--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * uniphier_spi.c - Socionext UniPhier SPI driver
+ * Copyright 2019 Socionext, Inc.
+ */
+
+#include <clk.h>
+#include <common.h>
+#include <dm.h>
+#include <linux/bitfield.h>
+#include <linux/io.h>
+#include <spi.h>
+#include <wait_bit.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define SSI_CTL 0x00
+#define SSI_CTL_EN BIT(0)
+
+#define SSI_CKS 0x04
+#define SSI_CKS_CKRAT_MASK GENMASK(7, 0)
+#define SSI_CKS_CKPHS BIT(14)
+#define SSI_CKS_CKINIT BIT(13)
+#define SSI_CKS_CKDLY BIT(12)
+
+#define SSI_TXWDS 0x08
+#define SSI_TXWDS_WDLEN_MASK GENMASK(13, 8)
+#define SSI_TXWDS_TDTF_MASK GENMASK(7, 6)
+#define SSI_TXWDS_DTLEN_MASK GENMASK(5, 0)
+
+#define SSI_RXWDS 0x0c
+#define SSI_RXWDS_RDTF_MASK GENMASK(7, 6)
+#define SSI_RXWDS_DTLEN_MASK GENMASK(5, 0)
+
+#define SSI_FPS 0x10
+#define SSI_FPS_FSPOL BIT(15)
+#define SSI_FPS_FSTRT BIT(14)
+
+#define SSI_SR 0x14
+#define SSI_SR_BUSY BIT(7)
+#define SSI_SR_TNF BIT(5)
+#define SSI_SR_RNE BIT(0)
+
+#define SSI_IE 0x18
+
+#define SSI_IC 0x1c
+#define SSI_IC_TCIC BIT(4)
+#define SSI_IC_RCIC BIT(3)
+#define SSI_IC_RORIC BIT(0)
+
+#define SSI_FC 0x20
+#define SSI_FC_TXFFL BIT(12)
+#define SSI_FC_TXFTH_MASK GENMASK(11, 8)
+#define SSI_FC_RXFFL BIT(4)
+#define SSI_FC_RXFTH_MASK GENMASK(3, 0)
+
+#define SSI_XDR 0x24 /* TXDR for write, RXDR for read */
+
+#define SSI_FIFO_DEPTH 8U
+
+#define SSI_REG_TIMEOUT (CONFIG_SYS_HZ / 100) /* 10 ms */
+#define SSI_XFER_TIMEOUT (CONFIG_SYS_HZ) /* 1 sec */
+
+#define SSI_CLK 50000000 /* internal I/O clock: 50MHz */
+
+struct uniphier_spi_platdata {
+ void __iomem *base;
+ u32 frequency; /* input frequency */
+ u32 speed_hz;
+ uint deactivate_delay_us; /* Delay to wait after deactivate */
+ uint activate_delay_us; /* Delay to wait after activate */
+};
+
+struct uniphier_spi_priv {
+ void __iomem *base;
+ u8 mode;
+ u8 fifo_depth;
+ u8 bits_per_word;
+ ulong last_transaction_us; /* Time of last transaction end */
+};
+
+static void uniphier_spi_enable(struct uniphier_spi_priv *priv, int enable)
+{
+ u32 val;
+
+ val = readl(priv->base + SSI_CTL);
+ if (enable)
+ val |= SSI_CTL_EN;
+ else
+ val &= ~SSI_CTL_EN;
+ writel(val, priv->base + SSI_CTL);
+}
+
+static void uniphier_spi_regdump(struct uniphier_spi_priv *priv)
+{
+ pr_debug("CTL %08x\n", readl(priv->base + SSI_CTL));
+ pr_debug("CKS %08x\n", readl(priv->base + SSI_CKS));
+ pr_debug("TXWDS %08x\n", readl(priv->base + SSI_TXWDS));
+ pr_debug("RXWDS %08x\n", readl(priv->base + SSI_RXWDS));
+ pr_debug("FPS %08x\n", readl(priv->base + SSI_FPS));
+ pr_debug("SR %08x\n", readl(priv->base + SSI_SR));
+ pr_debug("IE %08x\n", readl(priv->base + SSI_IE));
+ pr_debug("IC %08x\n", readl(priv->base + SSI_IC));
+ pr_debug("FC %08x\n", readl(priv->base + SSI_FC));
+ pr_debug("XDR %08x\n", readl(priv->base + SSI_XDR));
+}
+
+static void spi_cs_activate(struct udevice *dev)
+{
+ struct udevice *bus = dev->parent;
+ struct uniphier_spi_platdata *plat = bus->platdata;
+ struct uniphier_spi_priv *priv = dev_get_priv(bus);
+ ulong delay_us; /* The delay completed so far */
+ u32 val;
+
+ /* If it's too soon to do another transaction, wait */
+ if (plat->deactivate_delay_us && priv->last_transaction_us) {
+ delay_us = timer_get_us() - priv->last_transaction_us;
+ if (delay_us < plat->deactivate_delay_us)
+ udelay(plat->deactivate_delay_us - delay_us);
+ }
+
+ val = readl(priv->base + SSI_FPS);
+ if (priv->mode & SPI_CS_HIGH)
+ val |= SSI_FPS_FSPOL;
+ else
+ val &= ~SSI_FPS_FSPOL;
+ writel(val, priv->base + SSI_FPS);
+
+ if (plat->activate_delay_us)
+ udelay(plat->activate_delay_us);
+}
+
+static void spi_cs_deactivate(struct udevice *dev)
+{
+ struct udevice *bus = dev->parent;
+ struct uniphier_spi_platdata *plat = bus->platdata;
+ struct uniphier_spi_priv *priv = dev_get_priv(bus);
+ u32 val;
+
+ val = readl(priv->base + SSI_FPS);
+ if (priv->mode & SPI_CS_HIGH)
+ val &= ~SSI_FPS_FSPOL;
+ else
+ val |= SSI_FPS_FSPOL;
+ writel(val, priv->base + SSI_FPS);
+
+ /* Remember time of this transaction so we can honour the bus delay */
+ if (plat->deactivate_delay_us)
+ priv->last_transaction_us = timer_get_us();
+}
+
+static int uniphier_spi_claim_bus(struct udevice *dev)
+{
+ struct udevice *bus = dev->parent;
+ struct uniphier_spi_priv *priv = dev_get_priv(bus);
+ u32 val, size;
+
+ uniphier_spi_enable(priv, false);
+
+ /* disable interrupts */
+ writel(0, priv->base + SSI_IE);
+
+ /* bits_per_word */
+ size = priv->bits_per_word;
+ val = readl(priv->base + SSI_TXWDS);
+ val &= ~(SSI_TXWDS_WDLEN_MASK | SSI_TXWDS_DTLEN_MASK);
+ val |= FIELD_PREP(SSI_TXWDS_WDLEN_MASK, size);
+ val |= FIELD_PREP(SSI_TXWDS_DTLEN_MASK, size);
+ writel(val, priv->base + SSI_TXWDS);
+
+ val = readl(priv->base + SSI_RXWDS);
+ val &= ~SSI_RXWDS_DTLEN_MASK;
+ val |= FIELD_PREP(SSI_RXWDS_DTLEN_MASK, size);
+ writel(val, priv->base + SSI_RXWDS);
+
+ /* reset FIFOs */
+ val = SSI_FC_TXFFL | SSI_FC_RXFFL;
+ writel(val, priv->base + SSI_FC);
+
+ /* FIFO threthold */
+ val = readl(priv->base + SSI_FC);
+ val &= ~(SSI_FC_TXFTH_MASK | SSI_FC_RXFTH_MASK);
+ val |= FIELD_PREP(SSI_FC_TXFTH_MASK, priv->fifo_depth);
+ val |= FIELD_PREP(SSI_FC_RXFTH_MASK, priv->fifo_depth);
+ writel(val, priv->base + SSI_FC);
+
+ /* clear interrupts */
+ writel(SSI_IC_TCIC | SSI_IC_RCIC | SSI_IC_RORIC,
+ priv->base + SSI_IC);
+
+ uniphier_spi_enable(priv, true);
+
+ return 0;
+}
+
+static int uniphier_spi_release_bus(struct udevice *dev)
+{
+ struct udevice *bus = dev->parent;
+ struct uniphier_spi_priv *priv = dev_get_priv(bus);
+
+ uniphier_spi_enable(priv, false);
+
+ return 0;
+}
+
+static int uniphier_spi_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct udevice *bus = dev->parent;
+ struct uniphier_spi_priv *priv = dev_get_priv(bus);
+ const u8 *tx_buf = dout;
+ u8 *rx_buf = din, buf;
+ u32 len = bitlen / 8;
+ u32 tx_len, rx_len;
+ u32 ts, status;
+ int ret = 0;
+
+ if (bitlen % 8) {
+ dev_err(dev, "Non byte aligned SPI transfer\n");
+ return -EINVAL;
+ }
+
+ if (flags & SPI_XFER_BEGIN)
+ spi_cs_activate(dev);
+
+ uniphier_spi_enable(priv, true);
+
+ ts = get_timer(0);
+ tx_len = len;
+ rx_len = len;
+
+ uniphier_spi_regdump(priv);
+
+ while (tx_len || rx_len) {
+ ret = wait_for_bit_le32(priv->base + SSI_SR, SSI_SR_BUSY, false,
+ SSI_REG_TIMEOUT * 1000, false);
+ if (ret) {
+ if (ret == -ETIMEDOUT)
+ dev_err(dev, "access timeout\n");
+ break;
+ }
+
+ status = readl(priv->base + SSI_SR);
+ /* write the data into TX */
+ if (tx_len && (status & SSI_SR_TNF)) {
+ buf = tx_buf ? *tx_buf++ : 0;
+ writel(buf, priv->base + SSI_XDR);
+ tx_len--;
+ }
+
+ /* read the data from RX */
+ if (rx_len && (status & SSI_SR_RNE)) {
+ buf = readl(priv->base + SSI_XDR);
+ if (rx_buf)
+ *rx_buf++ = buf;
+ rx_len--;
+ }
+
+ if (get_timer(ts) >= SSI_XFER_TIMEOUT) {
+ dev_err(dev, "transfer timeout\n");
+ ret = -ETIMEDOUT;
+ break;
+ }
+ }
+
+ if (flags & SPI_XFER_END)
+ spi_cs_deactivate(dev);
+
+ uniphier_spi_enable(priv, false);
+
+ return ret;
+}
+
+static int uniphier_spi_set_speed(struct udevice *bus, uint speed)
+{
+ struct uniphier_spi_platdata *plat = bus->platdata;
+ struct uniphier_spi_priv *priv = dev_get_priv(bus);
+ u32 val, ckdiv;
+
+ if (speed > plat->frequency)
+ speed = plat->frequency;
+
+ /* baudrate */
+ ckdiv = DIV_ROUND_UP(SSI_CLK, speed);
+ ckdiv = round_up(ckdiv, 2);
+
+ val = readl(priv->base + SSI_CKS);
+ val &= ~SSI_CKS_CKRAT_MASK;
+ val |= ckdiv & SSI_CKS_CKRAT_MASK;
+ writel(val, priv->base + SSI_CKS);
+
+ return 0;
+}
+
+static int uniphier_spi_set_mode(struct udevice *bus, uint mode)
+{
+ struct uniphier_spi_priv *priv = dev_get_priv(bus);
+ u32 val1, val2;
+
+ /*
+ * clock setting
+ * CKPHS capture timing. 0:rising edge, 1:falling edge
+ * CKINIT clock initial level. 0:low, 1:high
+ * CKDLY clock delay. 0:no delay, 1:delay depending on FSTRT
+ * (FSTRT=0: 1 clock, FSTRT=1: 0.5 clock)
+ *
+ * frame setting
+ * FSPOL frame signal porarity. 0: low, 1: high
+ * FSTRT start frame timing
+ * 0: rising edge of clock, 1: falling edge of clock
+ */
+ val1 = readl(priv->base + SSI_CKS);
+ val2 = readl(priv->base + SSI_FPS);
+
+ switch (mode & (SPI_CPOL | SPI_CPHA)) {
+ case SPI_MODE_0:
+ /* CKPHS=1, CKINIT=0, CKDLY=1, FSTRT=0 */
+ val1 |= SSI_CKS_CKPHS | SSI_CKS_CKDLY;
+ val1 &= ~SSI_CKS_CKINIT;
+ val2 &= ~SSI_FPS_FSTRT;
+ break;
+ case SPI_MODE_1:
+ /* CKPHS=0, CKINIT=0, CKDLY=0, FSTRT=1 */
+ val1 &= ~(SSI_CKS_CKPHS | SSI_CKS_CKINIT | SSI_CKS_CKDLY);
+ val2 |= SSI_FPS_FSTRT;
+ break;
+ case SPI_MODE_2:
+ /* CKPHS=0, CKINIT=1, CKDLY=1, FSTRT=1 */
+ val1 |= SSI_CKS_CKINIT | SSI_CKS_CKDLY;
+ val1 &= ~SSI_CKS_CKPHS;
+ val2 |= SSI_FPS_FSTRT;
+ break;
+ case SPI_MODE_3:
+ /* CKPHS=1, CKINIT=1, CKDLY=0, FSTRT=0 */
+ val1 |= SSI_CKS_CKPHS | SSI_CKS_CKINIT;
+ val1 &= ~SSI_CKS_CKDLY;
+ val2 &= ~SSI_FPS_FSTRT;
+ break;
+ }
+
+ writel(val1, priv->base + SSI_CKS);
+ writel(val2, priv->base + SSI_FPS);
+
+ /* format */
+ val1 = readl(priv->base + SSI_TXWDS);
+ val2 = readl(priv->base + SSI_RXWDS);
+ if (mode & SPI_LSB_FIRST) {
+ val1 |= FIELD_PREP(SSI_TXWDS_TDTF_MASK, 1);
+ val2 |= FIELD_PREP(SSI_RXWDS_RDTF_MASK, 1);
+ }
+ writel(val1, priv->base + SSI_TXWDS);
+ writel(val2, priv->base + SSI_RXWDS);
+
+ priv->mode = mode;
+
+ return 0;
+}
+
+static int uniphier_spi_ofdata_to_platdata(struct udevice *bus)
+{
+ struct uniphier_spi_platdata *plat = bus->platdata;
+ const void *blob = gd->fdt_blob;
+ int node = dev_of_offset(bus);
+
+ plat->base = devfdt_get_addr_ptr(bus);
+
+ plat->frequency =
+ fdtdec_get_int(blob, node, "spi-max-frequency", 12500000);
+ plat->deactivate_delay_us =
+ fdtdec_get_int(blob, node, "spi-deactivate-delay", 0);
+ plat->activate_delay_us =
+ fdtdec_get_int(blob, node, "spi-activate-delay", 0);
+ plat->speed_hz = plat->frequency / 2;
+
+ return 0;
+}
+
+static int uniphier_spi_probe(struct udevice *bus)
+{
+ struct uniphier_spi_platdata *plat = dev_get_platdata(bus);
+ struct uniphier_spi_priv *priv = dev_get_priv(bus);
+
+ priv->base = plat->base;
+ priv->fifo_depth = SSI_FIFO_DEPTH;
+ priv->bits_per_word = 8;
+
+ return 0;
+}
+
+static const struct dm_spi_ops uniphier_spi_ops = {
+ .claim_bus = uniphier_spi_claim_bus,
+ .release_bus = uniphier_spi_release_bus,
+ .xfer = uniphier_spi_xfer,
+ .set_speed = uniphier_spi_set_speed,
+ .set_mode = uniphier_spi_set_mode,
+};
+
+static const struct udevice_id uniphier_spi_ids[] = {
+ { .compatible = "socionext,uniphier-scssi" },
+ { /* Sentinel */ }
+};
+
+U_BOOT_DRIVER(uniphier_spi) = {
+ .name = "uniphier_spi",
+ .id = UCLASS_SPI,
+ .of_match = uniphier_spi_ids,
+ .ops = &uniphier_spi_ops,
+ .ofdata_to_platdata = uniphier_spi_ofdata_to_platdata,
+ .platdata_auto_alloc_size = sizeof(struct uniphier_spi_platdata),
+ .priv_auto_alloc_size = sizeof(struct uniphier_spi_priv),
+ .probe = uniphier_spi_probe,
+};
projects / u-boot.git / commitdiff