--- /dev/null
+From d345c53b941a3d791c26f900af6e85aa1bcaf8b6 Mon Sep 17 00:00:00 2001
+From: John Crispin <blogic@openwrt.org>
+Date: Mon, 22 Apr 2013 23:16:18 +0200
+Subject: [PATCH 24/33] SPI: ralink: add Ralink SoC spi driver
+
+Add the driver needed to make SPI work on Ralink SoC.
+
+Signed-off-by: John Crispin <blogic@openwrt.org>
+---
+ drivers/spi/Kconfig | 6 +
+ drivers/spi/Makefile | 1 +
+ drivers/spi/spi-ralink.c | 475 ++++++++++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 482 insertions(+)
+ create mode 100644 drivers/spi/spi-ralink.c
+
+diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
+index 92a9345..30e73ea 100644
+--- a/drivers/spi/Kconfig
++++ b/drivers/spi/Kconfig
+@@ -345,6 +345,12 @@ config SPI_RSPI
+ help
+ SPI driver for Renesas RSPI blocks.
+
++config SPI_RALINK
++ tristate "Ralink RT288x/RT305x/RT3662 SPI Controller"
++ depends on (SOC_RT288X || SOC_RT305X || SOC_RT3883 || SOC_MT7620)
++ help
++ This selects a driver for the Ralink RT288x/RT305x SPI Controller.
++
+ config SPI_S3C24XX
+ tristate "Samsung S3C24XX series SPI"
+ depends on ARCH_S3C24XX
+diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
+index 33f9c09..724e8de1 100644
+--- a/drivers/spi/Makefile
++++ b/drivers/spi/Makefile
+@@ -55,6 +55,7 @@ spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_DMA) += spi-pxa2xx-dma.o
+ obj-$(CONFIG_SPI_PXA2XX) += spi-pxa2xx-platform.o
+ obj-$(CONFIG_SPI_PXA2XX_PCI) += spi-pxa2xx-pci.o
+ obj-$(CONFIG_SPI_RSPI) += spi-rspi.o
++obj-$(CONFIG_SPI_RALINK) += spi-ralink.o
+ obj-$(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
+diff --git a/drivers/spi/spi-ralink.c b/drivers/spi/spi-ralink.c
+new file mode 100644
+index 0000000..b07cbaa
+--- /dev/null
++++ b/drivers/spi/spi-ralink.c
+@@ -0,0 +1,475 @@
++/*
++ * spi-ralink.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-ralink"
++#define RALINK_NUM_CHIPSELECTS 1 /* only one slave is supported*/
++#define RALINK_SPI_WAIT_RDY_MAX_LOOP 2000 /* in usec */
++
++#define RAMIPS_SPI_STAT 0x00
++#define RAMIPS_SPI_CFG 0x10
++#define RAMIPS_SPI_CTL 0x14
++#define RAMIPS_SPI_DATA 0x20
++
++/* 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)
++
++#ifdef DEBUG
++#define spi_debug(args...) printk(args)
++#else
++#define spi_debug(args...)
++#endif
++
++struct ralink_spi {
++ struct spi_master *master;
++ void __iomem *base;
++ unsigned int sys_freq;
++ unsigned int speed;
++ struct clk *clk;
++};
++
++static inline struct ralink_spi *spidev_to_ralink_spi(struct spi_device *spi)
++{
++ return spi_master_get_devdata(spi->master);
++}
++
++static inline u32 ralink_spi_read(struct ralink_spi *rs, u32 reg)
++{
++ return ioread32(rs->base + reg);
++}
++
++static inline void ralink_spi_write(struct ralink_spi *rs, u32 reg, u32 val)
++{
++ iowrite32(val, rs->base + reg);
++}
++
++static inline void ralink_spi_setbits(struct ralink_spi *rs, u32 reg, u32 mask)
++{
++ void __iomem *addr = rs->base + reg;
++ u32 val;
++
++ val = ioread32(addr);
++ val |= mask;
++ iowrite32(val, addr);
++}
++
++static inline void ralink_spi_clrbits(struct ralink_spi *rs, u32 reg, u32 mask)
++{
++ void __iomem *addr = rs->base + reg;
++ u32 val;
++
++ val = ioread32(addr);
++ val &= ~mask;
++ iowrite32(val, addr);
++}
++
++static int ralink_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
++{
++ struct ralink_spi *rs = spidev_to_ralink_spi(spi);
++ u32 rate;
++ u32 prescale;
++ u32 reg;
++
++ spi_debug("%s: speed:%u\n", __func__, 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);
++ spi_debug("%s: rate-1:%u\n", __func__, rate);
++ rate = roundup_pow_of_two(rate);
++ spi_debug("%s: rate-2:%u\n", __func__, 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);
++ spi_debug("%s: prescale:%u\n", __func__, prescale);
++
++ reg = ralink_spi_read(rs, RAMIPS_SPI_CFG);
++ reg = ((reg & ~SPICFG_SPICLK_PRESCALE_MASK) | prescale);
++ ralink_spi_write(rs, RAMIPS_SPI_CFG, reg);
++ rs->speed = speed;
++ return 0;
++}
++
++/*
++ * called only when no transfer is active on the bus
++ */
++static int
++ralink_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
++{
++ struct ralink_spi *rs = spidev_to_ralink_spi(spi);
++ unsigned int speed = spi->max_speed_hz;
++ int rc;
++ unsigned int bits_per_word = 8;
++
++ if ((t != NULL) && t->speed_hz)
++ speed = t->speed_hz;
++
++ if ((t != NULL) && t->bits_per_word)
++ bits_per_word = t->bits_per_word;
++
++ if (rs->speed != speed) {
++ spi_debug("%s: speed_hz:%u\n", __func__, speed);
++ rc = ralink_spi_baudrate_set(spi, speed);
++ if (rc)
++ return rc;
++ }
++
++ if (bits_per_word != 8) {
++ spi_debug("%s: bad bits_per_word: %u\n", __func__,
++ bits_per_word);
++ return -EINVAL;
++ }
++
++ return 0;
++}
++
++static void ralink_spi_set_cs(struct ralink_spi *rs, int enable)
++{
++ if (enable)
++ ralink_spi_clrbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
++ else
++ ralink_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
++}
++
++static inline int ralink_spi_wait_till_ready(struct ralink_spi *rs)
++{
++ int i;
++
++ for (i = 0; i < RALINK_SPI_WAIT_RDY_MAX_LOOP; i++) {
++ u32 status;
++
++ status = ralink_spi_read(rs, RAMIPS_SPI_STAT);
++ if ((status & SPISTAT_BUSY) == 0)
++ return 0;
++
++ udelay(1);
++ }
++
++ return -ETIMEDOUT;
++}
++
++static unsigned int
++ralink_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
++{
++ struct ralink_spi *rs = spidev_to_ralink_spi(spi);
++ unsigned count = 0;
++ u8 *rx = xfer->rx_buf;
++ const u8 *tx = xfer->tx_buf;
++ int err;
++
++ spi_debug("%s(%d): %s %s\n", __func__, xfer->len,
++ (tx != NULL) ? "tx" : " ",
++ (rx != NULL) ? "rx" : " ");
++
++ if (tx) {
++ for (count = 0; count < xfer->len; count++) {
++ ralink_spi_write(rs, RAMIPS_SPI_DATA, tx[count]);
++ ralink_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTWR);
++ err = ralink_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++) {
++ ralink_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTRD);
++ err = ralink_spi_wait_till_ready(rs);
++ if (err) {
++ dev_err(&spi->dev, "RX failed, err=%d\n", err);
++ goto out;
++ }
++ rx[count] = (u8) ralink_spi_read(rs, RAMIPS_SPI_DATA);
++ }
++ }
++
++out:
++ return count;
++}
++
++static int ralink_spi_transfer_one_message(struct spi_master *master,
++ struct spi_message *m)
++{
++ struct ralink_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 = ralink_spi_setup_transfer(spi, NULL);
++ if (status < 0)
++ goto msg_done;
++
++ list_for_each_entry(t, &m->transfers, transfer_list) {
++ unsigned int bits_per_word = spi->bits_per_word;
++
++ 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->bits_per_word)
++ bits_per_word = t->bits_per_word;
++
++ if (bits_per_word != 8) {
++ dev_err(&spi->dev,
++ "message rejected: invalid transfer bits_per_word (%d bits)\n",
++ bits_per_word);
++ 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 = ralink_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) {
++ ralink_spi_set_cs(rs, 1);
++ cs_active = 1;
++ }
++
++ if (t->len)
++ m->actual_length += ralink_spi_write_read(spi, t);
++
++ if (t->delay_usecs)
++ udelay(t->delay_usecs);
++
++ if (t->cs_change) {
++ ralink_spi_set_cs(rs, 0);
++ cs_active = 0;
++ }
++ }
++
++msg_done:
++ if (cs_active)
++ ralink_spi_set_cs(rs, 0);
++
++ m->status = status;
++ spi_finalize_current_message(master);
++
++ return 0;
++}
++
++static int ralink_spi_setup(struct spi_device *spi)
++{
++ struct ralink_spi *rs = spidev_to_ralink_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;
++ }
++
++ if (spi->bits_per_word != 0 && spi->bits_per_word != 8) {
++ dev_err(&spi->dev,
++ "setup: requested bits per words - os wrong %d bpw\n",
++ spi->bits_per_word);
++ return -EINVAL;
++ }
++
++ if (spi->bits_per_word == 0)
++ spi->bits_per_word = 8;
++
++ /*
++ * baudrate & width will be set ralink_spi_setup_transfer
++ */
++ return 0;
++}
++
++static void ralink_spi_reset(struct ralink_spi *rs)
++{
++ ralink_spi_write(rs, RAMIPS_SPI_CFG,
++ SPICFG_MSBFIRST | SPICFG_TXCLKEDGE_FALLING |
++ SPICFG_SPICLK_DIV16 | SPICFG_SPICLKPOL);
++ ralink_spi_write(rs, RAMIPS_SPI_CTL, SPICTL_HIZSDO | SPICTL_SPIENA);
++}
++
++static int ralink_spi_probe(struct platform_device *pdev)
++{
++ struct spi_master *master;
++ struct ralink_spi *rs;
++ struct resource *r;
++ int status = 0;
++
++ master = spi_alloc_master(&pdev->dev, sizeof(*rs));
++ if (master == NULL) {
++ dev_dbg(&pdev->dev, "master allocation failed\n");
++ return -ENOMEM;
++ }
++
++ //if (pdev->id != -1)
++ master->bus_num = 0;
++
++ /* we support only mode 0, and no options */
++ master->mode_bits = 0;
++
++ master->setup = ralink_spi_setup;
++ master->transfer_one_message = ralink_spi_transfer_one_message;
++ master->num_chipselect = RALINK_NUM_CHIPSELECTS;
++ master->dev.of_node = pdev->dev.of_node;
++
++ dev_set_drvdata(&pdev->dev, master);
++
++ rs = spi_master_get_devdata(master);
++ rs->master = master;
++
++ rs->clk = clk_get(&pdev->dev, NULL);
++ if (IS_ERR(rs->clk)) {
++ status = PTR_ERR(rs->clk);
++ dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
++ status);
++ goto out_put_master;
++ }
++
++ status = clk_enable(rs->clk);
++ if (status)
++ goto out_put_clk;
++
++ rs->sys_freq = clk_get_rate(rs->clk);
++ spi_debug("%s: sys_freq: %u\n", __func__, rs->sys_freq);
++
++ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++ if (r == NULL) {
++ status = -ENODEV;
++ goto out_disable_clk;
++ }
++
++ rs->base = devm_request_and_ioremap(&pdev->dev, r);
++ if (!rs->base) {
++ status = -EADDRNOTAVAIL;
++ goto out_disable_clk;
++ }
++
++ device_reset(&pdev->dev);
++
++ ralink_spi_reset(rs);
++
++ status = spi_register_master(master);
++ if (status)
++ goto out_disable_clk;
++
++ return 0;
++
++out_disable_clk:
++ clk_disable(rs->clk);
++out_put_clk:
++ clk_put(rs->clk);
++out_put_master:
++ spi_master_put(master);
++ return status;
++}
++
++static int ralink_spi_remove(struct platform_device *pdev)
++{
++ struct spi_master *master;
++ struct ralink_spi *rs;
++
++ master = dev_get_drvdata(&pdev->dev);
++ rs = spi_master_get_devdata(master);
++
++ clk_disable(rs->clk);
++ clk_put(rs->clk);
++ spi_unregister_master(master);
++
++ return 0;
++}
++
++MODULE_ALIAS("platform:" DRIVER_NAME);
++
++static const struct of_device_id ralink_spi_match[] = {
++ { .compatible = "ralink,rt2880-spi" },
++ {},
++};
++MODULE_DEVICE_TABLE(of, ralink_spi_match);
++
++static struct platform_driver ralink_spi_driver = {
++ .driver = {
++ .name = DRIVER_NAME,
++ .owner = THIS_MODULE,
++ .of_match_table = ralink_spi_match,
++ },
++ .probe = ralink_spi_probe,
++ .remove = ralink_spi_remove,
++};
++
++module_platform_driver(ralink_spi_driver);
++
++MODULE_DESCRIPTION("Ralink SPI driver");
++MODULE_AUTHOR("Sergiy <piratfm@gmail.com>");
++MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
++MODULE_LICENSE("GPL");
+--
+1.7.10.4
+
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