dm: spi: add BCM63xx HSSPI driver
authorÁlvaro Fernández Rojas <noltari@gmail.com>
Sat, 20 Jan 2018 01:13:38 +0000 (02:13 +0100)
committerJagan Teki <jagan@amarulasolutions.com>
Wed, 24 Jan 2018 06:34:06 +0000 (12:04 +0530)
This driver is a simplified version of linux/drivers/spi/spi-bcm63xx-hsspi.c

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
drivers/spi/Kconfig
drivers/spi/Makefile
drivers/spi/bcm63xx_hsspi.c [new file with mode: 0644]

index ebc71c2e42b964b46d3c3a652a1efe71deb596de..28ddcf85a36f177d31c893a3de8c6d929d066bfa 100644 (file)
@@ -40,6 +40,14 @@ config ATMEL_SPI
          many AT91 (ARM) chips. This driver can be used to access
          the SPI Flash, such as AT25DF321.
 
+config BCM63XX_HSSPI
+       bool "BCM63XX HSSPI driver"
+       depends on ARCH_BMIPS
+       help
+         Enable the BCM6328 HSSPI driver. This driver can be used to
+         access the SPI NOR flash on platforms embedding this Broadcom
+         SPI core.
+
 config BCM63XX_SPI
        bool "BCM6348 SPI driver"
        depends on ARCH_BMIPS
index 5770b3f7ccce974bdbd2475092d1f88df42ee35b..4b6000fd9a04f7e6c873cbe4b3100d04313f2f4d 100644 (file)
@@ -18,6 +18,7 @@ endif
 obj-$(CONFIG_ALTERA_SPI) += altera_spi.o
 obj-$(CONFIG_ATH79_SPI) += ath79_spi.o
 obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o
+obj-$(CONFIG_BCM63XX_HSSPI) += bcm63xx_hsspi.o
 obj-$(CONFIG_BCM63XX_SPI) += bcm63xx_spi.o
 obj-$(CONFIG_CADENCE_QSPI) += cadence_qspi.o cadence_qspi_apb.o
 obj-$(CONFIG_CF_SPI) += cf_spi.o
diff --git a/drivers/spi/bcm63xx_hsspi.c b/drivers/spi/bcm63xx_hsspi.c
new file mode 100644 (file)
index 0000000..3393166
--- /dev/null
@@ -0,0 +1,414 @@
+/*
+ * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
+ *
+ * Derived from linux/drivers/spi/spi-bcm63xx-hsspi.c:
+ *     Copyright (C) 2000-2010 Broadcom Corporation
+ *     Copyright (C) 2012-2013 Jonas Gorski <jogo@openwrt.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <spi.h>
+#include <reset.h>
+#include <wait_bit.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define HSSPI_PP                       0
+
+#define SPI_MAX_SYNC_CLOCK             30000000
+
+/* SPI Control register */
+#define SPI_CTL_REG                    0x000
+#define SPI_CTL_CS_POL_SHIFT           0
+#define SPI_CTL_CS_POL_MASK            (0xff << SPI_CTL_CS_POL_SHIFT)
+#define SPI_CTL_CLK_GATE_SHIFT         16
+#define SPI_CTL_CLK_GATE_MASK          (1 << SPI_CTL_CLK_GATE_SHIFT)
+#define SPI_CTL_CLK_POL_SHIFT          17
+#define SPI_CTL_CLK_POL_MASK           (1 << SPI_CTL_CLK_POL_SHIFT)
+
+/* SPI Interrupts registers */
+#define SPI_IR_STAT_REG                        0x008
+#define SPI_IR_ST_MASK_REG             0x00c
+#define SPI_IR_MASK_REG                        0x010
+
+#define SPI_IR_CLEAR_ALL               0xff001f1f
+
+/* SPI Ping-Pong Command registers */
+#define SPI_CMD_REG                    (0x080 + (0x40 * (HSSPI_PP)) + 0x00)
+#define SPI_CMD_OP_SHIFT               0
+#define SPI_CMD_OP_START               (0x1 << SPI_CMD_OP_SHIFT)
+#define SPI_CMD_PFL_SHIFT              8
+#define SPI_CMD_PFL_MASK               (0x7 << SPI_CMD_PFL_SHIFT)
+#define SPI_CMD_SLAVE_SHIFT            12
+#define SPI_CMD_SLAVE_MASK             (0x7 << SPI_CMD_SLAVE_SHIFT)
+
+/* SPI Ping-Pong Status registers */
+#define SPI_STAT_REG                   (0x080 + (0x40 * (HSSPI_PP)) + 0x04)
+#define SPI_STAT_SRCBUSY_SHIFT         1
+#define SPI_STAT_SRCBUSY_MASK          (1 << SPI_STAT_SRCBUSY_SHIFT)
+
+/* SPI Profile Clock registers */
+#define SPI_PFL_CLK_REG(x)             (0x100 + (0x20 * (x)) + 0x00)
+#define SPI_PFL_CLK_FREQ_SHIFT         0
+#define SPI_PFL_CLK_FREQ_MASK          (0x3fff << SPI_PFL_CLK_FREQ_SHIFT)
+#define SPI_PFL_CLK_RSTLOOP_SHIFT      15
+#define SPI_PFL_CLK_RSTLOOP_MASK       (1 << SPI_PFL_CLK_RSTLOOP_SHIFT)
+
+/* SPI Profile Signal registers */
+#define SPI_PFL_SIG_REG(x)             (0x100 + (0x20 * (x)) + 0x04)
+#define SPI_PFL_SIG_LATCHRIS_SHIFT     12
+#define SPI_PFL_SIG_LATCHRIS_MASK      (1 << SPI_PFL_SIG_LATCHRIS_SHIFT)
+#define SPI_PFL_SIG_LAUNCHRIS_SHIFT    13
+#define SPI_PFL_SIG_LAUNCHRIS_MASK     (1 << SPI_PFL_SIG_LAUNCHRIS_SHIFT)
+#define SPI_PFL_SIG_ASYNCIN_SHIFT      16
+#define SPI_PFL_SIG_ASYNCIN_MASK       (1 << SPI_PFL_SIG_ASYNCIN_SHIFT)
+
+/* SPI Profile Mode registers */
+#define SPI_PFL_MODE_REG(x)            (0x100 + (0x20 * (x)) + 0x08)
+#define SPI_PFL_MODE_FILL_SHIFT                0
+#define SPI_PFL_MODE_FILL_MASK         (0xff << SPI_PFL_MODE_FILL_SHIFT)
+#define SPI_PFL_MODE_MDRDSZ_SHIFT      16
+#define SPI_PFL_MODE_MDRDSZ_MASK       (1 << SPI_PFL_MODE_MDRDSZ_SHIFT)
+#define SPI_PFL_MODE_MDWRSZ_SHIFT      18
+#define SPI_PFL_MODE_MDWRSZ_MASK       (1 << SPI_PFL_MODE_MDWRSZ_SHIFT)
+#define SPI_PFL_MODE_3WIRE_SHIFT       20
+#define SPI_PFL_MODE_3WIRE_MASK                (1 << SPI_PFL_MODE_3WIRE_SHIFT)
+
+/* SPI Ping-Pong FIFO registers */
+#define HSSPI_FIFO_SIZE                        0x200
+#define HSSPI_FIFO_BASE                        (0x200 + \
+                                        (HSSPI_FIFO_SIZE * HSSPI_PP))
+
+/* SPI Ping-Pong FIFO OP register */
+#define HSSPI_FIFO_OP_SIZE             0x2
+#define HSSPI_FIFO_OP_REG              (HSSPI_FIFO_BASE + 0x00)
+#define HSSPI_FIFO_OP_BYTES_SHIFT      0
+#define HSSPI_FIFO_OP_BYTES_MASK       (0x3ff << HSSPI_FIFO_OP_BYTES_SHIFT)
+#define HSSPI_FIFO_OP_MBIT_SHIFT       11
+#define HSSPI_FIFO_OP_MBIT_MASK                (1 << HSSPI_FIFO_OP_MBIT_SHIFT)
+#define HSSPI_FIFO_OP_CODE_SHIFT       13
+#define HSSPI_FIFO_OP_READ_WRITE       (1 << HSSPI_FIFO_OP_CODE_SHIFT)
+#define HSSPI_FIFO_OP_CODE_W           (2 << HSSPI_FIFO_OP_CODE_SHIFT)
+#define HSSPI_FIFO_OP_CODE_R           (3 << HSSPI_FIFO_OP_CODE_SHIFT)
+
+struct bcm63xx_hsspi_priv {
+       void __iomem *regs;
+       ulong clk_rate;
+       uint8_t num_cs;
+       uint8_t cs_pols;
+       uint speed;
+};
+
+static int bcm63xx_hsspi_cs_info(struct udevice *bus, uint cs,
+                          struct spi_cs_info *info)
+{
+       struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
+
+       if (cs >= priv->num_cs) {
+               printf("no cs %u\n", cs);
+               return -ENODEV;
+       }
+
+       return 0;
+}
+
+static int bcm63xx_hsspi_set_mode(struct udevice *bus, uint mode)
+{
+       struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
+
+       /* clock polarity */
+       if (mode & SPI_CPOL)
+               setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
+       else
+               clrbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
+
+       return 0;
+}
+
+static int bcm63xx_hsspi_set_speed(struct udevice *bus, uint speed)
+{
+       struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
+
+       priv->speed = speed;
+
+       return 0;
+}
+
+static void bcm63xx_hsspi_activate_cs(struct bcm63xx_hsspi_priv *priv,
+                                  struct dm_spi_slave_platdata *plat)
+{
+       uint32_t clr, set;
+
+       /* profile clock */
+       set = DIV_ROUND_UP(priv->clk_rate, priv->speed);
+       set = DIV_ROUND_UP(2048, set);
+       set &= SPI_PFL_CLK_FREQ_MASK;
+       set |= SPI_PFL_CLK_RSTLOOP_MASK;
+       writel_be(set, priv->regs + SPI_PFL_CLK_REG(plat->cs));
+
+       /* profile signal */
+       set = 0;
+       clr = SPI_PFL_SIG_LAUNCHRIS_MASK |
+             SPI_PFL_SIG_LATCHRIS_MASK |
+             SPI_PFL_SIG_ASYNCIN_MASK;
+
+       /* latch/launch config */
+       if (plat->mode & SPI_CPHA)
+               set |= SPI_PFL_SIG_LAUNCHRIS_MASK;
+       else
+               set |= SPI_PFL_SIG_LATCHRIS_MASK;
+
+       /* async clk */
+       if (priv->speed > SPI_MAX_SYNC_CLOCK)
+               set |= SPI_PFL_SIG_ASYNCIN_MASK;
+
+       clrsetbits_be32(priv->regs + SPI_PFL_SIG_REG(plat->cs), clr, set);
+
+       /* global control */
+       set = 0;
+       clr = 0;
+
+       /* invert cs polarity */
+       if (priv->cs_pols & BIT(plat->cs))
+               clr |= BIT(plat->cs);
+       else
+               set |= BIT(plat->cs);
+
+       /* invert dummy cs polarity */
+       if (priv->cs_pols & BIT(!plat->cs))
+               clr |= BIT(!plat->cs);
+       else
+               set |= BIT(!plat->cs);
+
+       clrsetbits_be32(priv->regs + SPI_CTL_REG, clr, set);
+}
+
+static void bcm63xx_hsspi_deactivate_cs(struct bcm63xx_hsspi_priv *priv)
+{
+       /* restore cs polarities */
+       clrsetbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CS_POL_MASK,
+                       priv->cs_pols);
+}
+
+/*
+ * BCM63xx HSSPI driver doesn't allow keeping CS active between transfers
+ * because they are controlled by HW.
+ * However, it provides a mechanism to prepend write transfers prior to read
+ * transfers (with a maximum prepend of 15 bytes), which is usually enough for
+ * SPI-connected flashes since reading requires prepending a write transfer of
+ * 5 bytes. On the other hand it also provides a way to invert each CS
+ * polarity, not only between transfers like the older BCM63xx SPI driver, but
+ * also the rest of the time.
+ *
+ * Instead of using the prepend mechanism, this implementation inverts the
+ * polarity of both the desired CS and another dummy CS when the bus is
+ * claimed. This way, the dummy CS is restored to its inactive value when
+ * transfers are issued and the desired CS is preserved in its active value
+ * all the time. This hack is also used in the upstream linux driver and
+ * allows keeping CS active between trasnfers even if the HW doesn't give
+ * this possibility.
+ */
+static int bcm63xx_hsspi_xfer(struct udevice *dev, unsigned int bitlen,
+               const void *dout, void *din, unsigned long flags)
+{
+       struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
+       struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
+       size_t data_bytes = bitlen / 8;
+       size_t step_size = HSSPI_FIFO_SIZE;
+       uint16_t opcode = 0;
+       uint32_t val;
+       const uint8_t *tx = dout;
+       uint8_t *rx = din;
+
+       if (flags & SPI_XFER_BEGIN)
+               bcm63xx_hsspi_activate_cs(priv, plat);
+
+       /* fifo operation */
+       if (tx && rx)
+               opcode = HSSPI_FIFO_OP_READ_WRITE;
+       else if (rx)
+               opcode = HSSPI_FIFO_OP_CODE_R;
+       else if (tx)
+               opcode = HSSPI_FIFO_OP_CODE_W;
+
+       if (opcode != HSSPI_FIFO_OP_CODE_R)
+               step_size -= HSSPI_FIFO_OP_SIZE;
+
+       /* dual mode */
+       if ((opcode == HSSPI_FIFO_OP_CODE_R && plat->mode == SPI_RX_DUAL) ||
+           (opcode == HSSPI_FIFO_OP_CODE_W && plat->mode == SPI_TX_DUAL))
+               opcode |= HSSPI_FIFO_OP_MBIT_MASK;
+
+       /* profile mode */
+       val = SPI_PFL_MODE_FILL_MASK |
+             SPI_PFL_MODE_MDRDSZ_MASK |
+             SPI_PFL_MODE_MDWRSZ_MASK;
+       if (plat->mode & SPI_3WIRE)
+               val |= SPI_PFL_MODE_3WIRE_MASK;
+       writel_be(val, priv->regs + SPI_PFL_MODE_REG(plat->cs));
+
+       /* transfer loop */
+       while (data_bytes > 0) {
+               size_t curr_step = min(step_size, data_bytes);
+               int ret;
+
+               /* copy tx data */
+               if (tx) {
+                       memcpy_toio(priv->regs + HSSPI_FIFO_BASE +
+                                   HSSPI_FIFO_OP_SIZE, tx, curr_step);
+                       tx += curr_step;
+               }
+
+               /* set fifo operation */
+               writew_be(opcode | (curr_step & HSSPI_FIFO_OP_BYTES_MASK),
+                         priv->regs + HSSPI_FIFO_OP_REG);
+
+               /* issue the transfer */
+               val = SPI_CMD_OP_START;
+               val |= (plat->cs << SPI_CMD_PFL_SHIFT) &
+                      SPI_CMD_PFL_MASK;
+               val |= (!plat->cs << SPI_CMD_SLAVE_SHIFT) &
+                      SPI_CMD_SLAVE_MASK;
+               writel_be(val, priv->regs + SPI_CMD_REG);
+
+               /* wait for completion */
+               ret = wait_for_bit_be32(priv->regs + SPI_STAT_REG,
+                                       SPI_STAT_SRCBUSY_MASK, false,
+                                       1000, false);
+               if (ret) {
+                       printf("interrupt timeout\n");
+                       return ret;
+               }
+
+               /* copy rx data */
+               if (rx) {
+                       memcpy_fromio(rx, priv->regs + HSSPI_FIFO_BASE,
+                                     curr_step);
+                       rx += curr_step;
+               }
+
+               data_bytes -= curr_step;
+       }
+
+       if (flags & SPI_XFER_END)
+               bcm63xx_hsspi_deactivate_cs(priv);
+
+       return 0;
+}
+
+static const struct dm_spi_ops bcm63xx_hsspi_ops = {
+       .cs_info = bcm63xx_hsspi_cs_info,
+       .set_mode = bcm63xx_hsspi_set_mode,
+       .set_speed = bcm63xx_hsspi_set_speed,
+       .xfer = bcm63xx_hsspi_xfer,
+};
+
+static const struct udevice_id bcm63xx_hsspi_ids[] = {
+       { .compatible = "brcm,bcm6328-hsspi", },
+       { /* sentinel */ }
+};
+
+static int bcm63xx_hsspi_child_pre_probe(struct udevice *dev)
+{
+       struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
+       struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
+
+       /* check cs */
+       if (plat->cs >= priv->num_cs) {
+               printf("no cs %u\n", plat->cs);
+               return -ENODEV;
+       }
+
+       /* cs polarity */
+       if (plat->mode & SPI_CS_HIGH)
+               priv->cs_pols |= BIT(plat->cs);
+       else
+               priv->cs_pols &= ~BIT(plat->cs);
+
+       return 0;
+}
+
+static int bcm63xx_hsspi_probe(struct udevice *dev)
+{
+       struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev);
+       struct reset_ctl rst_ctl;
+       struct clk clk;
+       fdt_addr_t addr;
+       fdt_size_t size;
+       int ret;
+
+       addr = devfdt_get_addr_size_index(dev, 0, &size);
+       if (addr == FDT_ADDR_T_NONE)
+               return -EINVAL;
+
+       priv->regs = ioremap(addr, size);
+       priv->num_cs = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
+                                      "num-cs", 8);
+
+       /* enable clock */
+       ret = clk_get_by_name(dev, "hsspi", &clk);
+       if (ret < 0)
+               return ret;
+
+       ret = clk_enable(&clk);
+       if (ret < 0)
+               return ret;
+
+       ret = clk_free(&clk);
+       if (ret < 0)
+               return ret;
+
+       /* get clock rate */
+       ret = clk_get_by_name(dev, "pll", &clk);
+       if (ret < 0)
+               return ret;
+
+       priv->clk_rate = clk_get_rate(&clk);
+
+       ret = clk_free(&clk);
+       if (ret < 0)
+               return ret;
+
+       /* perform reset */
+       ret = reset_get_by_index(dev, 0, &rst_ctl);
+       if (ret < 0)
+               return ret;
+
+       ret = reset_deassert(&rst_ctl);
+       if (ret < 0)
+               return ret;
+
+       ret = reset_free(&rst_ctl);
+       if (ret < 0)
+               return ret;
+
+       /* initialize hardware */
+       writel_be(0, priv->regs + SPI_IR_MASK_REG);
+
+       /* clear pending interrupts */
+       writel_be(SPI_IR_CLEAR_ALL, priv->regs + SPI_IR_STAT_REG);
+
+       /* enable clk gate */
+       setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_GATE_MASK);
+
+       /* read default cs polarities */
+       priv->cs_pols = readl_be(priv->regs + SPI_CTL_REG) &
+                       SPI_CTL_CS_POL_MASK;
+
+       return 0;
+}
+
+U_BOOT_DRIVER(bcm63xx_hsspi) = {
+       .name = "bcm63xx_hsspi",
+       .id = UCLASS_SPI,
+       .of_match = bcm63xx_hsspi_ids,
+       .ops = &bcm63xx_hsspi_ops,
+       .priv_auto_alloc_size = sizeof(struct bcm63xx_hsspi_priv),
+       .child_pre_probe = bcm63xx_hsspi_child_pre_probe,
+       .probe = bcm63xx_hsspi_probe,
+};