 11:15:12 +0100
-Subject: [PATCH 50/57] SPI: ralink: add Ralink SoC spi driver
-
-Add the driver needed to make SPI work on Ralink SoC.
-
-Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
-Acked-by: John Crispin <blogic@openwrt.org>
----
- drivers/spi/Kconfig | 6 +
- drivers/spi/Makefile | 1 +
- drivers/spi/spi-rt2880.c | 432 ++++++++++++++++++++++++++++++++++++++++++++++
- 3 files changed, 439 insertions(+)
- create mode 100644 drivers/spi/spi-rt2880.c
-
---- a/drivers/spi/Kconfig
-+++ b/drivers/spi/Kconfig
-@@ -390,6 +390,12 @@ config SPI_RSPI
- help
- SPI driver for Renesas RSPI and QSPI blocks.
-
-+config SPI_RT2880
-+ tristate "Ralink RT288x SPI Controller"
-+ depends on RALINK
-+ help
-+ This selects a driver for the Ralink RT288x/RT305x SPI Controller.
-+
- config SPI_S3C24XX
- tristate "Samsung S3C24XX series SPI"
- depends on ARCH_S3C24XX
---- a/drivers/spi/Makefile
-+++ b/drivers/spi/Makefile
-@@ -61,6 +61,7 @@ spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_
- obj-$(CONFIG_SPI_PXA2XX) += spi-pxa2xx-platform.o
- obj-$(CONFIG_SPI_PXA2XX_PCI) += spi-pxa2xx-pci.o
- obj-$(CONFIG_SPI_RSPI) += spi-rspi.o
-+obj-$(CONFIG_SPI_RT2880) += spi-rt2880.o
- obj-$(CONFIG_SPI_S3C24XX) += spi-s3c24xx-hw.o
- spi-s3c24xx-hw-y := spi-s3c24xx.o
- spi-s3c24xx-hw-$(CONFIG_SPI_S3C24XX_FIQ) += spi-s3c24xx-fiq.o
---- /dev/null
-+++ b/drivers/spi/spi-rt2880.c
-@@ -0,0 +1,432 @@
-+/*
-+ * spi-rt2880.c -- Ralink RT288x/RT305x SPI controller driver
-+ *
-+ * Copyright (C) 2011 Sergiy <piratfm@gmail.com>
-+ * Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
-+ *
-+ * Some parts are based on spi-orion.c:
-+ * Author: Shadi Ammouri <shadi@marvell.com>
-+ * Copyright (C) 2007-2008 Marvell Ltd.
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+
-+#include <linux/init.h>
-+#include <linux/module.h>
-+#include <linux/clk.h>
-+#include <linux/err.h>
-+#include <linux/delay.h>
-+#include <linux/io.h>
-+#include <linux/reset.h>
-+#include <linux/spi/spi.h>
-+#include <linux/platform_device.h>
-+
-+#define DRIVER_NAME "spi-rt2880"
-+/* only one slave is supported*/
-+#define RALINK_NUM_CHIPSELECTS 1
-+/* in usec */
-+#define RALINK_SPI_WAIT_MAX_LOOP 2000
-+
-+#define RAMIPS_SPI_STAT 0x00
-+#define RAMIPS_SPI_CFG 0x10
-+#define RAMIPS_SPI_CTL 0x14
-+#define RAMIPS_SPI_DATA 0x20
-+#define RAMIPS_SPI_FIFO_STAT 0x38
-+
-+/* SPISTAT register bit field */
-+#define SPISTAT_BUSY BIT(0)
-+
-+/* SPICFG register bit field */
-+#define SPICFG_LSBFIRST 0
-+#define SPICFG_MSBFIRST BIT(8)
-+#define SPICFG_SPICLKPOL BIT(6)
-+#define SPICFG_RXCLKEDGE_FALLING BIT(5)
-+#define SPICFG_TXCLKEDGE_FALLING BIT(4)
-+#define SPICFG_SPICLK_PRESCALE_MASK 0x7
-+#define SPICFG_SPICLK_DIV2 0
-+#define SPICFG_SPICLK_DIV4 1
-+#define SPICFG_SPICLK_DIV8 2
-+#define SPICFG_SPICLK_DIV16 3
-+#define SPICFG_SPICLK_DIV32 4
-+#define SPICFG_SPICLK_DIV64 5
-+#define SPICFG_SPICLK_DIV128 6
-+#define SPICFG_SPICLK_DISABLE 7
-+
-+/* SPICTL register bit field */
-+#define SPICTL_HIZSDO BIT(3)
-+#define SPICTL_STARTWR BIT(2)
-+#define SPICTL_STARTRD BIT(1)
-+#define SPICTL_SPIENA BIT(0)
-+
-+/* SPIFIFOSTAT register bit field */
-+#define SPIFIFOSTAT_TXFULL BIT(17)
-+
-+struct rt2880_spi {
-+ struct spi_master *master;
-+ void __iomem *base;
-+ unsigned int sys_freq;
-+ unsigned int speed;
-+ struct clk *clk;
-+ spinlock_t lock;
-+};
-+
-+static inline struct rt2880_spi *spidev_to_rt2880_spi(struct spi_device *spi)
-+{
-+ return spi_master_get_devdata(spi->master);
-+}
-+
-+static inline u32 rt2880_spi_read(struct rt2880_spi *rs, u32 reg)
-+{
-+ return ioread32(rs->base + reg);
-+}
-+
-+static inline void rt2880_spi_write(struct rt2880_spi *rs, u32 reg, u32 val)
-+{
-+ iowrite32(val, rs->base + reg);
-+}
-+
-+static inline void rt2880_spi_setbits(struct rt2880_spi *rs, u32 reg, u32 mask)
-+{
-+ void __iomem *addr = rs->base + reg;
-+ unsigned long flags;
-+ u32 val;
-+
-+ spin_lock_irqsave(&rs->lock, flags);
-+ val = ioread32(addr);
-+ val |= mask;
-+ iowrite32(val, addr);
-+ spin_unlock_irqrestore(&rs->lock, flags);
-+}
-+
-+static inline void rt2880_spi_clrbits(struct rt2880_spi *rs, u32 reg, u32 mask)
-+{
-+ void __iomem *addr = rs->base + reg;
-+ unsigned long flags;
-+ u32 val;
-+
-+ spin_lock_irqsave(&rs->lock, flags);
-+ val = ioread32(addr);
-+ val &= ~mask;
-+ iowrite32(val, addr);
-+ spin_unlock_irqrestore(&rs->lock, flags);
-+}
-+
-+static int rt2880_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
-+{
-+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
-+ u32 rate;
-+ u32 prescale;
-+ u32 reg;
-+
-+ dev_dbg(&spi->dev, "speed:%u\n", speed);
-+
-+ /*
-+ * the supported rates are: 2, 4, 8, ... 128
-+ * round up as we look for equal or less speed
-+ */
-+ rate = DIV_ROUND_UP(rs->sys_freq, speed);
-+ dev_dbg(&spi->dev, "rate-1:%u\n", rate);
-+ rate = roundup_pow_of_two(rate);
-+ dev_dbg(&spi->dev, "rate-2:%u\n", rate);
-+
-+ /* check if requested speed is too small */
-+ if (rate > 128)
-+ return -EINVAL;
-+
-+ if (rate < 2)
-+ rate = 2;
-+
-+ /* Convert the rate to SPI clock divisor value. */
-+ prescale = ilog2(rate / 2);
-+ dev_dbg(&spi->dev, "prescale:%u\n", prescale);
-+
-+ reg = rt2880_spi_read(rs, RAMIPS_SPI_CFG);
-+ reg = ((reg & ~SPICFG_SPICLK_PRESCALE_MASK) | prescale);
-+ rt2880_spi_write(rs, RAMIPS_SPI_CFG, reg);
-+ rs->speed = speed;
-+ return 0;
-+}
-+
-+/*
-+ * called only when no transfer is active on the bus
-+ */
-+static int
-+rt2880_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
-+{
-+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
-+ unsigned int speed = spi->max_speed_hz;
-+ int rc;
-+
-+ if ((t != NULL) && t->speed_hz)
-+ speed = t->speed_hz;
-+
-+ if (rs->speed != speed) {
-+ dev_dbg(&spi->dev, "speed_hz:%u\n", speed);
-+ rc = rt2880_spi_baudrate_set(spi, speed);
-+ if (rc)
-+ return rc;
-+ }
-+
-+ return 0;
-+}
-+
-+static void rt2880_spi_set_cs(struct rt2880_spi *rs, int enable)
-+{
-+ if (enable)
-+ rt2880_spi_clrbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
-+ else
-+ rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
-+}
-+
-+static inline int rt2880_spi_wait_till_ready(struct rt2880_spi *rs)
-+{
-+ int i;
-+
-+ for (i = 0; i < RALINK_SPI_WAIT_MAX_LOOP; i++) {
-+ u32 status;
-+
-+ status = rt2880_spi_read(rs, RAMIPS_SPI_STAT);
-+ if ((status & SPISTAT_BUSY) == 0)
-+ return 0;
-+
-+ cpu_relax();
-+ udelay(1);
-+ }
-+
-+ return -ETIMEDOUT;
-+}
-+
-+static unsigned int
-+rt2880_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
-+{
-+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
-+ unsigned count = 0;
-+ u8 *rx = xfer->rx_buf;
-+ const u8 *tx = xfer->tx_buf;
-+ int err;
-+
-+ dev_dbg(&spi->dev, "read (%d): %s %s\n", xfer->len,
-+ (tx != NULL) ? "tx" : " ",
-+ (rx != NULL) ? "rx" : " ");
-+
-+ if (tx) {
-+ for (count = 0; count < xfer->len; count++) {
-+ rt2880_spi_write(rs, RAMIPS_SPI_DATA, tx[count]);
-+ rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTWR);
-+ err = rt2880_spi_wait_till_ready(rs);
-+ if (err) {
-+ dev_err(&spi->dev, "TX failed, err=%d\n", err);
-+ goto out;
-+ }
-+ }
-+ }
-+
-+ if (rx) {
-+ for (count = 0; count < xfer->len; count++) {
-+ rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTRD);
-+ err = rt2880_spi_wait_till_ready(rs);
-+ if (err) {
-+ dev_err(&spi->dev, "RX failed, err=%d\n", err);
-+ goto out;
-+ }
-+ rx[count] = (u8) rt2880_spi_read(rs, RAMIPS_SPI_DATA);
-+ }
-+ }
-+
-+out:
-+ return count;
-+}
-+
-+static int rt2880_spi_transfer_one_message(struct spi_master *master,
-+ struct spi_message *m)
-+{
-+ struct rt2880_spi *rs = spi_master_get_devdata(master);
-+ struct spi_device *spi = m->spi;
-+ struct spi_transfer *t = NULL;
-+ int par_override = 0;
-+ int status = 0;
-+ int cs_active = 0;
-+
-+ /* Load defaults */
-+ status = rt2880_spi_setup_transfer(spi, NULL);
-+ if (status < 0)
-+ goto msg_done;
-+
-+ list_for_each_entry(t, &m->transfers, transfer_list) {
-+ if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
-+ dev_err(&spi->dev,
-+ "message rejected: invalid transfer data buffers\n");
-+ status = -EIO;
-+ goto msg_done;
-+ }
-+
-+ if (t->speed_hz && t->speed_hz < (rs->sys_freq / 128)) {
-+ dev_err(&spi->dev,
-+ "message rejected: device min speed (%d Hz) exceeds required transfer speed (%d Hz)\n",
-+ (rs->sys_freq / 128), t->speed_hz);
-+ status = -EIO;
-+ goto msg_done;
-+ }
-+
-+ if (par_override || t->speed_hz || t->bits_per_word) {
-+ par_override = 1;
-+ status = rt2880_spi_setup_transfer(spi, t);
-+ if (status < 0)
-+ goto msg_done;
-+ if (!t->speed_hz && !t->bits_per_word)
-+ par_override = 0;
-+ }
-+
-+ if (!cs_active) {
-+ rt2880_spi_set_cs(rs, 1);
-+ cs_active = 1;
-+ }
-+
-+ if (t->len)
-+ m->actual_length += rt2880_spi_write_read(spi, t);
-+
-+ if (t->delay_usecs)
-+ udelay(t->delay_usecs);
-+
-+ if (t->cs_change) {
-+ rt2880_spi_set_cs(rs, 0);
-+ cs_active = 0;
-+ }
-+ }
-+
-+msg_done:
-+ if (cs_active)
-+ rt2880_spi_set_cs(rs, 0);
-+
-+ m->status = status;
-+ spi_finalize_current_message(master);
-+
-+ return 0;
-+}
-+
-+static int rt2880_spi_setup(struct spi_device *spi)
-+{
-+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
-+
-+ if ((spi->max_speed_hz == 0) ||
-+ (spi->max_speed_hz > (rs->sys_freq / 2)))
-+ spi->max_speed_hz = (rs->sys_freq / 2);
-+
-+ if (spi->max_speed_hz < (rs->sys_freq / 128)) {
-+ dev_err(&spi->dev, "setup: requested speed is too low %d Hz\n",
-+ spi->max_speed_hz);
-+ return -EINVAL;
-+ }
-+
-+ /*
-+ * baudrate & width will be set rt2880_spi_setup_transfer
-+ */
-+ return 0;
-+}
-+
-+static void rt2880_spi_reset(struct rt2880_spi *rs)
-+{
-+ rt2880_spi_write(rs, RAMIPS_SPI_CFG,
-+ SPICFG_MSBFIRST | SPICFG_TXCLKEDGE_FALLING |
-+ SPICFG_SPICLK_DIV16 | SPICFG_SPICLKPOL);
-+ rt2880_spi_write(rs, RAMIPS_SPI_CTL, SPICTL_HIZSDO | SPICTL_SPIENA);
-+}
-+
-+static int rt2880_spi_probe(struct platform_device *pdev)
-+{
-+ struct spi_master *master;
-+ struct rt2880_spi *rs;
-+ unsigned long flags;
-+ void __iomem *base;
-+ struct resource *r;
-+ int status = 0;
-+ struct clk *clk;
-+
-+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-+ base = devm_ioremap_resource(&pdev->dev, r);
-+ if (IS_ERR(base))
-+ return PTR_ERR(base);
-+
-+ clk = devm_clk_get(&pdev->dev, NULL);
-+ if (IS_ERR(clk)) {
-+ dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
-+ status);
-+ return PTR_ERR(clk);
-+ }
-+
-+ status = clk_prepare_enable(clk);
-+ if (status)
-+ return status;
-+
-+ master = spi_alloc_master(&pdev->dev, sizeof(*rs));
-+ if (master == NULL) {
-+ dev_dbg(&pdev->dev, "master allocation failed\n");
-+ return -ENOMEM;
-+ }
-+
-+ /* we support only mode 0, and no options */
-+ master->mode_bits = 0;
-+
-+ master->setup = rt2880_spi_setup;
-+ master->transfer_one_message = rt2880_spi_transfer_one_message;
-+ master->num_chipselect = RALINK_NUM_CHIPSELECTS;
-+ master->bits_per_word_mask = SPI_BPW_MASK(8);
-+ master->dev.of_node = pdev->dev.of_node;
-+
-+ dev_set_drvdata(&pdev->dev, master);
-+
-+ rs = spi_master_get_devdata(master);
-+ rs->base = base;
-+ rs->clk = clk;
-+ rs->master = master;
-+ rs->sys_freq = clk_get_rate(rs->clk);
-+ dev_dbg(&pdev->dev, "sys_freq: %u\n", rs->sys_freq);
-+ spin_lock_irqsave(&rs->lock, flags);
-+
-+ device_reset(&pdev->dev);
-+
-+ rt2880_spi_reset(rs);
-+
-+ return spi_register_master(master);
-+}
-+
-+static int rt2880_spi_remove(struct platform_device *pdev)
-+{
-+ struct spi_master *master;
-+ struct rt2880_spi *rs;
-+
-+ master = dev_get_drvdata(&pdev->dev);
-+ rs = spi_master_get_devdata(master);
-+
-+ clk_disable(rs->clk);
-+ spi_unregister_master(master);
-+
-+ return 0;
-+}
-+
-+MODULE_ALIAS("platform:" DRIVER_NAME);
-+
-+static const struct of_device_id rt2880_spi_match[] = {
-+ { .compatible = "ralink,rt2880-spi" },
-+ {},
-+};
-+MODULE_DEVICE_TABLE(of, rt2880_spi_match);
-+
-+static struct platform_driver rt2880_spi_driver = {
-+ .driver = {
-+ .name = DRIVER_NAME,
-+ .owner = THIS_MODULE,
-+ .of_match_table = rt2880_spi_match,
-+ },
-+ .probe = rt2880_spi_probe,
-+ .remove = rt2880_spi_remove,
-+};
-+
-+module_platform_driver(rt2880_spi_driver);
-+
-+MODULE_DESCRIPTION("Ralink SPI driver");
-+MODULE_AUTHOR("Sergiy <piratfm@gmail.com>");
-+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
-+MODULE_LICENSE("GPL");
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