spi: Add Amlogic Meson SPI Flash Controller driver
authorNeil Armstrong <narmstrong@baylibre.com>
Thu, 22 Nov 2018 10:01:05 +0000 (11:01 +0100)
committerJagan Teki <jagan@amarulasolutions.com>
Sat, 24 Nov 2018 09:11:12 +0000 (14:41 +0530)
The Amlogic Meson SoCs embeds a Flash oriented SPI Controller name SPIFC.
This driver, ported from the Linux meson-spi-spifc driver, add support
for this controller on the Amlogic Meson GX SoCs in U-Boot.

Tested-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
drivers/spi/Kconfig
drivers/spi/Makefile
drivers/spi/meson_spifc.c [new file with mode: 0644]

index 516188e..6085788 100644 (file)
@@ -116,6 +116,14 @@ config ICH_SPI
          access the SPI NOR flash on platforms embedding this Intel
          ICH IP core.
 
+config MESON_SPIFC
+       bool "Amlogic Meson SPI Flash Controller driver"
+       depends on ARCH_MESON
+       help
+         Enable the Amlogic Meson SPI Flash Controller SPIFC) driver.
+         This driver can be used to access the SPI NOR flash chips on
+         Amlogic Meson SoCs.
+
 config MT7621_SPI
        bool "MediaTek MT7621 SPI driver"
        depends on ARCH_MT7620
index 7242ea7..67b42da 100644 (file)
@@ -31,6 +31,7 @@ obj-$(CONFIG_FSL_QSPI) += fsl_qspi.o
 obj-$(CONFIG_ICH_SPI) +=  ich.o
 obj-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
 obj-$(CONFIG_LPC32XX_SSP) += lpc32xx_ssp.o
+obj-$(CONFIG_MESON_SPIFC) += meson_spifc.o
 obj-$(CONFIG_MPC8XX_SPI) += mpc8xx_spi.o
 obj-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 obj-$(CONFIG_MT7621_SPI) += mt7621_spi.o
diff --git a/drivers/spi/meson_spifc.c b/drivers/spi/meson_spifc.c
new file mode 100644 (file)
index 0000000..3d55169
--- /dev/null
@@ -0,0 +1,320 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
+ * Copyright (C) 2018 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ * Amlogic Meson SPI Flash Controller driver
+ */
+
+#include <common.h>
+#include <spi.h>
+#include <clk.h>
+#include <dm.h>
+#include <regmap.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <linux/bitfield.h>
+
+/* register map */
+#define REG_CMD                        0x00
+#define REG_ADDR               0x04
+#define REG_CTRL               0x08
+#define REG_CTRL1              0x0c
+#define REG_STATUS             0x10
+#define REG_CTRL2              0x14
+#define REG_CLOCK              0x18
+#define REG_USER               0x1c
+#define REG_USER1              0x20
+#define REG_USER2              0x24
+#define REG_USER3              0x28
+#define REG_USER4              0x2c
+#define REG_SLAVE              0x30
+#define REG_SLAVE1             0x34
+#define REG_SLAVE2             0x38
+#define REG_SLAVE3             0x3c
+#define REG_C0                 0x40
+#define REG_B8                 0x60
+#define REG_MAX                        0x7c
+
+/* register fields */
+#define CMD_USER               BIT(18)
+#define CTRL_ENABLE_AHB                BIT(17)
+#define CLOCK_SOURCE           BIT(31)
+#define CLOCK_DIV_SHIFT                12
+#define CLOCK_DIV_MASK         (0x3f << CLOCK_DIV_SHIFT)
+#define CLOCK_CNT_HIGH_SHIFT   6
+#define CLOCK_CNT_HIGH_MASK    (0x3f << CLOCK_CNT_HIGH_SHIFT)
+#define CLOCK_CNT_LOW_SHIFT    0
+#define CLOCK_CNT_LOW_MASK     (0x3f << CLOCK_CNT_LOW_SHIFT)
+#define USER_DIN_EN_MS         BIT(0)
+#define USER_CMP_MODE          BIT(2)
+#define USER_CLK_NOT_INV       BIT(7)
+#define USER_UC_DOUT_SEL       BIT(27)
+#define USER_UC_DIN_SEL                BIT(28)
+#define USER_UC_MASK           ((BIT(5) - 1) << 27)
+#define USER1_BN_UC_DOUT_SHIFT 17
+#define USER1_BN_UC_DOUT_MASK  (0xff << 16)
+#define USER1_BN_UC_DIN_SHIFT  8
+#define USER1_BN_UC_DIN_MASK   (0xff << 8)
+#define USER4_CS_POL_HIGH      BIT(23)
+#define USER4_IDLE_CLK_HIGH    BIT(29)
+#define USER4_CS_ACT           BIT(30)
+#define SLAVE_TRST_DONE                BIT(4)
+#define SLAVE_OP_MODE          BIT(30)
+#define SLAVE_SW_RST           BIT(31)
+
+#define SPIFC_BUFFER_SIZE      64
+
+struct meson_spifc_priv {
+       struct regmap                   *regmap;
+       struct clk                      clk;
+};
+
+/**
+ * meson_spifc_drain_buffer() - copy data from device buffer to memory
+ * @spifc:     the Meson SPI device
+ * @buf:       the destination buffer
+ * @len:       number of bytes to copy
+ */
+static void meson_spifc_drain_buffer(struct meson_spifc_priv *spifc,
+                                    u8 *buf, int len)
+{
+       u32 data;
+       int i = 0;
+
+       while (i < len) {
+               regmap_read(spifc->regmap, REG_C0 + i, &data);
+
+               if (len - i >= 4) {
+                       *((u32 *)buf) = data;
+                       buf += 4;
+               } else {
+                       memcpy(buf, &data, len - i);
+                       break;
+               }
+               i += 4;
+       }
+}
+
+/**
+ * meson_spifc_fill_buffer() - copy data from memory to device buffer
+ * @spifc:     the Meson SPI device
+ * @buf:       the source buffer
+ * @len:       number of bytes to copy
+ */
+static void meson_spifc_fill_buffer(struct meson_spifc_priv *spifc,
+                                   const u8 *buf, int len)
+{
+       u32 data = 0;
+       int i = 0;
+
+       while (i < len) {
+               if (len - i >= 4)
+                       data = *(u32 *)buf;
+               else
+                       memcpy(&data, buf, len - i);
+
+               regmap_write(spifc->regmap, REG_C0 + i, data);
+
+               buf += 4;
+               i += 4;
+       }
+}
+
+/**
+ * meson_spifc_txrx() - transfer a chunk of data
+ * @spifc:     the Meson SPI device
+ * @dout:      data buffer for TX
+ * @din:       data buffer for RX
+ * @offset:    offset of the data to transfer
+ * @len:       length of the data to transfer
+ * @last_xfer: whether this is the last transfer of the message
+ * @last_chunk:        whether this is the last chunk of the transfer
+ * Return:     0 on success, a negative value on error
+ */
+static int meson_spifc_txrx(struct meson_spifc_priv *spifc,
+                           const u8 *dout, u8 *din, int offset,
+                           int len, bool last_xfer, bool last_chunk)
+{
+       bool keep_cs = true;
+       u32 data;
+       int ret;
+
+       if (dout)
+               meson_spifc_fill_buffer(spifc, dout + offset, len);
+
+       /* enable DOUT stage */
+       regmap_update_bits(spifc->regmap, REG_USER, USER_UC_MASK,
+                          USER_UC_DOUT_SEL);
+       regmap_write(spifc->regmap, REG_USER1,
+                    (8 * len - 1) << USER1_BN_UC_DOUT_SHIFT);
+
+       /* enable data input during DOUT */
+       regmap_update_bits(spifc->regmap, REG_USER, USER_DIN_EN_MS,
+                          USER_DIN_EN_MS);
+
+       if (last_chunk && last_xfer)
+               keep_cs = false;
+
+       regmap_update_bits(spifc->regmap, REG_USER4, USER4_CS_ACT,
+                          keep_cs ? USER4_CS_ACT : 0);
+
+       /* clear transition done bit */
+       regmap_update_bits(spifc->regmap, REG_SLAVE, SLAVE_TRST_DONE, 0);
+       /* start transfer */
+       regmap_update_bits(spifc->regmap, REG_CMD, CMD_USER, CMD_USER);
+
+       /* wait for the current operation to terminate */
+       ret = regmap_read_poll_timeout(spifc->regmap, REG_SLAVE, data,
+                                      (data & SLAVE_TRST_DONE),
+                                      0, 5 * CONFIG_SYS_HZ);
+
+       if (!ret && din)
+               meson_spifc_drain_buffer(spifc, din + offset, len);
+
+       return ret;
+}
+
+/**
+ * meson_spifc_xfer() - perform a single transfer
+ * @dev:       the SPI controller device
+ * @bitlen:    length of the transfer
+ * @dout:      data buffer for TX
+ * @din:       data buffer for RX
+ * @flags:     transfer flags
+ * Return:     0 on success, a negative value on error
+ */
+static int meson_spifc_xfer(struct udevice *slave, unsigned int bitlen,
+                           const void *dout, void *din, unsigned long flags)
+{
+       struct meson_spifc_priv *spifc = dev_get_priv(slave->parent);
+       int blen = bitlen / 8;
+       int len, done = 0, ret = 0;
+
+       if (bitlen % 8)
+               return -EINVAL;
+
+       debug("xfer len %d (%d) dout %p din %p\n", bitlen, blen, dout, din);
+
+       regmap_update_bits(spifc->regmap, REG_CTRL, CTRL_ENABLE_AHB, 0);
+
+       while (done < blen && !ret) {
+               len = min_t(int, blen - done, SPIFC_BUFFER_SIZE);
+               ret = meson_spifc_txrx(spifc, dout, din, done, len,
+                                      flags & SPI_XFER_END,
+                                      done + len >= blen);
+               done += len;
+       }
+
+       regmap_update_bits(spifc->regmap, REG_CTRL, CTRL_ENABLE_AHB,
+                          CTRL_ENABLE_AHB);
+
+       return ret;
+}
+
+/**
+ * meson_spifc_set_speed() - program the clock divider
+ * @dev:       the SPI controller device
+ * @speed:     desired speed in Hz
+ */
+static int meson_spifc_set_speed(struct udevice *dev, uint speed)
+{
+       struct meson_spifc_priv *spifc = dev_get_priv(dev);
+       unsigned long parent, value;
+       int n;
+
+       parent = clk_get_rate(&spifc->clk);
+       n = max_t(int, parent / speed - 1, 1);
+
+       debug("parent %lu, speed %u, n %d\n", parent, speed, n);
+
+       value = (n << CLOCK_DIV_SHIFT) & CLOCK_DIV_MASK;
+       value |= (n << CLOCK_CNT_LOW_SHIFT) & CLOCK_CNT_LOW_MASK;
+       value |= (((n + 1) / 2 - 1) << CLOCK_CNT_HIGH_SHIFT) &
+               CLOCK_CNT_HIGH_MASK;
+
+       regmap_write(spifc->regmap, REG_CLOCK, value);
+
+       return 0;
+}
+
+/**
+ * meson_spifc_set_mode() - setups the SPI bus mode
+ * @dev:       the SPI controller device
+ * @mode:      desired mode bitfield
+ * Return:     0 on success, -ENODEV on error
+ */
+static int meson_spifc_set_mode(struct udevice *dev, uint mode)
+{
+       struct meson_spifc_priv *spifc = dev_get_priv(dev);
+
+       if (mode & (SPI_CPHA | SPI_RX_QUAD | SPI_RX_DUAL |
+                   SPI_TX_QUAD | SPI_TX_DUAL))
+               return -ENODEV;
+
+       regmap_update_bits(spifc->regmap, REG_USER, USER_CLK_NOT_INV,
+                          mode & SPI_CPOL ? USER_CLK_NOT_INV : 0);
+
+       regmap_update_bits(spifc->regmap, REG_USER4, USER4_CS_POL_HIGH,
+                          mode & SPI_CS_HIGH ? USER4_CS_POL_HIGH : 0);
+
+       return 0;
+}
+
+/**
+ * meson_spifc_hw_init() - reset and initialize the SPI controller
+ * @spifc:     the Meson SPI device
+ */
+static void meson_spifc_hw_init(struct meson_spifc_priv *spifc)
+{
+       /* reset device */
+       regmap_update_bits(spifc->regmap, REG_SLAVE, SLAVE_SW_RST,
+                          SLAVE_SW_RST);
+       /* disable compatible mode */
+       regmap_update_bits(spifc->regmap, REG_USER, USER_CMP_MODE, 0);
+       /* set master mode */
+       regmap_update_bits(spifc->regmap, REG_SLAVE, SLAVE_OP_MODE, 0);
+}
+
+static const struct dm_spi_ops meson_spifc_ops = {
+       .xfer           = meson_spifc_xfer,
+       .set_speed      = meson_spifc_set_speed,
+       .set_mode       = meson_spifc_set_mode,
+};
+
+static int meson_spifc_probe(struct udevice *dev)
+{
+       struct meson_spifc_priv *priv = dev_get_priv(dev);
+       int ret;
+
+       ret = regmap_init_mem(dev_ofnode(dev), &priv->regmap);
+       if (ret)
+               return ret;
+
+       ret = clk_get_by_index(dev, 0, &priv->clk);
+       if (ret)
+               return ret;
+
+       ret = clk_enable(&priv->clk);
+       if (ret)
+               return ret;
+
+       meson_spifc_hw_init(priv);
+
+       return 0;
+}
+
+static const struct udevice_id meson_spifc_ids[] = {
+       { .compatible = "amlogic,meson-gxbb-spifc", },
+       { }
+};
+
+U_BOOT_DRIVER(meson_spifc) = {
+       .name           = "meson_spifc",
+       .id             = UCLASS_SPI,
+       .of_match       = meson_spifc_ids,
+       .ops            = &meson_spifc_ops,
+       .probe          = meson_spifc_probe,
+       .priv_auto_alloc_size = sizeof(struct meson_spifc_priv),
+};