arm: sunxi: Allwinner A10 SPI driver
authorStefan Mavrodiev <stefan@olimex.com>
Tue, 6 Feb 2018 13:14:33 +0000 (15:14 +0200)
committerJagan Teki <jagan@amarulasolutions.com>
Fri, 3 Aug 2018 05:44:08 +0000 (11:14 +0530)
Add spi driver for sun4i, sun5i and sun7i SoCs. The driver is
adapted from mailine kernel.

Signed-off-by: Stefan Mavrodiev <stefan@olimex.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
drivers/spi/Kconfig
drivers/spi/Makefile
drivers/spi/sun4i_spi.c [new file with mode: 0644]

index b85fca562899eecc78f853f22ee7579d66cfc068..dcd719ff0ac6416934a6fc132dcadc9fd0b154e3 100644 (file)
@@ -174,6 +174,11 @@ config STM32_QSPI
          used to access the SPI NOR flash chips on platforms embedding
          this ST IP core.
 
+config SUN4I_SPI
+       bool "Allwinner A10 SoCs SPI controller"
+       help
+         SPI driver for Allwinner sun4i, sun5i and sun7i SoCs
+
 config TEGRA114_SPI
        bool "nVidia Tegra114 SPI driver"
        help
index 95b03a29dc05e90445434416847ddb47c3a2276e..728e30c5383c16b1bf39c052da73984b52b2160a 100644 (file)
@@ -44,6 +44,7 @@ obj-$(CONFIG_SANDBOX_SPI) += sandbox_spi.o
 obj-$(CONFIG_SH_SPI) += sh_spi.o
 obj-$(CONFIG_SH_QSPI) += sh_qspi.o
 obj-$(CONFIG_STM32_QSPI) += stm32_qspi.o
+obj-$(CONFIG_SUN4I_SPI) += sun4i_spi.o
 obj-$(CONFIG_TEGRA114_SPI) += tegra114_spi.o
 obj-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
 obj-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
diff --git a/drivers/spi/sun4i_spi.c b/drivers/spi/sun4i_spi.c
new file mode 100644 (file)
index 0000000..b86b5a0
--- /dev/null
@@ -0,0 +1,456 @@
+/*
+ * (C) Copyright 2017 Whitebox Systems / Northend Systems B.V.
+ * S.J.R. van Schaik <stephan@whiteboxsystems.nl>
+ * M.B.W. Wajer <merlijn@whiteboxsystems.nl>
+ *
+ * (C) Copyright 2017 Olimex Ltd..
+ * Stefan Mavrodiev <stefan@olimex.com>
+ *
+ * Based on linux spi driver. Original copyright follows:
+ * linux/drivers/spi/spi-sun4i.c
+ *
+ * Copyright (C) 2012 - 2014 Allwinner Tech
+ * Pan Nan <pannan@allwinnertech.com>
+ *
+ * Copyright (C) 2014 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * SPDX-License-Identifier:    GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <spi.h>
+#include <errno.h>
+#include <fdt_support.h>
+#include <wait_bit.h>
+
+#include <asm/bitops.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+
+#include <asm/arch/clock.h>
+
+#define SUN4I_FIFO_DEPTH       64
+
+#define SUN4I_RXDATA_REG       0x00
+
+#define SUN4I_TXDATA_REG       0x04
+
+#define SUN4I_CTL_REG          0x08
+#define SUN4I_CTL_ENABLE               BIT(0)
+#define SUN4I_CTL_MASTER               BIT(1)
+#define SUN4I_CTL_CPHA                 BIT(2)
+#define SUN4I_CTL_CPOL                 BIT(3)
+#define SUN4I_CTL_CS_ACTIVE_LOW                BIT(4)
+#define SUN4I_CTL_LMTF                 BIT(6)
+#define SUN4I_CTL_TF_RST               BIT(8)
+#define SUN4I_CTL_RF_RST               BIT(9)
+#define SUN4I_CTL_XCH_MASK             0x0400
+#define SUN4I_CTL_XCH                  BIT(10)
+#define SUN4I_CTL_CS_MASK              0x3000
+#define SUN4I_CTL_CS(cs)               (((cs) << 12) & SUN4I_CTL_CS_MASK)
+#define SUN4I_CTL_DHB                  BIT(15)
+#define SUN4I_CTL_CS_MANUAL            BIT(16)
+#define SUN4I_CTL_CS_LEVEL             BIT(17)
+#define SUN4I_CTL_TP                   BIT(18)
+
+#define SUN4I_INT_CTL_REG      0x0c
+#define SUN4I_INT_CTL_RF_F34           BIT(4)
+#define SUN4I_INT_CTL_TF_E34           BIT(12)
+#define SUN4I_INT_CTL_TC               BIT(16)
+
+#define SUN4I_INT_STA_REG      0x10
+
+#define SUN4I_DMA_CTL_REG      0x14
+
+#define SUN4I_WAIT_REG         0x18
+
+#define SUN4I_CLK_CTL_REG      0x1c
+#define SUN4I_CLK_CTL_CDR2_MASK                0xff
+#define SUN4I_CLK_CTL_CDR2(div)                ((div) & SUN4I_CLK_CTL_CDR2_MASK)
+#define SUN4I_CLK_CTL_CDR1_MASK                0xf
+#define SUN4I_CLK_CTL_CDR1(div)                (((div) & SUN4I_CLK_CTL_CDR1_MASK) << 8)
+#define SUN4I_CLK_CTL_DRS              BIT(12)
+
+#define SUN4I_MAX_XFER_SIZE            0xffffff
+
+#define SUN4I_BURST_CNT_REG    0x20
+#define SUN4I_BURST_CNT(cnt)           ((cnt) & SUN4I_MAX_XFER_SIZE)
+
+#define SUN4I_XMIT_CNT_REG     0x24
+#define SUN4I_XMIT_CNT(cnt)            ((cnt) & SUN4I_MAX_XFER_SIZE)
+
+#define SUN4I_FIFO_STA_REG     0x28
+#define SUN4I_FIFO_STA_RF_CNT_MASK     0x7f
+#define SUN4I_FIFO_STA_RF_CNT_BITS     0
+#define SUN4I_FIFO_STA_TF_CNT_MASK     0x7f
+#define SUN4I_FIFO_STA_TF_CNT_BITS     16
+
+#define SUN4I_SPI_MAX_RATE     24000000
+#define SUN4I_SPI_MIN_RATE     3000
+#define SUN4I_SPI_DEFAULT_RATE 1000000
+#define SUN4I_SPI_TIMEOUT_US   1000000
+
+/* sun4i spi register set */
+struct sun4i_spi_regs {
+       u32 rxdata;
+       u32 txdata;
+       u32 ctl;
+       u32 intctl;
+       u32 st;
+       u32 dmactl;
+       u32 wait;
+       u32 cctl;
+       u32 bc;
+       u32 tc;
+       u32 fifo_sta;
+};
+
+struct sun4i_spi_platdata {
+       u32 base_addr;
+       u32 max_hz;
+};
+
+struct sun4i_spi_priv {
+       struct sun4i_spi_regs *regs;
+       u32 freq;
+       u32 mode;
+
+       const u8 *tx_buf;
+       u8 *rx_buf;
+};
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static inline void sun4i_spi_drain_fifo(struct sun4i_spi_priv *priv, int len)
+{
+       u8 byte;
+
+       while (len--) {
+               byte = readb(&priv->regs->rxdata);
+               *priv->rx_buf++ = byte;
+       }
+}
+
+static inline void sun4i_spi_fill_fifo(struct sun4i_spi_priv *priv, int len)
+{
+       u8 byte;
+
+       while (len--) {
+               byte = priv->tx_buf ? *priv->tx_buf++ : 0;
+               writeb(byte, &priv->regs->txdata);
+       }
+}
+
+static void sun4i_spi_set_cs(struct udevice *bus, u8 cs, bool enable)
+{
+       struct sun4i_spi_priv *priv = dev_get_priv(bus);
+       u32 reg;
+
+       reg = readl(&priv->regs->ctl);
+
+       reg &= ~SUN4I_CTL_CS_MASK;
+       reg |= SUN4I_CTL_CS(cs);
+
+       if (enable)
+               reg &= ~SUN4I_CTL_CS_LEVEL;
+       else
+               reg |= SUN4I_CTL_CS_LEVEL;
+
+       writel(reg, &priv->regs->ctl);
+}
+
+static int sun4i_spi_parse_pins(struct udevice *dev)
+{
+       const void *fdt = gd->fdt_blob;
+       const char *pin_name;
+       const fdt32_t *list;
+       u32 phandle;
+       int drive, pull = 0, pin, i;
+       int offset;
+       int size;
+
+       list = fdt_getprop(fdt, dev_of_offset(dev), "pinctrl-0", &size);
+       if (!list) {
+               printf("WARNING: sun4i_spi: cannot find pinctrl-0 node\n");
+               return -EINVAL;
+       }
+
+       while (size) {
+               phandle = fdt32_to_cpu(*list++);
+               size -= sizeof(*list);
+
+               offset = fdt_node_offset_by_phandle(fdt, phandle);
+               if (offset < 0)
+                       return offset;
+
+               drive = fdt_getprop_u32_default_node(fdt, offset, 0,
+                                                    "drive-strength", 0);
+               if (drive) {
+                       if (drive <= 10)
+                               drive = 0;
+                       else if (drive <= 20)
+                               drive = 1;
+                       else if (drive <= 30)
+                               drive = 2;
+                       else
+                               drive = 3;
+               } else {
+                       drive = fdt_getprop_u32_default_node(fdt, offset, 0,
+                                                            "allwinner,drive",
+                                                             0);
+                       drive = min(drive, 3);
+               }
+
+               if (fdt_get_property(fdt, offset, "bias-disable", NULL))
+                       pull = 0;
+               else if (fdt_get_property(fdt, offset, "bias-pull-up", NULL))
+                       pull = 1;
+               else if (fdt_get_property(fdt, offset, "bias-pull-down", NULL))
+                       pull = 2;
+               else
+                       pull = fdt_getprop_u32_default_node(fdt, offset, 0,
+                                                           "allwinner,pull",
+                                                            0);
+               pull = min(pull, 2);
+
+               for (i = 0; ; i++) {
+                       pin_name = fdt_stringlist_get(fdt, offset,
+                                                     "pins", i, NULL);
+                       if (!pin_name) {
+                               pin_name = fdt_stringlist_get(fdt, offset,
+                                                             "allwinner,pins",
+                                                              i, NULL);
+                               if (!pin_name)
+                                       break;
+                       }
+
+                       pin = name_to_gpio(pin_name);
+                       if (pin < 0)
+                               break;
+
+                       sunxi_gpio_set_cfgpin(pin, SUNXI_GPC_SPI0);
+                       sunxi_gpio_set_drv(pin, drive);
+                       sunxi_gpio_set_pull(pin, pull);
+               }
+       }
+       return 0;
+}
+
+static inline void sun4i_spi_enable_clock(void)
+{
+       struct sunxi_ccm_reg *const ccm =
+               (struct sunxi_ccm_reg *const)SUNXI_CCM_BASE;
+
+       setbits_le32(&ccm->ahb_gate0, (1 << AHB_GATE_OFFSET_SPI0));
+       writel((1 << 31), &ccm->spi0_clk_cfg);
+}
+
+static int sun4i_spi_ofdata_to_platdata(struct udevice *bus)
+{
+       struct sun4i_spi_platdata *plat = dev_get_platdata(bus);
+       int node = dev_of_offset(bus);
+
+       plat->base_addr = devfdt_get_addr(bus);
+       plat->max_hz = fdtdec_get_int(gd->fdt_blob, node,
+                                     "spi-max-frequency",
+                                     SUN4I_SPI_DEFAULT_RATE);
+
+       if (plat->max_hz > SUN4I_SPI_MAX_RATE)
+               plat->max_hz = SUN4I_SPI_MAX_RATE;
+
+       return 0;
+}
+
+static int sun4i_spi_probe(struct udevice *bus)
+{
+       struct sun4i_spi_platdata *plat = dev_get_platdata(bus);
+       struct sun4i_spi_priv *priv = dev_get_priv(bus);
+
+       sun4i_spi_enable_clock();
+       sun4i_spi_parse_pins(bus);
+
+       priv->regs = (struct sun4i_spi_regs *)(uintptr_t)plat->base_addr;
+       priv->freq = plat->max_hz;
+
+       return 0;
+}
+
+static int sun4i_spi_claim_bus(struct udevice *dev)
+{
+       struct sun4i_spi_priv *priv = dev_get_priv(dev->parent);
+
+       writel(SUN4I_CTL_ENABLE | SUN4I_CTL_MASTER | SUN4I_CTL_TP |
+              SUN4I_CTL_CS_MANUAL | SUN4I_CTL_CS_ACTIVE_LOW,
+              &priv->regs->ctl);
+       return 0;
+}
+
+static int sun4i_spi_release_bus(struct udevice *dev)
+{
+       struct sun4i_spi_priv *priv = dev_get_priv(dev->parent);
+       u32 reg;
+
+       reg = readl(&priv->regs->ctl);
+       reg &= ~SUN4I_CTL_ENABLE;
+       writel(reg, &priv->regs->ctl);
+
+       return 0;
+}
+
+static int sun4i_spi_xfer(struct udevice *dev, unsigned int bitlen,
+                         const void *dout, void *din, unsigned long flags)
+{
+       struct udevice *bus = dev->parent;
+       struct sun4i_spi_priv *priv = dev_get_priv(bus);
+       struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
+
+       u32 len = bitlen / 8;
+       u32 reg;
+       u8 nbytes;
+       int ret;
+
+       priv->tx_buf = dout;
+       priv->rx_buf = din;
+
+       if (bitlen % 8) {
+               debug("%s: non byte-aligned SPI transfer.\n", __func__);
+               return -ENAVAIL;
+       }
+
+       if (flags & SPI_XFER_BEGIN)
+               sun4i_spi_set_cs(bus, slave_plat->cs, true);
+
+       reg = readl(&priv->regs->ctl);
+
+       /* Reset FIFOs */
+       writel(reg | SUN4I_CTL_RF_RST | SUN4I_CTL_TF_RST, &priv->regs->ctl);
+
+       while (len) {
+               /* Setup the transfer now... */
+               nbytes = min(len, (u32)(SUN4I_FIFO_DEPTH - 1));
+
+               /* Setup the counters */
+               writel(SUN4I_BURST_CNT(nbytes), &priv->regs->bc);
+               writel(SUN4I_XMIT_CNT(nbytes), &priv->regs->tc);
+
+               /* Fill the TX FIFO */
+               sun4i_spi_fill_fifo(priv, nbytes);
+
+               /* Start the transfer */
+               reg = readl(&priv->regs->ctl);
+               writel(reg | SUN4I_CTL_XCH, &priv->regs->ctl);
+
+               /* Wait transfer to complete */
+               ret = wait_for_bit_le32(&priv->regs->ctl, SUN4I_CTL_XCH_MASK,
+                                       false, SUN4I_SPI_TIMEOUT_US, false);
+               if (ret) {
+                       printf("ERROR: sun4i_spi: Timeout transferring data\n");
+                       sun4i_spi_set_cs(bus, slave_plat->cs, false);
+                       return ret;
+               }
+
+               /* Drain the RX FIFO */
+               sun4i_spi_drain_fifo(priv, nbytes);
+
+               len -= nbytes;
+       }
+
+       if (flags & SPI_XFER_END)
+               sun4i_spi_set_cs(bus, slave_plat->cs, false);
+
+       return 0;
+}
+
+static int sun4i_spi_set_speed(struct udevice *dev, uint speed)
+{
+       struct sun4i_spi_platdata *plat = dev_get_platdata(dev);
+       struct sun4i_spi_priv *priv = dev_get_priv(dev);
+       unsigned int div;
+       u32 reg;
+
+       if (speed > plat->max_hz)
+               speed = plat->max_hz;
+
+       if (speed < SUN4I_SPI_MIN_RATE)
+               speed = SUN4I_SPI_MIN_RATE;
+       /*
+        * Setup clock divider.
+        *
+        * We have two choices there. Either we can use the clock
+        * divide rate 1, which is calculated thanks to this formula:
+        * SPI_CLK = MOD_CLK / (2 ^ (cdr + 1))
+        * Or we can use CDR2, which is calculated with the formula:
+        * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
+        * Whether we use the former or the latter is set through the
+        * DRS bit.
+        *
+        * First try CDR2, and if we can't reach the expected
+        * frequency, fall back to CDR1.
+        */
+
+       div = SUN4I_SPI_MAX_RATE / (2 * speed);
+       reg = readl(&priv->regs->cctl);
+
+       if (div <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) {
+               if (div > 0)
+                       div--;
+
+               reg &= ~(SUN4I_CLK_CTL_CDR2_MASK | SUN4I_CLK_CTL_DRS);
+               reg |= SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS;
+       } else {
+               div = __ilog2(SUN4I_SPI_MAX_RATE) - __ilog2(speed);
+               reg &= ~((SUN4I_CLK_CTL_CDR1_MASK << 8) | SUN4I_CLK_CTL_DRS);
+               reg |= SUN4I_CLK_CTL_CDR1(div);
+       }
+
+       priv->freq = speed;
+       writel(reg, &priv->regs->cctl);
+
+       return 0;
+}
+
+static int sun4i_spi_set_mode(struct udevice *dev, uint mode)
+{
+       struct sun4i_spi_priv *priv = dev_get_priv(dev);
+       u32 reg;
+
+       reg = readl(&priv->regs->ctl);
+       reg &= ~(SUN4I_CTL_CPOL | SUN4I_CTL_CPHA);
+
+       if (mode & SPI_CPOL)
+               reg |= SUN4I_CTL_CPOL;
+
+       if (mode & SPI_CPHA)
+               reg |= SUN4I_CTL_CPHA;
+
+       priv->mode = mode;
+       writel(reg, &priv->regs->ctl);
+
+       return 0;
+}
+
+static const struct dm_spi_ops sun4i_spi_ops = {
+       .claim_bus              = sun4i_spi_claim_bus,
+       .release_bus            = sun4i_spi_release_bus,
+       .xfer                   = sun4i_spi_xfer,
+       .set_speed              = sun4i_spi_set_speed,
+       .set_mode               = sun4i_spi_set_mode,
+};
+
+static const struct udevice_id sun4i_spi_ids[] = {
+       { .compatible = "allwinner,sun4i-a10-spi"  },
+       { }
+};
+
+U_BOOT_DRIVER(sun4i_spi) = {
+       .name   = "sun4i_spi",
+       .id     = UCLASS_SPI,
+       .of_match       = sun4i_spi_ids,
+       .ops    = &sun4i_spi_ops,
+       .ofdata_to_platdata     = sun4i_spi_ofdata_to_platdata,
+       .platdata_auto_alloc_size       = sizeof(struct sun4i_spi_platdata),
+       .priv_auto_alloc_size   = sizeof(struct sun4i_spi_priv),
+       .probe  = sun4i_spi_probe,
+};