[U-Boot] [PATCH v6 04/11] dm: spi: add BCM63xx SPI driver

Álvaro Fernández Rojas
2018-01-02T19:01:04Z

This driver is a simplified version of linux/drivers/spi/spi-bcm63xx.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>
---
v6: Introduce changes suggested by Jagan Teki:
- Use cmd instead of val to avoid confusions.
- Switch to wait_for_bit instead of infinite loop.
v5: Introduce changes suggested by Jagan Teki:
- Use long structure instead of a custom bmips_spi_hw structure.
- Define constants for each SPI core.
v4: Introduce changes suggested by Jagan Teki:
- Add data for each HW controller instead of having two separate configs.
- Also check clock and reset returns as suggested by Simon Glass for HSSPI.
v3: rename BCM6338 SPI driver to BCM6348
switch to devfdt_get_addr_size_index()
v2: no changes

drivers/spi/Kconfig | 8 +
drivers/spi/Makefile | 1 +
drivers/spi/bcm63xx_spi.c | 433 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 442 insertions(+)
create mode 100644 drivers/spi/bcm63xx_spi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 494639fb01..ebc71c2e42 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -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_SPI
+ bool "BCM6348 SPI driver"
+ depends on ARCH_BMIPS
+ help
+ Enable the BCM6348/BCM6358 SPI driver. This driver can be used to
+ access the SPI NOR flash on platforms embedding these Broadcom
+ SPI cores.
+
config CADENCE_QSPI
bool "Cadence QSPI driver"
help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index e3184db67f..5770b3f7cc 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -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_SPI) += bcm63xx_spi.o
obj-$(CONFIG_CADENCE_QSPI) += cadence_qspi.o cadence_qspi_apb.o
obj-$(CONFIG_CF_SPI) += cf_spi.o
obj-$(CONFIG_DAVINCI_SPI) += davinci_spi.o
diff --git a/drivers/spi/bcm63xx_spi.c b/drivers/spi/bcm63xx_spi.c
new file mode 100644
index 0000000000..88257db728
--- /dev/null
+++ b/drivers/spi/bcm63xx_spi.c
@@ -0,0 +1,433 @@
+/*
+ * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
+ *
+ * Derived from linux/drivers/spi/spi-bcm63xx.c:
+ * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
+ * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
+ *
+ * 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;
+
+/* BCM6348 SPI core */
+#define SPI_6348_CLK 0x06
+#define SPI_6348_CMD 0x00
+#define SPI_6348_CTL 0x40
+#define SPI_6348_CTL_SHIFT 6
+#define SPI_6348_FILL 0x07
+#define SPI_6348_IR_MASK 0x04
+#define SPI_6348_IR_STAT 0x02
+#define SPI_6348_RX 0x80
+#define SPI_6348_RX_SIZE 0x3f
+#define SPI_6348_TX 0x41
+#define SPI_6348_TX_SIZE 0x3f
+
+/* BCM6358 SPI core */
+#define SPI_6358_CLK 0x706
+#define SPI_6358_CMD 0x700
+#define SPI_6358_CTL 0x000
+#define SPI_6358_CTL_SHIFT 14
+#define SPI_6358_FILL 0x707
+#define SPI_6358_IR_MASK 0x702
+#define SPI_6358_IR_STAT 0x704
+#define SPI_6358_RX 0x400
+#define SPI_6358_RX_SIZE 0x220
+#define SPI_6358_TX 0x002
+#define SPI_6358_TX_SIZE 0x21e
+
+/* SPI Clock register */
+#define SPI_CLK_SHIFT 0
+#define SPI_CLK_20MHZ (0 << SPI_CLK_SHIFT)
+#define SPI_CLK_0_391MHZ (1 << SPI_CLK_SHIFT)
+#define SPI_CLK_0_781MHZ (2 << SPI_CLK_SHIFT)
+#define SPI_CLK_1_563MHZ (3 << SPI_CLK_SHIFT)
+#define SPI_CLK_3_125MHZ (4 << SPI_CLK_SHIFT)
+#define SPI_CLK_6_250MHZ (5 << SPI_CLK_SHIFT)
+#define SPI_CLK_12_50MHZ (6 << SPI_CLK_SHIFT)
+#define SPI_CLK_25MHZ (7 << SPI_CLK_SHIFT)
+#define SPI_CLK_MASK (7 << SPI_CLK_SHIFT)
+#define SPI_CLK_SSOFF_SHIFT 3
+#define SPI_CLK_SSOFF_2 (2 << SPI_CLK_SSOFF_SHIFT)
+#define SPI_CLK_SSOFF_MASK (7 << SPI_CLK_SSOFF_SHIFT)
+#define SPI_CLK_BSWAP_SHIFT 7
+#define SPI_CLK_BSWAP_MASK (1 << SPI_CLK_BSWAP_SHIFT)
+
+/* SPI Command register */
+#define SPI_CMD_OP_SHIFT 0
+#define SPI_CMD_OP_START (0x3 << SPI_CMD_OP_SHIFT)
+#define SPI_CMD_SLAVE_SHIFT 4
+#define SPI_CMD_SLAVE_MASK (0xf << SPI_CMD_SLAVE_SHIFT)
+#define SPI_CMD_PREPEND_SHIFT 8
+#define SPI_CMD_PREPEND_BYTES 0xf
+#define SPI_CMD_3WIRE_SHIFT 12
+#define SPI_CMD_3WIRE_MASK (1 << SPI_CMD_3WIRE_SHIFT)
+
+/* SPI Control register */
+#define SPI_CTL_TYPE_FD_RW 0
+#define SPI_CTL_TYPE_HD_W 1
+#define SPI_CTL_TYPE_HD_R 2
+
+/* SPI Interrupt registers */
+#define SPI_IR_DONE_SHIFT 0
+#define SPI_IR_DONE_MASK (1 << SPI_IR_DONE_SHIFT)
+#define SPI_IR_RXOVER_SHIFT 1
+#define SPI_IR_RXOVER_MASK (1 << SPI_IR_RXOVER_SHIFT)
+#define SPI_IR_TXUNDER_SHIFT 2
+#define SPI_IR_TXUNDER_MASK (1 << SPI_IR_TXUNDER_SHIFT)
+#define SPI_IR_TXOVER_SHIFT 3
+#define SPI_IR_TXOVER_MASK (1 << SPI_IR_TXOVER_SHIFT)
+#define SPI_IR_RXUNDER_SHIFT 4
+#define SPI_IR_RXUNDER_MASK (1 << SPI_IR_RXUNDER_SHIFT)
+#define SPI_IR_CLEAR_MASK (SPI_IR_DONE_MASK |\
+ SPI_IR_RXOVER_MASK |\
+ SPI_IR_TXUNDER_MASK |\
+ SPI_IR_TXOVER_MASK |\
+ SPI_IR_RXUNDER_MASK)
+
+enum bcm63xx_regs_spi {
+ SPI_CLK,
+ SPI_CMD,
+ SPI_CTL,
+ SPI_CTL_SHIFT,
+ SPI_FILL,
+ SPI_IR_MASK,
+ SPI_IR_STAT,
+ SPI_RX,
+ SPI_RX_SIZE,
+ SPI_TX,
+ SPI_TX_SIZE,
+};
+
+struct bcm63xx_spi_priv {
+ const unsigned long *regs;
+ void __iomem *base;
+ size_t tx_bytes;
+ uint8_t num_cs;
+};
+
+#define SPI_CLK_CNT 8
+static const unsigned bcm63xx_spi_freq_table[SPI_CLK_CNT][2] = {
+ { 25000000, SPI_CLK_25MHZ },
+ { 20000000, SPI_CLK_20MHZ },
+ { 12500000, SPI_CLK_12_50MHZ },
+ { 6250000, SPI_CLK_6_250MHZ },
+ { 3125000, SPI_CLK_3_125MHZ },
+ { 1563000, SPI_CLK_1_563MHZ },
+ { 781000, SPI_CLK_0_781MHZ },
+ { 391000, SPI_CLK_0_391MHZ }
+};
+
+static int bcm63xx_spi_cs_info(struct udevice *bus, uint cs,
+ struct spi_cs_info *info)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
+
+ if (cs >= priv->num_cs) {
+ printf("no cs %u\n", cs);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int bcm63xx_spi_set_mode(struct udevice *bus, uint mode)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
+ const unsigned long *regs = priv->regs;
+
+ if (mode & SPI_LSB_FIRST)
+ setbits_8(priv->base + regs[SPI_CLK], SPI_CLK_BSWAP_MASK);
+ else
+ clrbits_8(priv->base + regs[SPI_CLK], SPI_CLK_BSWAP_MASK);
+
+ return 0;
+}
+
+static int bcm63xx_spi_set_speed(struct udevice *bus, uint speed)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
+ const unsigned long *regs = priv->regs;
+ uint8_t clk_cfg;
+ int i;
+
+ /* default to lowest clock configuration */
+ clk_cfg = SPI_CLK_0_391MHZ;
+
+ /* find the closest clock configuration */
+ for (i = 0; i < SPI_CLK_CNT; i++) {
+ if (speed >= bcm63xx_spi_freq_table[i][0]) {
+ clk_cfg = bcm63xx_spi_freq_table[i][1];
+ break;
+ }
+ }
+
+ /* write clock configuration */
+ clrsetbits_8(priv->base + regs[SPI_CLK],
+ SPI_CLK_SSOFF_MASK | SPI_CLK_MASK,
+ clk_cfg | SPI_CLK_SSOFF_2);
+
+ return 0;
+}
+
+/*
+ * BCM63xx SPI driver doesn't allow keeping CS active between transfers since
+ * they are HW controlled.
+ * 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.
+ *
+ * This implementation takes advantage of the prepend mechanism and combines
+ * multiple transfers into a single one where possible (single/multiple write
+ * transfer(s) followed by a final read/write transfer).
+ * However, it's not possible to buffer reads, which means that read transfers
+ * should always be done as the final ones.
+ * On the other hand, take into account that combining write transfers into
+ * a single one is just buffering and doesn't require prepend mechanism.
+ */
+static int bcm63xx_spi_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
+ const unsigned long *regs = priv->regs;
+ size_t data_bytes = bitlen / 8;
+
+ if (flags & SPI_XFER_BEGIN) {
+ /* clear prepends */
+ priv->tx_bytes = 0;
+
+ /* initialize hardware */
+ writeb_be(0, priv->base + regs[SPI_IR_MASK]);
+ }
+
+ if (din) {
+ /* buffering reads not possible since cs is hw controlled */
+ if (!(flags & SPI_XFER_END)) {
+ printf("unable to buffer reads\n");
+ return -EINVAL;
+ }
+
+ /* check rx size */
+ if (data_bytes > regs[SPI_RX_SIZE]) {
+ printf("max rx bytes exceeded\n");
+ return -EMSGSIZE;
+ }
+ }
+
+ if (dout) {
+ /* check tx size */
+ if (priv->tx_bytes + data_bytes > regs[SPI_TX_SIZE]) {
+ printf("max tx bytes exceeded\n");
+ return -EMSGSIZE;
+ }
+
+ /* copy tx data */
+ memcpy_toio(priv->base + regs[SPI_TX] + priv->tx_bytes,
+ dout, data_bytes);
+ priv->tx_bytes += data_bytes;
+ }
+
+ if (flags & SPI_XFER_END) {
+ struct dm_spi_slave_platdata *plat =
+ dev_get_parent_platdata(dev);
+ uint16_t val, cmd;
+ int ret;
+
+ /* determine control config */
+ if (dout && !din) {
+ /* buffered write transfers */
+ val = priv->tx_bytes;
+ val |= (SPI_CTL_TYPE_HD_W << regs[SPI_CTL_SHIFT]);
+ priv->tx_bytes = 0;
+ } else {
+ if (dout && din && (flags & SPI_XFER_ONCE)) {
+ /* full duplex read/write */
+ val = data_bytes;
+ val |= (SPI_CTL_TYPE_FD_RW <<
+ regs[SPI_CTL_SHIFT]);
+ priv->tx_bytes = 0;
+ } else {
+ /* prepended write transfer */
+ val = data_bytes;
+ val |= (SPI_CTL_TYPE_HD_R <<
+ regs[SPI_CTL_SHIFT]);
+ if (priv->tx_bytes > SPI_CMD_PREPEND_BYTES) {
+ printf("max prepend bytes exceeded\n");
+ return -EMSGSIZE;
+ }
+ }
+ }
+
+ if (regs[SPI_CTL_SHIFT] >= 8)
+ writew_be(val, priv->base + regs[SPI_CTL]);
+ else
+ writeb_be(val, priv->base + regs[SPI_CTL]);
+
+ /* clear interrupts */
+ writeb_be(SPI_IR_CLEAR_MASK, priv->base + regs[SPI_IR_STAT]);
+
+ /* issue the transfer */
+ cmd = SPI_CMD_OP_START;
+ cmd |= (plat->cs << SPI_CMD_SLAVE_SHIFT) & SPI_CMD_SLAVE_MASK;
+ cmd |= (priv->tx_bytes << SPI_CMD_PREPEND_SHIFT);
+ if (plat->mode & SPI_3WIRE)
+ cmd |= SPI_CMD_3WIRE_MASK;
+ writew_be(cmd, priv->base + regs[SPI_CMD]);
+
+ /* enable interrupts */
+ writeb_be(SPI_IR_DONE_MASK, priv->base + regs[SPI_IR_MASK]);
+
+ ret = wait_for_bit_8(__func__, priv->base + regs[SPI_IR_STAT],
+ SPI_IR_DONE_MASK, true, 1000, false);
+ if (ret) {
+ printf("interrupt timeout\n");
+ return ret;
+ }
+
+ /* copy rx data */
+ if (din)
+ memcpy_fromio(din, priv->base + regs[SPI_RX],
+ data_bytes);
+ }
+
+ return 0;
+}
+
+static const struct dm_spi_ops bcm63xx_spi_ops = {
+ .cs_info = bcm63xx_spi_cs_info,
+ .set_mode = bcm63xx_spi_set_mode,
+ .set_speed = bcm63xx_spi_set_speed,
+ .xfer = bcm63xx_spi_xfer,
+};
+
+static const unsigned long bcm6348_spi_regs[] = {
+ [SPI_CLK] = SPI_6348_CLK,
+ [SPI_CMD] = SPI_6348_CMD,
+ [SPI_CTL] = SPI_6348_CTL,
+ [SPI_CTL_SHIFT] = SPI_6348_CTL_SHIFT,
+ [SPI_FILL] = SPI_6348_FILL,
+ [SPI_IR_MASK] = SPI_6348_IR_MASK,
+ [SPI_IR_STAT] = SPI_6348_IR_STAT,
+ [SPI_RX] = SPI_6348_RX,
+ [SPI_RX_SIZE] = SPI_6348_RX_SIZE,
+ [SPI_TX] = SPI_6348_TX,
+ [SPI_TX_SIZE] = SPI_6348_TX_SIZE,
+};
+
+static const unsigned long bcm6358_spi_regs[] = {
+ [SPI_CLK] = SPI_6358_CLK,
+ [SPI_CMD] = SPI_6358_CMD,
+ [SPI_CTL] = SPI_6358_CTL,
+ [SPI_CTL_SHIFT] = SPI_6358_CTL_SHIFT,
+ [SPI_FILL] = SPI_6358_FILL,
+ [SPI_IR_MASK] = SPI_6358_IR_MASK,
+ [SPI_IR_STAT] = SPI_6358_IR_STAT,
+ [SPI_RX] = SPI_6358_RX,
+ [SPI_RX_SIZE] = SPI_6358_RX_SIZE,
+ [SPI_TX] = SPI_6358_TX,
+ [SPI_TX_SIZE] = SPI_6358_TX_SIZE,
+};
+
+static const struct udevice_id bcm63xx_spi_ids[] = {
+ {
+ .compatible = "brcm,bcm6348-spi",
+ .data = (ulong)&bcm6348_spi_regs,
+ }, {
+ .compatible = "brcm,bcm6358-spi",
+ .data = (ulong)&bcm6358_spi_regs,
+ }, { /* sentinel */ }
+};
+
+static int bcm63xx_spi_child_pre_probe(struct udevice *dev)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
+ const unsigned long *regs = priv->regs;
+ struct spi_slave *slave = dev_get_parent_priv(dev);
+ 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;
+ }
+
+ /* max read/write sizes */
+ slave->max_read_size = regs[SPI_RX_SIZE];
+ slave->max_write_size = regs[SPI_TX_SIZE];
+
+ return 0;
+}
+
+static int bcm63xx_spi_probe(struct udevice *dev)
+{
+ struct bcm63xx_spi_priv *priv = dev_get_priv(dev);
+ const unsigned long *regs =
+ (const unsigned long *)dev_get_driver_data(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 = regs;
+ priv->base = 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_index(dev, 0, &clk);
+ if (ret < 0)
+ return ret;
+
+ ret = clk_enable(&clk);
+ if (ret < 0)
+ return ret;
+
+ 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 */
+ writeb_be(0, priv->base + regs[SPI_IR_MASK]);
+
+ /* set fill register */
+ writeb_be(0xff, priv->base + regs[SPI_FILL]);
+
+ return 0;
+}
+
+U_BOOT_DRIVER(bcm63xx_spi) = {
+ .name = "bcm63xx_spi",
+ .id = UCLASS_SPI,
+ .of_match = bcm63xx_spi_ids,
+ .ops = &bcm63xx_spi_ops,
+ .priv_auto_alloc_size = sizeof(struct bcm63xx_spi_priv),
+ .child_pre_probe = bcm63xx_spi_child_pre_probe,
+ .probe = bcm63xx_spi_probe,
+};
--
2.11.0