Add SPI controller driver implemented in Socionext UniPhier SoCs.
This controller has the SPI master mode only.

Signed-off-by: Kunihiko Hayashi <hayashi.kunih...@socionext.com>
---

Changes since v1:
- Replace <asm/io.h> with <linux/io.h> and sort headers in ascending order
- Change register accesses from structure use to direct macro use
- Remove unused macros
- Remove worthless comments
- Replace debug() and printf() with linux style functions
- Change SSI_TXDR and SSI_RXDR to SSI_XDR because of same address
- Use dev_err() for error messages
- Use devfdt_get_addr_ptr() instead of devfdt_get_addr()

 drivers/spi/Kconfig        |   8 +
 drivers/spi/Makefile       |   1 +
 drivers/spi/uniphier_spi.c | 413 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 422 insertions(+)
 create mode 100644 drivers/spi/uniphier_spi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 9469147..f3d26f4 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -285,6 +285,14 @@ config TI_QSPI
          Enable the TI Quad-SPI (QSPI) driver for DRA7xx and AM43xx evms.
          This driver support spi flash single, quad and memory reads.
 
+config UNIPHIER_SPI
+       bool "Socionext UniPhier SPI driver"
+       depends on ARCH_UNIPHIER
+       help
+         Enable the Socionext UniPhier SPI driver. This driver can
+         be used to access SPI chips on platforms embedding this
+         UniPhier IP core.
+
 config XILINX_SPI
        bool "Xilinx SPI driver"
        help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 3f9f2fa..55605d9 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -58,6 +58,7 @@ obj-$(CONFIG_TEGRA114_SPI) += tegra114_spi.o
 obj-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
 obj-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
 obj-$(CONFIG_TEGRA210_QSPI) += tegra210_qspi.o
+obj-$(CONFIG_UNIPHIER_SPI) += uniphier_spi.o
 obj-$(CONFIG_XILINX_SPI) += xilinx_spi.o
 obj-$(CONFIG_ZYNQ_SPI) += zynq_spi.o
 obj-$(CONFIG_ZYNQ_QSPI) += zynq_qspi.o
diff --git a/drivers/spi/uniphier_spi.c b/drivers/spi/uniphier_spi.c
new file mode 100644
index 0000000..ef02d07
--- /dev/null
+++ b/drivers/spi/uniphier_spi.c
@@ -0,0 +1,413 @@
+// 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,
+};
-- 
2.7.4

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