spi: Add Faraday SPI controller support

The Faraday FTSSP010 is a multi-function controller
which supports I2S/SPI/SSP/AC97/SPDIF. However This
patch implements only the SPI mode.

NOTE:
The DMA and CS/Clock control logic has been altered
since hardware revision 1.19.0. So this patch
would first detects the revision id of the underlying
chip, and then switch to the corresponding software
control routines.

Signed-off-by: Kuo-Jung Su <dantesu@faraday-tech.com>
Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
CC: Tom Rini <trini@ti.com>

2 files changed, 509 insertions, 0 deletions

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index d5a7143..81b6af6 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_CF_SPI) += cf_spi.o
 obj-$(CONFIG_CF_QSPI) += cf_qspi.o
 obj-$(CONFIG_DAVINCI_SPI) += davinci_spi.o
 obj-$(CONFIG_EXYNOS_SPI) += exynos_spi.o
+obj-$(CONFIG_FTSSP010_SPI) += ftssp010_spi.o
 obj-$(CONFIG_ICH_SPI) +=  ich.o
 obj-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
 obj-$(CONFIG_MPC52XX_SPI) += mpc52xx_spi.o
diff --git a/drivers/spi/ftssp010_spi.c b/drivers/spi/ftssp010_spi.c
new file mode 100644
index 0000000..aa3b5a0
--- /dev/null
+++ b/drivers/spi/ftssp010_spi.c
@@ -0,0 +1,508 @@
+/*
+ * (C) Copyright 2013
+ * Faraday Technology Corporation. <http://www.faraday-tech.com/tw/>
+ * Kuo-Jung Su <dantesu@gmail.com>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <linux/compat.h>
+#include <asm/io.h>
+#include <malloc.h>
+#include <spi.h>
+
+#ifndef CONFIG_FTSSP010_BASE_LIST
+#define CONFIG_FTSSP010_BASE_LIST   { CONFIG_FTSSP010_BASE }
+#endif
+
+#ifndef CONFIG_FTSSP010_GPIO_BASE
+#define CONFIG_FTSSP010_GPIO_BASE   0
+#endif
+
+#ifndef CONFIG_FTSSP010_GPIO_LIST
+#define CONFIG_FTSSP010_GPIO_LIST   { CONFIG_FTSSP010_GPIO_BASE }
+#endif
+
+#ifndef CONFIG_FTSSP010_CLOCK
+#define CONFIG_FTSSP010_CLOCK       clk_get_rate("SSP");
+#endif
+
+#ifndef CONFIG_FTSSP010_TIMEOUT
+#define CONFIG_FTSSP010_TIMEOUT     100
+#endif
+
+/* FTSSP010 chip registers */
+struct ftssp010_regs {
+	uint32_t cr[3];/* control register */
+	uint32_t sr;   /* status register */
+	uint32_t icr;  /* interrupt control register */
+	uint32_t isr;  /* interrupt status register */
+	uint32_t dr;   /* data register */
+	uint32_t rsvd[17];
+	uint32_t revr; /* revision register */
+	uint32_t fear; /* feature register */
+};
+
+/* Control Register 0  */
+#define CR0_FFMT_MASK       (7 << 12)
+#define CR0_FFMT_SSP        (0 << 12)
+#define CR0_FFMT_SPI        (1 << 12)
+#define CR0_FFMT_MICROWIRE  (2 << 12)
+#define CR0_FFMT_I2S        (3 << 12)
+#define CR0_FFMT_AC97       (4 << 12)
+#define CR0_FLASH           (1 << 11)
+#define CR0_FSDIST(x)       (((x) & 0x03) << 8)
+#define CR0_LOOP            (1 << 7)  /* loopback mode */
+#define CR0_LSB             (1 << 6)  /* LSB */
+#define CR0_FSPO            (1 << 5)  /* fs atcive low (I2S only) */
+#define CR0_FSJUSTIFY       (1 << 4)
+#define CR0_OPM_SLAVE       (0 << 2)
+#define CR0_OPM_MASTER      (3 << 2)
+#define CR0_OPM_I2S_MSST    (3 << 2)  /* master stereo mode */
+#define CR0_OPM_I2S_MSMO    (2 << 2)  /* master mono mode */
+#define CR0_OPM_I2S_SLST    (1 << 2)  /* slave stereo mode */
+#define CR0_OPM_I2S_SLMO    (0 << 2)  /* slave mono mode */
+#define CR0_SCLKPO          (1 << 1)  /* clock polarity */
+#define CR0_SCLKPH          (1 << 0)  /* clock phase */
+
+/* Control Register 1 */
+#define CR1_PDL(x)   (((x) & 0xff) << 24) /* padding length */
+#define CR1_SDL(x)   ((((x) - 1) & 0x1f) << 16) /* data length */
+#define CR1_DIV(x)   (((x) - 1) & 0xffff) /* clock divider */
+
+/* Control Register 2 */
+#define CR2_CS(x)    (((x) & 3) << 10) /* CS/FS select */
+#define CR2_FS       (1 << 9) /* CS/FS signal level */
+#define CR2_TXEN     (1 << 8) /* tx enable */
+#define CR2_RXEN     (1 << 7) /* rx enable */
+#define CR2_RESET    (1 << 6) /* chip reset */
+#define CR2_TXFC     (1 << 3) /* tx fifo Clear */
+#define CR2_RXFC     (1 << 2) /* rx fifo Clear */
+#define CR2_TXDOE    (1 << 1) /* tx data output enable */
+#define CR2_EN       (1 << 0) /* chip enable */
+
+/* Status Register */
+#define SR_RFF       (1 << 0) /* rx fifo full */
+#define SR_TFNF      (1 << 1) /* tx fifo not full */
+#define SR_BUSY      (1 << 2) /* chip busy */
+#define SR_RFVE(reg) (((reg) >> 4) & 0x1f)  /* rx fifo valid entries */
+#define SR_TFVE(reg) (((reg) >> 12) & 0x1f) /* tx fifo valid entries */
+
+/* Feature Register */
+#define FEAR_BITS(reg)   ((((reg) >>  0) & 0xff) + 1) /* data width */
+#define FEAR_RFSZ(reg)   ((((reg) >>  8) & 0xff) + 1) /* rx fifo size */
+#define FEAR_TFSZ(reg)   ((((reg) >> 16) & 0xff) + 1) /* tx fifo size */
+#define FEAR_AC97        (1 << 24)
+#define FEAR_I2S         (1 << 25)
+#define FEAR_SPI_MWR     (1 << 26)
+#define FEAR_SSP         (1 << 27)
+#define FEAR_SPDIF       (1 << 28)
+
+/* FTGPIO010 chip registers */
+struct ftgpio010_regs {
+	uint32_t out;     /* 0x00: Data Output */
+	uint32_t in;      /* 0x04: Data Input */
+	uint32_t dir;     /* 0x08: Direction */
+	uint32_t bypass;  /* 0x0c: Bypass */
+	uint32_t set;     /* 0x10: Data Set */
+	uint32_t clr;     /* 0x14: Data Clear */
+	uint32_t pull_up; /* 0x18: Pull-Up Enabled */
+	uint32_t pull_st; /* 0x1c: Pull State (0=pull-down, 1=pull-up) */
+};
+
+struct ftssp010_gpio {
+	struct ftgpio010_regs *regs;
+	uint32_t pin;
+};
+
+struct ftssp010_spi {
+	struct spi_slave slave;
+	struct ftssp010_gpio gpio;
+	struct ftssp010_regs *regs;
+	uint32_t fifo;
+	uint32_t mode;
+	uint32_t div;
+	uint32_t clk;
+	uint32_t speed;
+	uint32_t revision;
+};
+
+static inline struct ftssp010_spi *to_ftssp010_spi(struct spi_slave *slave)
+{
+	return container_of(slave, struct ftssp010_spi, slave);
+}
+
+static int get_spi_chip(int bus, struct ftssp010_spi *chip)
+{
+	uint32_t fear, base[] = CONFIG_FTSSP010_BASE_LIST;
+
+	if (bus >= ARRAY_SIZE(base) || !base[bus])
+		return -1;
+
+	chip->regs = (struct ftssp010_regs *)base[bus];
+
+	chip->revision = readl(&chip->regs->revr);
+
+	fear = readl(&chip->regs->fear);
+	chip->fifo = min_t(uint32_t, FEAR_TFSZ(fear), FEAR_RFSZ(fear));
+
+	return 0;
+}
+
+static int get_spi_gpio(int bus, struct ftssp010_gpio *chip)
+{
+	uint32_t base[] = CONFIG_FTSSP010_GPIO_LIST;
+
+	if (bus >= ARRAY_SIZE(base) || !base[bus])
+		return -1;
+
+	chip->regs = (struct ftgpio010_regs *)(base[bus] & 0xfff00000);
+	chip->pin = base[bus] & 0x1f;
+
+	/* make it an output pin */
+	setbits_le32(&chip->regs->dir, 1 << chip->pin);
+
+	return 0;
+}
+
+static int ftssp010_wait(struct ftssp010_spi *chip)
+{
+	struct ftssp010_regs *regs = chip->regs;
+	int ret = -1;
+	ulong t;
+
+	/* wait until device idle */
+	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
+		if (readl(&regs->sr) & SR_BUSY)
+			continue;
+		ret = 0;
+		break;
+	}
+
+	if (ret)
+		puts("ftspi010: busy timeout\n");
+
+	return ret;
+}
+
+static int ftssp010_wait_tx(struct ftssp010_spi *chip)
+{
+	struct ftssp010_regs *regs = chip->regs;
+	int ret = -1;
+	ulong t;
+
+	/* wait until tx fifo not full */
+	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
+		if (!(readl(&regs->sr) & SR_TFNF))
+			continue;
+		ret = 0;
+		break;
+	}
+
+	if (ret)
+		puts("ftssp010: tx timeout\n");
+
+	return ret;
+}
+
+static int ftssp010_wait_rx(struct ftssp010_spi *chip)
+{
+	struct ftssp010_regs *regs = chip->regs;
+	int ret = -1;
+	ulong t;
+
+	/* wait until rx fifo not empty */
+	for (t = get_timer(0); get_timer(t) < CONFIG_FTSSP010_TIMEOUT; ) {
+		if (!SR_RFVE(readl(&regs->sr)))
+			continue;
+		ret = 0;
+		break;
+	}
+
+	if (ret)
+		puts("ftssp010: rx timeout\n");
+
+	return ret;
+}
+
+static int ftssp010_spi_work_transfer_v2(struct ftssp010_spi *chip,
+	const void *tx_buf, void *rx_buf, int len, uint flags)
+{
+	struct ftssp010_regs *regs = chip->regs;
+	const uint8_t *txb = tx_buf;
+	uint8_t       *rxb = rx_buf;
+
+	while (len > 0) {
+		int i, depth = min(chip->fifo >> 2, len);
+		uint32_t xmsk = 0;
+
+		if (tx_buf) {
+			for (i = 0; i < depth; ++i) {
+				ftssp010_wait_tx(chip);
+				writel(*txb++, &regs->dr);
+			}
+			xmsk |= CR2_TXEN | CR2_TXDOE;
+			if ((readl(&regs->cr[2]) & xmsk) != xmsk)
+				setbits_le32(&regs->cr[2], xmsk);
+		}
+		if (rx_buf) {
+			xmsk |= CR2_RXEN;
+			if ((readl(&regs->cr[2]) & xmsk) != xmsk)
+				setbits_le32(&regs->cr[2], xmsk);
+			for (i = 0; i < depth; ++i) {
+				ftssp010_wait_rx(chip);
+				*rxb++ = (uint8_t)readl(&regs->dr);
+			}
+		}
+
+		len -= depth;
+	}
+
+	return 0;
+}
+
+static int ftssp010_spi_work_transfer_v1(struct ftssp010_spi *chip,
+	const void *tx_buf, void *rx_buf, int len, uint flags)
+{
+	struct ftssp010_regs *regs = chip->regs;
+	const uint8_t *txb = tx_buf;
+	uint8_t       *rxb = rx_buf;
+
+	while (len > 0) {
+		int i, depth = min(chip->fifo >> 2, len);
+		uint32_t tmp;
+
+		for (i = 0; i < depth; ++i) {
+			ftssp010_wait_tx(chip);
+			writel(txb ? (*txb++) : 0, &regs->dr);
+		}
+		for (i = 0; i < depth; ++i) {
+			ftssp010_wait_rx(chip);
+			tmp = readl(&regs->dr);
+			if (rxb)
+				*rxb++ = (uint8_t)tmp;
+		}
+
+		len -= depth;
+	}
+
+	return 0;
+}
+
+static void ftssp010_cs_set(struct ftssp010_spi *chip, int high)
+{
+	struct ftssp010_regs *regs = chip->regs;
+	struct ftssp010_gpio *gpio = &chip->gpio;
+	uint32_t mask;
+
+	/* cs pull high/low */
+	if (chip->revision >= 0x11900) {
+		mask = CR2_CS(chip->slave.cs) | (high ? CR2_FS : 0);
+		writel(mask, &regs->cr[2]);
+	} else if (gpio->regs) {
+		mask = 1 << gpio->pin;
+		if (high)
+			writel(mask, &gpio->regs->set);
+		else
+			writel(mask, &gpio->regs->clr);
+	}
+
+	/* extra delay for signal propagation */
+	udelay_masked(1);
+}
+
+/*
+ * Determine if a SPI chipselect is valid.
+ * This function is provided by the board if the low-level SPI driver
+ * needs it to determine if a given chipselect is actually valid.
+ *
+ * Returns: 1 if bus:cs identifies a valid chip on this board, 0
+ * otherwise.
+ */
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	struct ftssp010_spi chip;
+
+	if (get_spi_chip(bus, &chip))
+		return 0;
+
+	if (!cs)
+		return 1;
+	else if ((cs < 4) && (chip.revision >= 0x11900))
+		return 1;
+
+	return 0;
+}
+
+/*
+ * Activate a SPI chipselect.
+ * This function is provided by the board code when using a driver
+ * that can't control its chipselects automatically (e.g.
+ * common/soft_spi.c). When called, it should activate the chip select
+ * to the device identified by "slave".
+ */
+void spi_cs_activate(struct spi_slave *slave)
+{
+	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
+	struct ftssp010_regs *regs = chip->regs;
+
+	/* cs pull */
+	if (chip->mode & SPI_CS_HIGH)
+		ftssp010_cs_set(chip, 1);
+	else
+		ftssp010_cs_set(chip, 0);
+
+	/* chip enable + fifo clear */
+	setbits_le32(&regs->cr[2], CR2_EN | CR2_TXFC | CR2_RXFC);
+}
+
+/*
+ * Deactivate a SPI chipselect.
+ * This function is provided by the board code when using a driver
+ * that can't control its chipselects automatically (e.g.
+ * common/soft_spi.c). When called, it should deactivate the chip
+ * select to the device identified by "slave".
+ */
+void spi_cs_deactivate(struct spi_slave *slave)
+{
+	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
+
+	/* wait until chip idle */
+	ftssp010_wait(chip);
+
+	/* cs pull */
+	if (chip->mode & SPI_CS_HIGH)
+		ftssp010_cs_set(chip, 0);
+	else
+		ftssp010_cs_set(chip, 1);
+}
+
+void spi_init(void)
+{
+	/* nothing to do */
+}
+
+struct spi_slave *spi_setup_slave(uint bus, uint cs, uint max_hz, uint mode)
+{
+	struct ftssp010_spi *chip;
+
+	if (mode & SPI_3WIRE) {
+		puts("ftssp010: can't do 3-wire\n");
+		return NULL;
+	}
+
+	if (mode & SPI_SLAVE) {
+		puts("ftssp010: can't do slave mode\n");
+		return NULL;
+	}
+
+	if (mode & SPI_PREAMBLE) {
+		puts("ftssp010: can't skip preamble bytes\n");
+		return NULL;
+	}
+
+	if (!spi_cs_is_valid(bus, cs)) {
+		puts("ftssp010: invalid (bus, cs)\n");
+		return NULL;
+	}
+
+	chip = spi_alloc_slave(struct ftssp010_spi, bus, cs);
+	if (!chip)
+		return NULL;
+
+	if (get_spi_chip(bus, chip))
+		goto free_out;
+
+	if (chip->revision < 0x11900 && get_spi_gpio(bus, &chip->gpio)) {
+		puts("ftssp010: Before revision 1.19.0, its clock & cs are\n"
+		"controlled by tx engine which is not synced with rx engine,\n"
+		"so the clock & cs might be shutdown before rx engine\n"
+		"finishs its jobs.\n"
+		"If possible, please add a dedicated gpio for it.\n");
+	}
+
+	chip->mode = mode;
+	chip->clk = CONFIG_FTSSP010_CLOCK;
+	chip->div = 2;
+	if (max_hz) {
+		while (chip->div < 0xffff) {
+			if ((chip->clk / (2 * chip->div)) <= max_hz)
+				break;
+			chip->div += 1;
+		}
+	}
+	chip->speed = chip->clk / (2 * chip->div);
+
+	return &chip->slave;
+
+free_out:
+	free(chip);
+	return NULL;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	free(slave);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
+	struct ftssp010_regs *regs = chip->regs;
+
+	writel(CR1_SDL(8) | CR1_DIV(chip->div), &regs->cr[1]);
+
+	if (chip->revision >= 0x11900) {
+		writel(CR0_OPM_MASTER | CR0_FFMT_SPI | CR0_FSPO | CR0_FLASH,
+		       &regs->cr[0]);
+		writel(CR2_TXFC | CR2_RXFC,
+		       &regs->cr[2]);
+	} else {
+		writel(CR0_OPM_MASTER | CR0_FFMT_SPI | CR0_FSPO,
+		       &regs->cr[0]);
+		writel(CR2_TXFC | CR2_RXFC | CR2_EN | CR2_TXDOE,
+		       &regs->cr[2]);
+	}
+
+	if (chip->mode & SPI_LOOP)
+		setbits_le32(&regs->cr[0], CR0_LOOP);
+
+	if (chip->mode & SPI_CPOL)
+		setbits_le32(&regs->cr[0], CR0_SCLKPO);
+
+	if (chip->mode & SPI_CPHA)
+		setbits_le32(&regs->cr[0], CR0_SCLKPH);
+
+	spi_cs_deactivate(slave);
+
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
+	struct ftssp010_regs *regs = chip->regs;
+
+	writel(0, &regs->cr[2]);
+}
+
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+			 const void *dout, void *din, unsigned long flags)
+{
+	struct ftssp010_spi *chip = to_ftssp010_spi(slave);
+	uint32_t len = bitlen >> 3;
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	if (chip->revision >= 0x11900)
+		ftssp010_spi_work_transfer_v2(chip, dout, din, len, flags);
+	else
+		ftssp010_spi_work_transfer_v1(chip, dout, din, len, flags);
+
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return 0;
+}