drivers: spi: add spi support for QCA/Atheros ath79 SOCs

This patch add a compatible spi driver for ath79 series SOC.

Signed-off-by: Wills Wang <wills.wang@live.com>
Reviewed-by: Thomas Chou <thomas@wytron.com.tw>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

diff --git a/doc/device-tree-bindings/spi/spi-ath79.txt b/doc/device-tree-bindings/spi/spi-ath79.txt
new file mode 100644 (file)
index 0000000..3fd9d67
--- /dev/null
+++ b/doc/device-tree-bindings/spi/spi-ath79.txt
@@ -0,0 +1,19 @@
+Binding for Qualcomm Atheros AR7xxx/AR9xxx SPI controller
+
+Required properties:
+- compatible: has to be "qca,<soc-type>-spi", "qca,ar7100-spi" as fallback.
+- reg: Base address and size of the controllers memory area
+- #address-cells: <1>, as required by generic SPI binding.
+- #size-cells: <0>, also as required by generic SPI binding.
+
+Child nodes as per the generic SPI binding.
+
+Example:
+
+       spi@1f000000 {
+               compatible = "qca,ar9132-spi", "qca,ar7100-spi";
+               reg = <0x1f000000 0x10>;
+
+               #address-cells = <1>;
+               #size-cells = <0>;
+       };

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index f0258f84afeb64a0ac8c1e7ecbe9ee52fc99c0ea..b7fd8e53a2f62d6cd1f7aefa91f82e89c7fe5aea 100644 (file)
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -23,6 +23,15 @@ config ALTERA_SPI
          IP core. Please find details on the "Embedded Peripherals IP
          User Guide" of Altera.
 
+config ATH79_SPI
+       bool "Atheros SPI driver"
+       depends on ARCH_ATH79
+       help
+         Enable the Atheros ar7xxx/ar9xxx SoC SPI driver, it was used
+         to access SPI NOR flash and other SPI peripherals. This driver
+         uses driver model and requires a device tree binding to operate.
+         please refer to doc/device-tree-bindings/spi/spi-ath79.txt.
+
 config CADENCE_QSPI
        bool "Cadence QSPI driver"
        help

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 3eca7456d6a6bf865726fe27216365f30e6c1327..7fb2926e78135129939dbad3e789a8d8a0d67ed9 100644 (file)
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -17,6 +17,7 @@ endif
 
 obj-$(CONFIG_ALTERA_SPI) += altera_spi.o
 obj-$(CONFIG_ARMADA100_SPI) += armada100_spi.o
+obj-$(CONFIG_ATH79_SPI) += ath79_spi.o
 obj-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o
 obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o
 obj-$(CONFIG_BFIN_SPI) += bfin_spi.o

diff --git a/drivers/spi/ath79_spi.c b/drivers/spi/ath79_spi.c
new file mode 100644 (file)
index 0000000..0c1022d
--- /dev/null
+++ b/drivers/spi/ath79_spi.c
@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) 2015-2016 Wills Wang <wills.wang@live.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <spi.h>
+#include <dm.h>
+#include <div64.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <asm/addrspace.h>
+#include <asm/types.h>
+#include <dm/pinctrl.h>
+#include <mach/ar71xx_regs.h>
+
+/* CLOCK_DIVIDER = 3 (SPI clock = 200 / 8 ~ 25 MHz) */
+#define ATH79_SPI_CLK_DIV(x)           (((x) >> 1) - 1)
+#define ATH79_SPI_RRW_DELAY_FACTOR     12000
+#define ATH79_SPI_MHZ                  (1000 * 1000)
+
+struct ath79_spi_priv {
+       void __iomem *regs;
+       u32 rrw_delay;
+};
+
+static void spi_cs_activate(struct udevice *dev)
+{
+       struct udevice *bus = dev_get_parent(dev);
+       struct ath79_spi_priv *priv = dev_get_priv(bus);
+
+       writel(AR71XX_SPI_FS_GPIO, priv->regs + AR71XX_SPI_REG_FS);
+       writel(AR71XX_SPI_IOC_CS_ALL, priv->regs + AR71XX_SPI_REG_IOC);
+}
+
+static void spi_cs_deactivate(struct udevice *dev)
+{
+       struct udevice *bus = dev_get_parent(dev);
+       struct ath79_spi_priv *priv = dev_get_priv(bus);
+
+       writel(AR71XX_SPI_IOC_CS_ALL, priv->regs + AR71XX_SPI_REG_IOC);
+       writel(0, priv->regs + AR71XX_SPI_REG_FS);
+}
+
+static int ath79_spi_claim_bus(struct udevice *dev)
+{
+       return 0;
+}
+
+static int ath79_spi_release_bus(struct udevice *dev)
+{
+       return 0;
+}
+
+static int ath79_spi_xfer(struct udevice *dev, unsigned int bitlen,
+               const void *dout, void *din, unsigned long flags)
+{
+       struct udevice *bus = dev_get_parent(dev);
+       struct ath79_spi_priv *priv = dev_get_priv(bus);
+       struct dm_spi_slave_platdata *slave = dev_get_parent_platdata(dev);
+       u8 *rx = din;
+       const u8 *tx = dout;
+       u8 curbyte, curbitlen, restbits;
+       u32 bytes = bitlen / 8;
+       u32 out, in;
+       u64 tick;
+
+       if (flags & SPI_XFER_BEGIN)
+               spi_cs_activate(dev);
+
+       restbits = (bitlen % 8);
+       if (restbits)
+               bytes++;
+
+       out = AR71XX_SPI_IOC_CS_ALL & ~(AR71XX_SPI_IOC_CS(slave->cs));
+       while (bytes > 0) {
+               bytes--;
+               curbyte = 0;
+               if (tx)
+                       curbyte = *tx++;
+
+               if (restbits && !bytes) {
+                       curbitlen = restbits;
+                       curbyte <<= 8 - restbits;
+               } else {
+                       curbitlen = 8;
+               }
+
+               for (curbyte <<= (8 - curbitlen); curbitlen; curbitlen--) {
+                       if (curbyte & 0x80)
+                               out |= AR71XX_SPI_IOC_DO;
+                       else
+                               out &= ~(AR71XX_SPI_IOC_DO);
+
+                       writel(out, priv->regs + AR71XX_SPI_REG_IOC);
+
+                       /* delay for low level */
+                       if (priv->rrw_delay) {
+                               tick = get_ticks() + priv->rrw_delay;
+                               while (get_ticks() < tick)
+                                       /*NOP*/;
+                       }
+
+                       writel(out | AR71XX_SPI_IOC_CLK,
+                              priv->regs + AR71XX_SPI_REG_IOC);
+
+                       /* delay for high level */
+                       if (priv->rrw_delay) {
+                               tick = get_ticks() + priv->rrw_delay;
+                               while (get_ticks() < tick)
+                                       /*NOP*/;
+                       }
+
+                       curbyte <<= 1;
+               }
+
+               if (!bytes)
+                       writel(out, priv->regs + AR71XX_SPI_REG_IOC);
+
+               in = readl(priv->regs + AR71XX_SPI_REG_RDS);
+               if (rx) {
+                       if (restbits && !bytes)
+                               *rx++ = (in << (8 - restbits));
+                       else
+                               *rx++ = in;
+               }
+       }
+
+       if (flags & SPI_XFER_END)
+               spi_cs_deactivate(dev);
+
+       return 0;
+}
+
+
+static int ath79_spi_set_speed(struct udevice *bus, uint speed)
+{
+       struct ath79_spi_priv *priv = dev_get_priv(bus);
+       u32 val, div = 0;
+       u64 time;
+
+       if (speed)
+               div = get_bus_freq(0) / speed;
+
+       if (div > 63)
+               div = 63;
+
+       if (div < 5)
+               div = 5;
+
+       /* calculate delay */
+       time = get_tbclk();
+       do_div(time, speed / 2);
+       val = get_bus_freq(0) / ATH79_SPI_MHZ;
+       val = ATH79_SPI_RRW_DELAY_FACTOR / val;
+       if (time > val)
+               priv->rrw_delay = time - val + 1;
+       else
+               priv->rrw_delay = 0;
+
+       writel(AR71XX_SPI_FS_GPIO, priv->regs + AR71XX_SPI_REG_FS);
+       clrsetbits_be32(priv->regs + AR71XX_SPI_REG_CTRL,
+                       AR71XX_SPI_CTRL_DIV_MASK,
+                       ATH79_SPI_CLK_DIV(div));
+       writel(0, priv->regs + AR71XX_SPI_REG_FS);
+       return 0;
+}
+
+static int ath79_spi_set_mode(struct udevice *bus, uint mode)
+{
+       return 0;
+}
+
+static int ath79_spi_probe(struct udevice *bus)
+{
+       struct ath79_spi_priv *priv = dev_get_priv(bus);
+       struct udevice *pinctrl;
+       fdt_addr_t addr;
+       int ret;
+
+       ret = uclass_get_device(UCLASS_PINCTRL, 0, &pinctrl);
+       if (ret)
+               return ret;
+       ret = pinctrl_get_periph_id(pinctrl, bus);
+       if (ret < 0)
+               return ret;
+       ret = pinctrl_request(pinctrl, ret, 0);
+       if (ret < 0)
+               return ret;
+
+       addr = dev_get_addr(bus);
+       if (addr == FDT_ADDR_T_NONE)
+               return -EINVAL;
+
+       priv->regs = map_physmem(addr,
+                                AR71XX_SPI_SIZE,
+                                MAP_NOCACHE);
+
+       /* Init SPI Hardware, disable remap, set clock */
+       writel(AR71XX_SPI_FS_GPIO, priv->regs + AR71XX_SPI_REG_FS);
+       writel(AR71XX_SPI_CTRL_RD | ATH79_SPI_CLK_DIV(8),
+              priv->regs + AR71XX_SPI_REG_CTRL);
+       writel(0, priv->regs + AR71XX_SPI_REG_FS);
+
+       return 0;
+}
+
+static int ath79_cs_info(struct udevice *bus, uint cs,
+                          struct spi_cs_info *info)
+{
+       /* Always allow activity on CS 0/1/2 */
+       if (cs >= 3)
+               return -ENODEV;
+
+       return 0;
+}
+
+static const struct dm_spi_ops ath79_spi_ops = {
+       .claim_bus  = ath79_spi_claim_bus,
+       .release_bus    = ath79_spi_release_bus,
+       .xfer       = ath79_spi_xfer,
+       .set_speed  = ath79_spi_set_speed,
+       .set_mode   = ath79_spi_set_mode,
+       .cs_info    = ath79_cs_info,
+};
+
+static const struct udevice_id ath79_spi_ids[] = {
+       { .compatible = "qca,ar7100-spi" },
+       {}
+};
+
+U_BOOT_DRIVER(ath79_spi) = {
+       .name   = "ath79_spi",
+       .id = UCLASS_SPI,
+       .of_match = ath79_spi_ids,
+       .ops    = &ath79_spi_ops,
+       .priv_auto_alloc_size = sizeof(struct ath79_spi_priv),
+       .probe  = ath79_spi_probe,
+};