From 683af4ebb91a1600df1946ac4769d916b8a1be65 Mon Sep 17 00:00:00 2001 From: John Crispin Date: Sun, 27 Jul 2014 11:15:12 +0100 Subject: [PATCH 42/53] SPI: ralink: add Ralink SoC spi driver Add the driver needed to make SPI work on Ralink SoC. Signed-off-by: Gabor Juhos Acked-by: John Crispin --- drivers/spi/Kconfig | 6 + drivers/spi/Makefile | 1 + drivers/spi/spi-rt2880.c | 530 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 537 insertions(+) create mode 100644 drivers/spi/spi-rt2880.c --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -823,6 +823,12 @@ config SPI_QCOM_GENI This driver can also be built as a module. If so, the module will be called spi-geni-qcom. +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 @@ -110,6 +110,7 @@ obj-$(CONFIG_SPI_RB4XX) += spi-rb4xx.o obj-$(CONFIG_MACH_REALTEK_RTL) += spi-realtek-rtl.o obj-$(CONFIG_SPI_RPCIF) += spi-rpc-if.o obj-$(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 obj-$(CONFIG_SPI_S3C64XX) += spi-s3c64xx.o --- /dev/null +++ b/drivers/spi/spi-rt2880.c @@ -0,0 +1,535 @@ +/* + * spi-rt2880.c -- Ralink RT288x/RT305x SPI controller driver + * + * Copyright (C) 2011 Sergiy + * Copyright (C) 2011-2013 Gabor Juhos + * + * Some parts are based on spi-orion.c: + * Author: Shadi Ammouri + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRIVER_NAME "spi-rt2880" + +#define RAMIPS_SPI_STAT 0x00 +#define RAMIPS_SPI_CFG 0x10 +#define RAMIPS_SPI_CTL 0x14 +#define RAMIPS_SPI_DATA 0x20 +#define RAMIPS_SPI_ADDR 0x24 +#define RAMIPS_SPI_BS 0x28 +#define RAMIPS_SPI_USER 0x2C +#define RAMIPS_SPI_TXFIFO 0x30 +#define RAMIPS_SPI_RXFIFO 0x34 +#define RAMIPS_SPI_FIFO_STAT 0x38 +#define RAMIPS_SPI_MODE 0x3C +#define RAMIPS_SPI_DEV_OFFSET 0x40 +#define RAMIPS_SPI_DMA 0x80 +#define RAMIPS_SPI_DMASTAT 0x84 +#define RAMIPS_SPI_ARBITER 0xF0 + +/* SPISTAT register bit field */ +#define SPISTAT_BUSY BIT(0) + +/* SPICFG register bit field */ +#define SPICFG_ADDRMODE BIT(12) +#define SPICFG_RXENVDIS BIT(11) +#define SPICFG_RXCAP BIT(10) +#define SPICFG_SPIENMODE BIT(9) +#define SPICFG_MSBFIRST BIT(8) +#define SPICFG_SPICLKPOL BIT(6) +#define SPICFG_RXCLKEDGE_FALLING BIT(5) +#define SPICFG_TXCLKEDGE_FALLING BIT(4) +#define SPICFG_HIZSPI BIT(3) +#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_START BIT(4) +#define SPICTL_HIZSDO BIT(3) +#define SPICTL_STARTWR BIT(2) +#define SPICTL_STARTRD BIT(1) +#define SPICTL_SPIENA BIT(0) + +/* SPIUSER register bit field */ +#define SPIUSER_USERMODE BIT(21) +#define SPIUSER_INSTR_PHASE BIT(20) +#define SPIUSER_ADDR_PHASE_MASK 0x7 +#define SPIUSER_ADDR_PHASE_OFFSET 17 +#define SPIUSER_MODE_PHASE BIT(16) +#define SPIUSER_DUMMY_PHASE_MASK 0x3 +#define SPIUSER_DUMMY_PHASE_OFFSET 14 +#define SPIUSER_DATA_PHASE_MASK 0x3 +#define SPIUSER_DATA_PHASE_OFFSET 12 +#define SPIUSER_DATA_READ (BIT(0) << SPIUSER_DATA_PHASE_OFFSET) +#define SPIUSER_DATA_WRITE (BIT(1) << SPIUSER_DATA_PHASE_OFFSET) +#define SPIUSER_ADDR_TYPE_OFFSET 9 +#define SPIUSER_MODE_TYPE_OFFSET 6 +#define SPIUSER_DUMMY_TYPE_OFFSET 3 +#define SPIUSER_DATA_TYPE_OFFSET 0 +#define SPIUSER_TRANSFER_MASK 0x7 +#define SPIUSER_TRANSFER_SINGLE BIT(0) +#define SPIUSER_TRANSFER_DUAL BIT(1) +#define SPIUSER_TRANSFER_QUAD BIT(2) + +#define SPIUSER_TRANSFER_TYPE(type) ( \ + (type << SPIUSER_ADDR_TYPE_OFFSET) | \ + (type << SPIUSER_MODE_TYPE_OFFSET) | \ + (type << SPIUSER_DUMMY_TYPE_OFFSET) | \ + (type << SPIUSER_DATA_TYPE_OFFSET) \ +) + +/* SPIFIFOSTAT register bit field */ +#define SPIFIFOSTAT_TXEMPTY BIT(19) +#define SPIFIFOSTAT_RXEMPTY BIT(18) +#define SPIFIFOSTAT_TXFULL BIT(17) +#define SPIFIFOSTAT_RXFULL BIT(16) +#define SPIFIFOSTAT_FIFO_MASK 0xff +#define SPIFIFOSTAT_TX_OFFSET 8 +#define SPIFIFOSTAT_RX_OFFSET 0 + +#define SPI_FIFO_DEPTH 16 + +/* SPIMODE register bit field */ +#define SPIMODE_MODE_OFFSET 24 +#define SPIMODE_DUMMY_OFFSET 0 + +/* SPIARB register bit field */ +#define SPICTL_ARB_EN BIT(31) +#define SPICTL_CSCTL1 BIT(16) +#define SPI1_POR BIT(1) +#define SPI0_POR BIT(0) + +#define RT2880_SPI_MODE_BITS (SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | \ + SPI_CS_HIGH) + +static atomic_t hw_reset_count = ATOMIC_INIT(0); + +struct rt2880_spi { + struct spi_master *master; + void __iomem *base; + u32 speed; + u16 wait_loops; + u16 mode; + struct clk *clk; +}; + +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, + const 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; + + iowrite32((ioread32(addr) | mask), addr); +} + +static inline void rt2880_spi_clrbits(struct rt2880_spi *rs, u32 reg, u32 mask) +{ + void __iomem *addr = rs->base + reg; + + iowrite32((ioread32(addr) & ~mask), addr); +} + +static u32 rt2880_spi_baudrate_get(struct spi_device *spi, unsigned int speed) +{ + struct rt2880_spi *rs = spidev_to_rt2880_spi(spi); + u32 rate; + u32 prescale; + + /* + * the supported rates are: 2, 4, 8, ... 128 + * round up as we look for equal or less speed + */ + rate = DIV_ROUND_UP(clk_get_rate(rs->clk), speed); + rate = roundup_pow_of_two(rate); + + /* Convert the rate to SPI clock divisor value. */ + prescale = ilog2(rate / 2); + + /* some tolerance. double and add 100 */ + rs->wait_loops = (8 * HZ * loops_per_jiffy) / + (clk_get_rate(rs->clk) / rate); + rs->wait_loops = (rs->wait_loops << 1) + 100; + rs->speed = speed; + + dev_dbg(&spi->dev, "speed: %lu/%u, rate: %u, prescal: %u, loops: %hu\n", + clk_get_rate(rs->clk) / rate, speed, rate, prescale, + rs->wait_loops); + + return prescale; +} + +static u32 get_arbiter_offset(struct spi_master *master) +{ + u32 offset; + + offset = RAMIPS_SPI_ARBITER; + if (master->bus_num == 1) + offset -= RAMIPS_SPI_DEV_OFFSET; + + return offset; +} + +static void rt2880_spi_set_cs(struct spi_device *spi, bool enable) +{ + struct rt2880_spi *rs = spidev_to_rt2880_spi(spi); + + if (enable) + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA); + else + rt2880_spi_clrbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA); +} + +static int rt2880_spi_wait_ready(struct rt2880_spi *rs, int len) +{ + int loop = rs->wait_loops * len; + + while ((rt2880_spi_read(rs, RAMIPS_SPI_STAT) & SPISTAT_BUSY) && --loop) + cpu_relax(); + + if (loop) + return 0; + + return -ETIMEDOUT; +} + +static void rt2880_dump_reg(struct spi_master *master) +{ + struct rt2880_spi *rs = spi_master_get_devdata(master); + + dev_dbg(&master->dev, "stat: %08x, cfg: %08x, ctl: %08x, " \ + "data: %08x, arb: %08x\n", + rt2880_spi_read(rs, RAMIPS_SPI_STAT), + rt2880_spi_read(rs, RAMIPS_SPI_CFG), + rt2880_spi_read(rs, RAMIPS_SPI_CTL), + rt2880_spi_read(rs, RAMIPS_SPI_DATA), + rt2880_spi_read(rs, get_arbiter_offset(master))); +} + +static int rt2880_spi_transfer_one(struct spi_master *master, + struct spi_device *spi, struct spi_transfer *xfer) +{ + struct rt2880_spi *rs = spi_master_get_devdata(master); + unsigned len; + const u8 *tx = xfer->tx_buf; + u8 *rx = xfer->rx_buf; + int err = 0; + + /* change clock speed */ + if (unlikely(rs->speed != xfer->speed_hz)) { + u32 reg; + reg = rt2880_spi_read(rs, RAMIPS_SPI_CFG); + reg &= ~SPICFG_SPICLK_PRESCALE_MASK; + reg |= rt2880_spi_baudrate_get(spi, xfer->speed_hz); + rt2880_spi_write(rs, RAMIPS_SPI_CFG, reg); + } + + if (tx) { + len = xfer->len; + while (len-- > 0) { + rt2880_spi_write(rs, RAMIPS_SPI_DATA, *tx++); + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTWR); + err = rt2880_spi_wait_ready(rs, 1); + if (err) { + dev_err(&spi->dev, "TX failed, err=%d\n", err); + goto out; + } + } + } + + if (rx) { + len = xfer->len; + while (len-- > 0) { + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTRD); + err = rt2880_spi_wait_ready(rs, 1); + if (err) { + dev_err(&spi->dev, "RX failed, err=%d\n", err); + goto out; + } + *rx++ = (u8) rt2880_spi_read(rs, RAMIPS_SPI_DATA); + } + } + +out: + return err; +} + +/* copy from spi.c */ +static void spi_set_cs(struct spi_device *spi, bool enable) +{ + if (spi->mode & SPI_CS_HIGH) + enable = !enable; + + if (spi->cs_gpiod) + gpiod_set_value(spi->cs_gpiod, !enable); + else if (spi->master->set_cs) + spi->master->set_cs(spi, !enable); +} + +static int rt2880_spi_setup(struct spi_device *spi) +{ + struct spi_master *master = spi->master; + struct rt2880_spi *rs = spi_master_get_devdata(master); + u32 reg, old_reg, arbit_off; + + if ((spi->max_speed_hz > master->max_speed_hz) || + (spi->max_speed_hz < master->min_speed_hz)) { + dev_err(&spi->dev, "invalide requested speed %d Hz\n", + spi->max_speed_hz); + return -EINVAL; + } + + if (!(master->bits_per_word_mask & + BIT(spi->bits_per_word - 1))) { + dev_err(&spi->dev, "invalide bits_per_word %d\n", + spi->bits_per_word); + return -EINVAL; + } + + /* the hardware seems can't work on mode0 force it to mode3 */ + if ((spi->mode & (SPI_CPOL | SPI_CPHA)) == SPI_MODE_0) { + dev_warn(&spi->dev, "force spi mode3\n"); + spi->mode |= SPI_MODE_3; + } + + /* chip polarity */ + arbit_off = get_arbiter_offset(master); + reg = old_reg = rt2880_spi_read(rs, arbit_off); + if (spi->mode & SPI_CS_HIGH) { + switch (master->bus_num) { + case 1: + reg |= SPI1_POR; + break; + default: + reg |= SPI0_POR; + break; + } + } else { + switch (master->bus_num) { + case 1: + reg &= ~SPI1_POR; + break; + default: + reg &= ~SPI0_POR; + break; + } + } + + /* enable spi1 */ + if (master->bus_num == 1) + reg |= SPICTL_ARB_EN; + + if (reg != old_reg) + rt2880_spi_write(rs, arbit_off, reg); + + /* deselected the spi device */ + spi_set_cs(spi, false); + + rt2880_dump_reg(master); + + return 0; +} + +static int rt2880_spi_prepare_message(struct spi_master *master, + struct spi_message *msg) +{ + struct rt2880_spi *rs = spi_master_get_devdata(master); + struct spi_device *spi = msg->spi; + u32 reg; + + if ((rs->mode == spi->mode) && (rs->speed == spi->max_speed_hz)) + return 0; + +#if 0 + /* set spido to tri-state */ + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_HIZSDO); +#endif + + reg = rt2880_spi_read(rs, RAMIPS_SPI_CFG); + + reg &= ~(SPICFG_MSBFIRST | SPICFG_SPICLKPOL | + SPICFG_RXCLKEDGE_FALLING | + SPICFG_TXCLKEDGE_FALLING | + SPICFG_SPICLK_PRESCALE_MASK); + + /* MSB */ + if (!(spi->mode & SPI_LSB_FIRST)) + reg |= SPICFG_MSBFIRST; + + /* spi mode */ + switch (spi->mode & (SPI_CPOL | SPI_CPHA)) { + case SPI_MODE_0: + reg |= SPICFG_TXCLKEDGE_FALLING; + break; + case SPI_MODE_1: + reg |= SPICFG_RXCLKEDGE_FALLING; + break; + case SPI_MODE_2: + reg |= SPICFG_SPICLKPOL | SPICFG_RXCLKEDGE_FALLING; + break; + case SPI_MODE_3: + reg |= SPICFG_SPICLKPOL | SPICFG_TXCLKEDGE_FALLING; + break; + } + rs->mode = spi->mode; + +#if 0 + /* set spiclk and spiena to tri-state */ + reg |= SPICFG_HIZSPI; +#endif + + /* clock divide */ + reg |= rt2880_spi_baudrate_get(spi, spi->max_speed_hz); + + rt2880_spi_write(rs, RAMIPS_SPI_CFG, reg); + + return 0; +} + +static int rt2880_spi_probe(struct platform_device *pdev) +{ + struct spi_master *master; + struct rt2880_spi *rs; + void __iomem *base; + struct resource *r; + struct clk *clk; + int ret; + + 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\n"); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) + goto err_clk; + + master = spi_alloc_master(&pdev->dev, sizeof(*rs)); + if (master == NULL) { + dev_dbg(&pdev->dev, "master allocation failed\n"); + ret = -ENOMEM; + goto err_clk; + } + + master->dev.of_node = pdev->dev.of_node; + master->mode_bits = RT2880_SPI_MODE_BITS; + master->bits_per_word_mask = SPI_BPW_MASK(8); + master->min_speed_hz = clk_get_rate(clk) / 128; + master->max_speed_hz = clk_get_rate(clk) / 2; + master->flags = SPI_MASTER_HALF_DUPLEX; + master->setup = rt2880_spi_setup; + master->prepare_message = rt2880_spi_prepare_message; + master->set_cs = rt2880_spi_set_cs; + master->transfer_one = rt2880_spi_transfer_one, + + dev_set_drvdata(&pdev->dev, master); + + rs = spi_master_get_devdata(master); + rs->master = master; + rs->base = base; + rs->clk = clk; + + if (atomic_inc_return(&hw_reset_count) == 1) { + ret = device_reset(&pdev->dev); + if (ret) { + dev_err(&pdev->dev, "device_reset error.\n"); + goto err_master; + } + } + + ret = devm_spi_register_master(&pdev->dev, master); + if (ret < 0) { + dev_err(&pdev->dev, "devm_spi_register_master error.\n"); + goto err_master; + } + + return ret; + +err_master: + spi_master_put(master); + kfree(master); +err_clk: + clk_disable_unprepare(clk); + + return ret; +} + +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_unprepare(rs->clk); + atomic_dec(&hw_reset_count); + + 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 "); +MODULE_AUTHOR("Gabor Juhos "); +MODULE_LICENSE("GPL");