summaryrefslogtreecommitdiff
path: root/drivers/spi
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/Kconfig11
-rw-r--r--drivers/spi/Makefile1
-rw-r--r--drivers/spi/spi-aspeed-smc.c1210
3 files changed, 1222 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index f56fa715d4e7..38117775ff79 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -101,6 +101,17 @@ config SPI_ARMADA_3700
This enables support for the SPI controller present on the
Marvell Armada 3700 SoCs.
+config SPI_ASPEED_SMC
+ tristate "Aspeed flash controllers in SPI mode"
+ depends on ARCH_ASPEED || COMPILE_TEST
+ depends on OF
+ help
+ This enables support for the Firmware Memory controller (FMC)
+ in the Aspeed AST2600, AST2500 and AST2400 SoCs when attached
+ to SPI NOR chips, and support for the SPI flash memory
+ controller (SPI) for the host firmware. The implementation
+ only supports SPI NOR.
+
config SPI_ATMEL
tristate "Atmel SPI Controller"
depends on ARCH_AT91 || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 51541ff17e67..0f44eb6083a5 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_SPI_ALTERA_CORE) += spi-altera-core.o
obj-$(CONFIG_SPI_ALTERA_DFL) += spi-altera-dfl.o
obj-$(CONFIG_SPI_AR934X) += spi-ar934x.o
obj-$(CONFIG_SPI_ARMADA_3700) += spi-armada-3700.o
+obj-$(CONFIG_SPI_ASPEED_SMC) += spi-aspeed-smc.o
obj-$(CONFIG_SPI_ATMEL) += spi-atmel.o
obj-$(CONFIG_SPI_ATMEL_QUADSPI) += atmel-quadspi.o
obj-$(CONFIG_SPI_AT91_USART) += spi-at91-usart.o
diff --git a/drivers/spi/spi-aspeed-smc.c b/drivers/spi/spi-aspeed-smc.c
new file mode 100644
index 000000000000..496f3e1e9079
--- /dev/null
+++ b/drivers/spi/spi-aspeed-smc.c
@@ -0,0 +1,1210 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * ASPEED FMC/SPI Memory Controller Driver
+ *
+ * Copyright (c) 2015-2022, IBM Corporation.
+ * Copyright (c) 2020, ASPEED Corporation.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+
+#define DEVICE_NAME "spi-aspeed-smc"
+
+/* Type setting Register */
+#define CONFIG_REG 0x0
+#define CONFIG_TYPE_SPI 0x2
+
+/* CE Control Register */
+#define CE_CTRL_REG 0x4
+
+/* CEx Control Register */
+#define CE0_CTRL_REG 0x10
+#define CTRL_IO_MODE_MASK GENMASK(30, 28)
+#define CTRL_IO_SINGLE_DATA 0x0
+#define CTRL_IO_DUAL_DATA BIT(29)
+#define CTRL_IO_QUAD_DATA BIT(30)
+#define CTRL_COMMAND_SHIFT 16
+#define CTRL_IO_ADDRESS_4B BIT(13) /* AST2400 SPI only */
+#define CTRL_IO_DUMMY_SET(dummy) \
+ (((((dummy) >> 2) & 0x1) << 14) | (((dummy) & 0x3) << 6))
+#define CTRL_FREQ_SEL_SHIFT 8
+#define CTRL_FREQ_SEL_MASK GENMASK(11, CTRL_FREQ_SEL_SHIFT)
+#define CTRL_CE_STOP_ACTIVE BIT(2)
+#define CTRL_IO_MODE_CMD_MASK GENMASK(1, 0)
+#define CTRL_IO_MODE_NORMAL 0x0
+#define CTRL_IO_MODE_READ 0x1
+#define CTRL_IO_MODE_WRITE 0x2
+#define CTRL_IO_MODE_USER 0x3
+
+#define CTRL_IO_CMD_MASK 0xf0ff40c3
+
+/* CEx Address Decoding Range Register */
+#define CE0_SEGMENT_ADDR_REG 0x30
+
+/* CEx Read timing compensation register */
+#define CE0_TIMING_COMPENSATION_REG 0x94
+
+enum aspeed_spi_ctl_reg_value {
+ ASPEED_SPI_BASE,
+ ASPEED_SPI_READ,
+ ASPEED_SPI_WRITE,
+ ASPEED_SPI_MAX,
+};
+
+struct aspeed_spi;
+
+struct aspeed_spi_chip {
+ struct aspeed_spi *aspi;
+ u32 cs;
+ void __iomem *ctl;
+ void __iomem *ahb_base;
+ u32 ahb_window_size;
+ u32 ctl_val[ASPEED_SPI_MAX];
+ u32 clk_freq;
+};
+
+struct aspeed_spi_data {
+ u32 ctl0;
+ u32 max_cs;
+ bool hastype;
+ u32 mode_bits;
+ u32 we0;
+ u32 timing;
+ u32 hclk_mask;
+ u32 hdiv_max;
+
+ u32 (*segment_start)(struct aspeed_spi *aspi, u32 reg);
+ u32 (*segment_end)(struct aspeed_spi *aspi, u32 reg);
+ u32 (*segment_reg)(struct aspeed_spi *aspi, u32 start, u32 end);
+ int (*calibrate)(struct aspeed_spi_chip *chip, u32 hdiv,
+ const u8 *golden_buf, u8 *test_buf);
+};
+
+#define ASPEED_SPI_MAX_NUM_CS 5
+
+struct aspeed_spi {
+ const struct aspeed_spi_data *data;
+
+ void __iomem *regs;
+ void __iomem *ahb_base;
+ u32 ahb_base_phy;
+ u32 ahb_window_size;
+ struct device *dev;
+
+ struct clk *clk;
+ u32 clk_freq;
+
+ struct aspeed_spi_chip chips[ASPEED_SPI_MAX_NUM_CS];
+};
+
+static u32 aspeed_spi_get_io_mode(const struct spi_mem_op *op)
+{
+ switch (op->data.buswidth) {
+ case 1:
+ return CTRL_IO_SINGLE_DATA;
+ case 2:
+ return CTRL_IO_DUAL_DATA;
+ case 4:
+ return CTRL_IO_QUAD_DATA;
+ default:
+ return CTRL_IO_SINGLE_DATA;
+ }
+}
+
+static void aspeed_spi_set_io_mode(struct aspeed_spi_chip *chip, u32 io_mode)
+{
+ u32 ctl;
+
+ if (io_mode > 0) {
+ ctl = readl(chip->ctl) & ~CTRL_IO_MODE_MASK;
+ ctl |= io_mode;
+ writel(ctl, chip->ctl);
+ }
+}
+
+static void aspeed_spi_start_user(struct aspeed_spi_chip *chip)
+{
+ u32 ctl = chip->ctl_val[ASPEED_SPI_BASE];
+
+ ctl |= CTRL_IO_MODE_USER | CTRL_CE_STOP_ACTIVE;
+ writel(ctl, chip->ctl);
+
+ ctl &= ~CTRL_CE_STOP_ACTIVE;
+ writel(ctl, chip->ctl);
+}
+
+static void aspeed_spi_stop_user(struct aspeed_spi_chip *chip)
+{
+ u32 ctl = chip->ctl_val[ASPEED_SPI_READ] |
+ CTRL_IO_MODE_USER | CTRL_CE_STOP_ACTIVE;
+
+ writel(ctl, chip->ctl);
+
+ /* Restore defaults */
+ writel(chip->ctl_val[ASPEED_SPI_READ], chip->ctl);
+}
+
+static int aspeed_spi_read_from_ahb(void *buf, void __iomem *src, size_t len)
+{
+ size_t offset = 0;
+
+ if (IS_ALIGNED((uintptr_t)src, sizeof(uintptr_t)) &&
+ IS_ALIGNED((uintptr_t)buf, sizeof(uintptr_t))) {
+ ioread32_rep(src, buf, len >> 2);
+ offset = len & ~0x3;
+ len -= offset;
+ }
+ ioread8_rep(src, (u8 *)buf + offset, len);
+ return 0;
+}
+
+static int aspeed_spi_write_to_ahb(void __iomem *dst, const void *buf, size_t len)
+{
+ size_t offset = 0;
+
+ if (IS_ALIGNED((uintptr_t)dst, sizeof(uintptr_t)) &&
+ IS_ALIGNED((uintptr_t)buf, sizeof(uintptr_t))) {
+ iowrite32_rep(dst, buf, len >> 2);
+ offset = len & ~0x3;
+ len -= offset;
+ }
+ iowrite8_rep(dst, (const u8 *)buf + offset, len);
+ return 0;
+}
+
+static int aspeed_spi_send_cmd_addr(struct aspeed_spi_chip *chip, u8 addr_nbytes,
+ u64 offset, u32 opcode)
+{
+ __be32 temp;
+ u32 cmdaddr;
+
+ switch (addr_nbytes) {
+ case 3:
+ cmdaddr = offset & 0xFFFFFF;
+ cmdaddr |= opcode << 24;
+
+ temp = cpu_to_be32(cmdaddr);
+ aspeed_spi_write_to_ahb(chip->ahb_base, &temp, 4);
+ break;
+ case 4:
+ temp = cpu_to_be32(offset);
+ aspeed_spi_write_to_ahb(chip->ahb_base, &opcode, 1);
+ aspeed_spi_write_to_ahb(chip->ahb_base, &temp, 4);
+ break;
+ default:
+ WARN_ONCE(1, "Unexpected address width %u", addr_nbytes);
+ return -EOPNOTSUPP;
+ }
+ return 0;
+}
+
+static int aspeed_spi_read_reg(struct aspeed_spi_chip *chip,
+ const struct spi_mem_op *op)
+{
+ aspeed_spi_start_user(chip);
+ aspeed_spi_write_to_ahb(chip->ahb_base, &op->cmd.opcode, 1);
+ aspeed_spi_read_from_ahb(op->data.buf.in,
+ chip->ahb_base, op->data.nbytes);
+ aspeed_spi_stop_user(chip);
+ return 0;
+}
+
+static int aspeed_spi_write_reg(struct aspeed_spi_chip *chip,
+ const struct spi_mem_op *op)
+{
+ aspeed_spi_start_user(chip);
+ aspeed_spi_write_to_ahb(chip->ahb_base, &op->cmd.opcode, 1);
+ aspeed_spi_write_to_ahb(chip->ahb_base, op->data.buf.out,
+ op->data.nbytes);
+ aspeed_spi_stop_user(chip);
+ return 0;
+}
+
+static ssize_t aspeed_spi_read_user(struct aspeed_spi_chip *chip,
+ const struct spi_mem_op *op,
+ u64 offset, size_t len, void *buf)
+{
+ int io_mode = aspeed_spi_get_io_mode(op);
+ u8 dummy = 0xFF;
+ int i;
+ int ret;
+
+ aspeed_spi_start_user(chip);
+
+ ret = aspeed_spi_send_cmd_addr(chip, op->addr.nbytes, offset, op->cmd.opcode);
+ if (ret < 0)
+ return ret;
+
+ if (op->dummy.buswidth && op->dummy.nbytes) {
+ for (i = 0; i < op->dummy.nbytes / op->dummy.buswidth; i++)
+ aspeed_spi_write_to_ahb(chip->ahb_base, &dummy, sizeof(dummy));
+ }
+
+ aspeed_spi_set_io_mode(chip, io_mode);
+
+ aspeed_spi_read_from_ahb(buf, chip->ahb_base, len);
+ aspeed_spi_stop_user(chip);
+ return 0;
+}
+
+static ssize_t aspeed_spi_write_user(struct aspeed_spi_chip *chip,
+ const struct spi_mem_op *op)
+{
+ int ret;
+
+ aspeed_spi_start_user(chip);
+ ret = aspeed_spi_send_cmd_addr(chip, op->addr.nbytes, op->addr.val, op->cmd.opcode);
+ if (ret < 0)
+ return ret;
+ aspeed_spi_write_to_ahb(chip->ahb_base, op->data.buf.out, op->data.nbytes);
+ aspeed_spi_stop_user(chip);
+ return 0;
+}
+
+/* support for 1-1-1, 1-1-2 or 1-1-4 */
+static bool aspeed_spi_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+ if (op->cmd.buswidth > 1)
+ return false;
+
+ if (op->addr.nbytes != 0) {
+ if (op->addr.buswidth > 1)
+ return false;
+ if (op->addr.nbytes < 3 || op->addr.nbytes > 4)
+ return false;
+ }
+
+ if (op->dummy.nbytes != 0) {
+ if (op->dummy.buswidth > 1 || op->dummy.nbytes > 7)
+ return false;
+ }
+
+ if (op->data.nbytes != 0 && op->data.buswidth > 4)
+ return false;
+
+ return spi_mem_default_supports_op(mem, op);
+}
+
+static const struct aspeed_spi_data ast2400_spi_data;
+
+static int do_aspeed_spi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+ struct aspeed_spi *aspi = spi_controller_get_devdata(mem->spi->master);
+ struct aspeed_spi_chip *chip = &aspi->chips[mem->spi->chip_select];
+ u32 addr_mode, addr_mode_backup;
+ u32 ctl_val;
+ int ret = 0;
+
+ dev_dbg(aspi->dev,
+ "CE%d %s OP %#x mode:%d.%d.%d.%d naddr:%#x ndummies:%#x len:%#x",
+ chip->cs, op->data.dir == SPI_MEM_DATA_IN ? "read" : "write",
+ op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
+ op->dummy.buswidth, op->data.buswidth,
+ op->addr.nbytes, op->dummy.nbytes, op->data.nbytes);
+
+ addr_mode = readl(aspi->regs + CE_CTRL_REG);
+ addr_mode_backup = addr_mode;
+
+ ctl_val = chip->ctl_val[ASPEED_SPI_BASE];
+ ctl_val &= ~CTRL_IO_CMD_MASK;
+
+ ctl_val |= op->cmd.opcode << CTRL_COMMAND_SHIFT;
+
+ /* 4BYTE address mode */
+ if (op->addr.nbytes) {
+ if (op->addr.nbytes == 4)
+ addr_mode |= (0x11 << chip->cs);
+ else
+ addr_mode &= ~(0x11 << chip->cs);
+
+ if (op->addr.nbytes == 4 && chip->aspi->data == &ast2400_spi_data)
+ ctl_val |= CTRL_IO_ADDRESS_4B;
+ }
+
+ if (op->dummy.nbytes)
+ ctl_val |= CTRL_IO_DUMMY_SET(op->dummy.nbytes / op->dummy.buswidth);
+
+ if (op->data.nbytes)
+ ctl_val |= aspeed_spi_get_io_mode(op);
+
+ if (op->data.dir == SPI_MEM_DATA_OUT)
+ ctl_val |= CTRL_IO_MODE_WRITE;
+ else
+ ctl_val |= CTRL_IO_MODE_READ;
+
+ if (addr_mode != addr_mode_backup)
+ writel(addr_mode, aspi->regs + CE_CTRL_REG);
+ writel(ctl_val, chip->ctl);
+
+ if (op->data.dir == SPI_MEM_DATA_IN) {
+ if (!op->addr.nbytes)
+ ret = aspeed_spi_read_reg(chip, op);
+ else
+ ret = aspeed_spi_read_user(chip, op, op->addr.val,
+ op->data.nbytes, op->data.buf.in);
+ } else {
+ if (!op->addr.nbytes)
+ ret = aspeed_spi_write_reg(chip, op);
+ else
+ ret = aspeed_spi_write_user(chip, op);
+ }
+
+ /* Restore defaults */
+ if (addr_mode != addr_mode_backup)
+ writel(addr_mode_backup, aspi->regs + CE_CTRL_REG);
+ writel(chip->ctl_val[ASPEED_SPI_READ], chip->ctl);
+ return ret;
+}
+
+static int aspeed_spi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+ int ret;
+
+ ret = do_aspeed_spi_exec_op(mem, op);
+ if (ret)
+ dev_err(&mem->spi->dev, "operation failed: %d\n", ret);
+ return ret;
+}
+
+static const char *aspeed_spi_get_name(struct spi_mem *mem)
+{
+ struct aspeed_spi *aspi = spi_controller_get_devdata(mem->spi->master);
+ struct device *dev = aspi->dev;
+
+ return devm_kasprintf(dev, GFP_KERNEL, "%s.%d", dev_name(dev), mem->spi->chip_select);
+}
+
+struct aspeed_spi_window {
+ u32 cs;
+ u32 offset;
+ u32 size;
+};
+
+static void aspeed_spi_get_windows(struct aspeed_spi *aspi,
+ struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS])
+{
+ const struct aspeed_spi_data *data = aspi->data;
+ u32 reg_val;
+ u32 cs;
+
+ for (cs = 0; cs < aspi->data->max_cs; cs++) {
+ reg_val = readl(aspi->regs + CE0_SEGMENT_ADDR_REG + cs * 4);
+ windows[cs].cs = cs;
+ windows[cs].size = data->segment_end(aspi, reg_val) -
+ data->segment_start(aspi, reg_val);
+ windows[cs].offset = cs ? windows[cs - 1].offset + windows[cs - 1].size : 0;
+ dev_vdbg(aspi->dev, "CE%d offset=0x%.8x size=0x%x\n", cs,
+ windows[cs].offset, windows[cs].size);
+ }
+}
+
+/*
+ * On the AST2600, some CE windows are closed by default at reset but
+ * U-Boot should open all.
+ */
+static int aspeed_spi_chip_set_default_window(struct aspeed_spi_chip *chip)
+{
+ struct aspeed_spi *aspi = chip->aspi;
+ struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS] = { 0 };
+ struct aspeed_spi_window *win = &windows[chip->cs];
+
+ /* No segment registers for the AST2400 SPI controller */
+ if (aspi->data == &ast2400_spi_data) {
+ win->offset = 0;
+ win->size = aspi->ahb_window_size;
+ } else {
+ aspeed_spi_get_windows(aspi, windows);
+ }
+
+ chip->ahb_base = aspi->ahb_base + win->offset;
+ chip->ahb_window_size = win->size;
+
+ dev_dbg(aspi->dev, "CE%d default window [ 0x%.8x - 0x%.8x ] %dMB",
+ chip->cs, aspi->ahb_base_phy + win->offset,
+ aspi->ahb_base_phy + win->offset + win->size - 1,
+ win->size >> 20);
+
+ return chip->ahb_window_size ? 0 : -1;
+}
+
+static int aspeed_spi_set_window(struct aspeed_spi *aspi,
+ const struct aspeed_spi_window *win)
+{
+ u32 start = aspi->ahb_base_phy + win->offset;
+ u32 end = start + win->size;
+ void __iomem *seg_reg = aspi->regs + CE0_SEGMENT_ADDR_REG + win->cs * 4;
+ u32 seg_val_backup = readl(seg_reg);
+ u32 seg_val = aspi->data->segment_reg(aspi, start, end);
+
+ if (seg_val == seg_val_backup)
+ return 0;
+
+ writel(seg_val, seg_reg);
+
+ /*
+ * Restore initial value if something goes wrong else we could
+ * loose access to the chip.
+ */
+ if (seg_val != readl(seg_reg)) {
+ dev_err(aspi->dev, "CE%d invalid window [ 0x%.8x - 0x%.8x ] %dMB",
+ win->cs, start, end - 1, win->size >> 20);
+ writel(seg_val_backup, seg_reg);
+ return -EIO;
+ }
+
+ if (win->size)
+ dev_dbg(aspi->dev, "CE%d new window [ 0x%.8x - 0x%.8x ] %dMB",
+ win->cs, start, end - 1, win->size >> 20);
+ else
+ dev_dbg(aspi->dev, "CE%d window closed", win->cs);
+
+ return 0;
+}
+
+/*
+ * Yet to be done when possible :
+ * - Align mappings on flash size (we don't have the info)
+ * - ioremap each window, not strictly necessary since the overall window
+ * is correct.
+ */
+static const struct aspeed_spi_data ast2500_spi_data;
+static const struct aspeed_spi_data ast2600_spi_data;
+static const struct aspeed_spi_data ast2600_fmc_data;
+
+static int aspeed_spi_chip_adjust_window(struct aspeed_spi_chip *chip,
+ u32 local_offset, u32 size)
+{
+ struct aspeed_spi *aspi = chip->aspi;
+ struct aspeed_spi_window windows[ASPEED_SPI_MAX_NUM_CS] = { 0 };
+ struct aspeed_spi_window *win = &windows[chip->cs];
+ int ret;
+
+ /* No segment registers for the AST2400 SPI controller */
+ if (aspi->data == &ast2400_spi_data)
+ return 0;
+
+ /*
+ * Due to an HW issue on the AST2500 SPI controller, the CE0
+ * window size should be smaller than the maximum 128MB.
+ */
+ if (aspi->data == &ast2500_spi_data && chip->cs == 0 && size == SZ_128M) {
+ size = 120 << 20;
+ dev_info(aspi->dev, "CE%d window resized to %dMB (AST2500 HW quirk)",
+ chip->cs, size >> 20);
+ }
+
+ /*
+ * The decoding size of AST2600 SPI controller should set at
+ * least 2MB.
+ */
+ if ((aspi->data == &ast2600_spi_data || aspi->data == &ast2600_fmc_data) &&
+ size < SZ_2M) {
+ size = SZ_2M;
+ dev_info(aspi->dev, "CE%d window resized to %dMB (AST2600 Decoding)",
+ chip->cs, size >> 20);
+ }
+
+ aspeed_spi_get_windows(aspi, windows);
+
+ /* Adjust this chip window */
+ win->offset += local_offset;
+ win->size = size;
+
+ if (win->offset + win->size > aspi->ahb_window_size) {
+ win->size = aspi->ahb_window_size - win->offset;
+ dev_warn(aspi->dev, "CE%d window resized to %dMB", chip->cs, win->size >> 20);
+ }
+
+ ret = aspeed_spi_set_window(aspi, win);
+ if (ret)
+ return ret;
+
+ /* Update chip mapping info */
+ chip->ahb_base = aspi->ahb_base + win->offset;
+ chip->ahb_window_size = win->size;
+
+ /*
+ * Also adjust next chip window to make sure that it does not
+ * overlap with the current window.
+ */
+ if (chip->cs < aspi->data->max_cs - 1) {
+ struct aspeed_spi_window *next = &windows[chip->cs + 1];
+
+ /* Change offset and size to keep the same end address */
+ if ((next->offset + next->size) > (win->offset + win->size))
+ next->size = (next->offset + next->size) - (win->offset + win->size);
+ else
+ next->size = 0;
+ next->offset = win->offset + win->size;
+
+ aspeed_spi_set_window(aspi, next);
+ }
+ return 0;
+}
+
+static int aspeed_spi_do_calibration(struct aspeed_spi_chip *chip);
+
+static int aspeed_spi_dirmap_create(struct spi_mem_dirmap_desc *desc)
+{
+ struct aspeed_spi *aspi = spi_controller_get_devdata(desc->mem->spi->master);
+ struct aspeed_spi_chip *chip = &aspi->chips[desc->mem->spi->chip_select];
+ struct spi_mem_op *op = &desc->info.op_tmpl;
+ u32 ctl_val;
+ int ret = 0;
+
+ chip->clk_freq = desc->mem->spi->max_speed_hz;
+
+ /* Only for reads */
+ if (op->data.dir != SPI_MEM_DATA_IN)
+ return -EOPNOTSUPP;
+
+ aspeed_spi_chip_adjust_window(chip, desc->info.offset, desc->info.length);
+
+ if (desc->info.length > chip->ahb_window_size)
+ dev_warn(aspi->dev, "CE%d window (%dMB) too small for mapping",
+ chip->cs, chip->ahb_window_size >> 20);
+
+ /* Define the default IO read settings */
+ ctl_val = readl(chip->ctl) & ~CTRL_IO_CMD_MASK;
+ ctl_val |= aspeed_spi_get_io_mode(op) |
+ op->cmd.opcode << CTRL_COMMAND_SHIFT |
+ CTRL_IO_DUMMY_SET(op->dummy.nbytes / op->dummy.buswidth) |
+ CTRL_IO_MODE_READ;
+
+ /* Tune 4BYTE address mode */
+ if (op->addr.nbytes) {
+ u32 addr_mode = readl(aspi->regs + CE_CTRL_REG);
+
+ if (op->addr.nbytes == 4)
+ addr_mode |= (0x11 << chip->cs);
+ else
+ addr_mode &= ~(0x11 << chip->cs);
+ writel(addr_mode, aspi->regs + CE_CTRL_REG);
+
+ /* AST2400 SPI controller sets 4BYTE address mode in
+ * CE0 Control Register
+ */
+ if (op->addr.nbytes == 4 && chip->aspi->data == &ast2400_spi_data)
+ ctl_val |= CTRL_IO_ADDRESS_4B;
+ }
+
+ /* READ mode is the controller default setting */
+ chip->ctl_val[ASPEED_SPI_READ] = ctl_val;
+ writel(chip->ctl_val[ASPEED_SPI_READ], chip->ctl);
+
+ ret = aspeed_spi_do_calibration(chip);
+
+ dev_info(aspi->dev, "CE%d read buswidth:%d [0x%08x]\n",
+ chip->cs, op->data.buswidth, chip->ctl_val[ASPEED_SPI_READ]);
+
+ return ret;
+}
+
+static ssize_t aspeed_spi_dirmap_read(struct spi_mem_dirmap_desc *desc,
+ u64 offset, size_t len, void *buf)
+{
+ struct aspeed_spi *aspi = spi_controller_get_devdata(desc->mem->spi->master);
+ struct aspeed_spi_chip *chip = &aspi->chips[desc->mem->spi->chip_select];
+
+ /* Switch to USER command mode if mapping window is too small */
+ if (chip->ahb_window_size < offset + len) {
+ int ret;
+
+ ret = aspeed_spi_read_user(chip, &desc->info.op_tmpl, offset, len, buf);
+ if (ret < 0)
+ return ret;
+ } else {
+ memcpy_fromio(buf, chip->ahb_base + offset, len);
+ }
+
+ return len;
+}
+
+static const struct spi_controller_mem_ops aspeed_spi_mem_ops = {
+ .supports_op = aspeed_spi_supports_op,
+ .exec_op = aspeed_spi_exec_op,
+ .get_name = aspeed_spi_get_name,
+ .dirmap_create = aspeed_spi_dirmap_create,
+ .dirmap_read = aspeed_spi_dirmap_read,
+};
+
+static void aspeed_spi_chip_set_type(struct aspeed_spi *aspi, unsigned int cs, int type)
+{
+ u32 reg;
+
+ reg = readl(aspi->regs + CONFIG_REG);
+ reg &= ~(0x3 << (cs * 2));
+ reg |= type << (cs * 2);
+ writel(reg, aspi->regs + CONFIG_REG);
+}
+
+static void aspeed_spi_chip_enable(struct aspeed_spi *aspi, unsigned int cs, bool enable)
+{
+ u32 we_bit = BIT(aspi->data->we0 + cs);
+ u32 reg = readl(aspi->regs + CONFIG_REG);
+
+ if (enable)
+ reg |= we_bit;
+ else
+ reg &= ~we_bit;
+ writel(reg, aspi->regs + CONFIG_REG);
+}
+
+static int aspeed_spi_setup(struct spi_device *spi)
+{
+ struct aspeed_spi *aspi = spi_controller_get_devdata(spi->master);
+ const struct aspeed_spi_data *data = aspi->data;
+ unsigned int cs = spi->chip_select;
+ struct aspeed_spi_chip *chip = &aspi->chips[cs];
+
+ chip->aspi = aspi;
+ chip->cs = cs;
+ chip->ctl = aspi->regs + data->ctl0 + cs * 4;
+
+ /* The driver only supports SPI type flash */
+ if (data->hastype)
+ aspeed_spi_chip_set_type(aspi, cs, CONFIG_TYPE_SPI);
+
+ if (aspeed_spi_chip_set_default_window(chip) < 0) {
+ dev_warn(aspi->dev, "CE%d window invalid", cs);
+ return -EINVAL;
+ }
+
+ aspeed_spi_chip_enable(aspi, cs, true);
+
+ chip->ctl_val[ASPEED_SPI_BASE] = CTRL_CE_STOP_ACTIVE | CTRL_IO_MODE_USER;
+
+ dev_dbg(aspi->dev, "CE%d setup done\n", cs);
+ return 0;
+}
+
+static void aspeed_spi_cleanup(struct spi_device *spi)
+{
+ struct aspeed_spi *aspi = spi_controller_get_devdata(spi->master);
+ unsigned int cs = spi->chip_select;
+
+ aspeed_spi_chip_enable(aspi, cs, false);
+
+ dev_dbg(aspi->dev, "CE%d cleanup done\n", cs);
+}
+
+static void aspeed_spi_enable(struct aspeed_spi *aspi, bool enable)
+{
+ int cs;
+
+ for (cs = 0; cs < aspi->data->max_cs; cs++)
+ aspeed_spi_chip_enable(aspi, cs, enable);
+}
+
+static int aspeed_spi_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct aspeed_spi_data *data;
+ struct spi_controller *ctlr;
+ struct aspeed_spi *aspi;
+ struct resource *res;
+ int ret;
+
+ data = of_device_get_match_data(&pdev->dev);
+ if (!data)
+ return -ENODEV;
+
+ ctlr = devm_spi_alloc_master(dev, sizeof(*aspi));
+ if (!ctlr)
+ return -ENOMEM;
+
+ aspi = spi_controller_get_devdata(ctlr);
+ platform_set_drvdata(pdev, aspi);
+ aspi->data = data;
+ aspi->dev = dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ aspi->regs = devm_ioremap_resource(dev, res);
+ if (IS_ERR(aspi->regs)) {
+ dev_err(dev, "missing AHB register window\n");
+ return PTR_ERR(aspi->regs);
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ aspi->ahb_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(aspi->ahb_base)) {
+ dev_err(dev, "missing AHB mapping window\n");
+ return PTR_ERR(aspi->ahb_base);
+ }
+
+ aspi->ahb_window_size = resource_size(res);
+ aspi->ahb_base_phy = res->start;
+
+ aspi->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(aspi->clk)) {
+ dev_err(dev, "missing clock\n");
+ return PTR_ERR(aspi->clk);
+ }
+
+ aspi->clk_freq = clk_get_rate(aspi->clk);
+ if (!aspi->clk_freq) {
+ dev_err(dev, "invalid clock\n");
+ return -EINVAL;
+ }
+
+ ret = clk_prepare_enable(aspi->clk);
+ if (ret) {
+ dev_err(dev, "can not enable the clock\n");
+ return ret;
+ }
+
+ /* IRQ is for DMA, which the driver doesn't support yet */
+
+ ctlr->mode_bits = SPI_RX_DUAL | SPI_TX_DUAL | data->mode_bits;
+ ctlr->bus_num = pdev->id;
+ ctlr->mem_ops = &aspeed_spi_mem_ops;
+ ctlr->setup = aspeed_spi_setup;
+ ctlr->cleanup = aspeed_spi_cleanup;
+ ctlr->num_chipselect = data->max_cs;
+ ctlr->dev.of_node = dev->of_node;
+
+ ret = devm_spi_register_controller(dev, ctlr);
+ if (ret) {
+ dev_err(&pdev->dev, "spi_register_controller failed\n");
+ goto disable_clk;
+ }
+ return 0;
+
+disable_clk:
+ clk_disable_unprepare(aspi->clk);
+ return ret;
+}
+
+static int aspeed_spi_remove(struct platform_device *pdev)
+{
+ struct aspeed_spi *aspi = platform_get_drvdata(pdev);
+
+ aspeed_spi_enable(aspi, false);
+ clk_disable_unprepare(aspi->clk);
+ return 0;
+}
+
+/*
+ * AHB mappings
+ */
+
+/*
+ * The Segment Registers of the AST2400 and AST2500 use a 8MB unit.
+ * The address range is encoded with absolute addresses in the overall
+ * mapping window.
+ */
+static u32 aspeed_spi_segment_start(struct aspeed_spi *aspi, u32 reg)
+{
+ return ((reg >> 16) & 0xFF) << 23;
+}
+
+static u32 aspeed_spi_segment_end(struct aspeed_spi *aspi, u32 reg)
+{
+ return ((reg >> 24) & 0xFF) << 23;
+}
+
+static u32 aspeed_spi_segment_reg(struct aspeed_spi *aspi, u32 start, u32 end)
+{
+ return (((start >> 23) & 0xFF) << 16) | (((end >> 23) & 0xFF) << 24);
+}
+
+/*
+ * The Segment Registers of the AST2600 use a 1MB unit. The address
+ * range is encoded with offsets in the overall mapping window.
+ */
+
+#define AST2600_SEG_ADDR_MASK 0x0ff00000
+
+static u32 aspeed_spi_segment_ast2600_start(struct aspeed_spi *aspi,
+ u32 reg)
+{
+ u32 start_offset = (reg << 16) & AST2600_SEG_ADDR_MASK;
+
+ return aspi->ahb_base_phy + start_offset;
+}
+
+static u32 aspeed_spi_segment_ast2600_end(struct aspeed_spi *aspi,
+ u32 reg)
+{
+ u32 end_offset = reg & AST2600_SEG_ADDR_MASK;
+
+ /* segment is disabled */
+ if (!end_offset)
+ return aspi->ahb_base_phy;
+
+ return aspi->ahb_base_phy + end_offset + 0x100000;
+}
+
+static u32 aspeed_spi_segment_ast2600_reg(struct aspeed_spi *aspi,
+ u32 start, u32 end)
+{
+ /* disable zero size segments */
+ if (start == end)
+ return 0;
+
+ return ((start & AST2600_SEG_ADDR_MASK) >> 16) |
+ ((end - 1) & AST2600_SEG_ADDR_MASK);
+}
+
+/*
+ * Read timing compensation sequences
+ */
+
+#define CALIBRATE_BUF_SIZE SZ_16K
+
+static bool aspeed_spi_check_reads(struct aspeed_spi_chip *chip,
+ const u8 *golden_buf, u8 *test_buf)
+{
+ int i;
+
+ for (i = 0; i < 10; i++) {
+ memcpy_fromio(test_buf, chip->ahb_base, CALIBRATE_BUF_SIZE);
+ if (memcmp(test_buf, golden_buf, CALIBRATE_BUF_SIZE) != 0) {
+#if defined(VERBOSE_DEBUG)
+ print_hex_dump_bytes(DEVICE_NAME " fail: ", DUMP_PREFIX_NONE,
+ test_buf, 0x100);
+#endif
+ return false;
+ }
+ }
+ return true;
+}
+
+#define FREAD_TPASS(i) (((i) / 2) | (((i) & 1) ? 0 : 8))
+
+/*
+ * The timing register is shared by all devices. Only update for CE0.
+ */
+static int aspeed_spi_calibrate(struct aspeed_spi_chip *chip, u32 hdiv,
+ const u8 *golden_buf, u8 *test_buf)
+{
+ struct aspeed_spi *aspi = chip->aspi;
+ const struct aspeed_spi_data *data = aspi->data;
+ int i;
+ int good_pass = -1, pass_count = 0;
+ u32 shift = (hdiv - 1) << 2;
+ u32 mask = ~(0xfu << shift);
+ u32 fread_timing_val = 0;
+
+ /* Try HCLK delay 0..5, each one with/without delay and look for a
+ * good pair.
+ */
+ for (i = 0; i < 12; i++) {
+ bool pass;
+
+ if (chip->cs == 0) {
+ fread_timing_val &= mask;
+ fread_timing_val |= FREAD_TPASS(i) << shift;
+ writel(fread_timing_val, aspi->regs + data->timing);
+ }
+ pass = aspeed_spi_check_reads(chip, golden_buf, test_buf);
+ dev_dbg(aspi->dev,
+ " * [%08x] %d HCLK delay, %dns DI delay : %s",
+ fread_timing_val, i / 2, (i & 1) ? 0 : 4,
+ pass ? "PASS" : "FAIL");
+ if (pass) {
+ pass_count++;
+ if (pass_count == 3) {
+ good_pass = i - 1;
+ break;
+ }
+ } else {
+ pass_count = 0;
+ }
+ }
+
+ /* No good setting for this frequency */
+ if (good_pass < 0)
+ return -1;
+
+ /* We have at least one pass of margin, let's use first pass */
+ if (chip->cs == 0) {
+ fread_timing_val &= mask;
+ fread_timing_val |= FREAD_TPASS(good_pass) << shift;
+ writel(fread_timing_val, aspi->regs + data->timing);
+ }
+ dev_dbg(aspi->dev, " * -> good is pass %d [0x%08x]",
+ good_pass, fread_timing_val);
+ return 0;
+}
+
+static bool aspeed_spi_check_calib_data(const u8 *test_buf, u32 size)
+{
+ const u32 *tb32 = (const u32 *)test_buf;
+ u32 i, cnt = 0;
+
+ /* We check if we have enough words that are neither all 0
+ * nor all 1's so the calibration can be considered valid.
+ *
+ * I use an arbitrary threshold for now of 64
+ */
+ size >>= 2;
+ for (i = 0; i < size; i++) {
+ if (tb32[i] != 0 && tb32[i] != 0xffffffff)
+ cnt++;
+ }
+ return cnt >= 64;
+}
+
+static const u32 aspeed_spi_hclk_divs[] = {
+ 0xf, /* HCLK */
+ 0x7, /* HCLK/2 */
+ 0xe, /* HCLK/3 */
+ 0x6, /* HCLK/4 */
+ 0xd, /* HCLK/5 */
+};
+
+#define ASPEED_SPI_HCLK_DIV(i) \
+ (aspeed_spi_hclk_divs[(i) - 1] << CTRL_FREQ_SEL_SHIFT)
+
+static int aspeed_spi_do_calibration(struct aspeed_spi_chip *chip)
+{
+ struct aspeed_spi *aspi = chip->aspi;
+ const struct aspeed_spi_data *data = aspi->data;
+ u32 ahb_freq = aspi->clk_freq;
+ u32 max_freq = chip->clk_freq;
+ u32 ctl_val;
+ u8 *golden_buf = NULL;
+ u8 *test_buf = NULL;
+ int i, rc, best_div = -1;
+
+ dev_dbg(aspi->dev, "calculate timing compensation - AHB freq: %d MHz",
+ ahb_freq / 1000000);
+
+ /*
+ * use the related low frequency to get check calibration data
+ * and get golden data.
+ */
+ ctl_val = chip->ctl_val[ASPEED_SPI_READ] & data->hclk_mask;
+ writel(ctl_val, chip->ctl);
+
+ test_buf = kzalloc(CALIBRATE_BUF_SIZE * 2, GFP_KERNEL);
+ if (!test_buf)
+ return -ENOMEM;
+
+ golden_buf = test_buf + CALIBRATE_BUF_SIZE;
+
+ memcpy_fromio(golden_buf, chip->ahb_base, CALIBRATE_BUF_SIZE);
+ if (!aspeed_spi_check_calib_data(golden_buf, CALIBRATE_BUF_SIZE)) {
+ dev_info(aspi->dev, "Calibration area too uniform, using low speed");
+ goto no_calib;
+ }
+
+#if defined(VERBOSE_DEBUG)
+ print_hex_dump_bytes(DEVICE_NAME " good: ", DUMP_PREFIX_NONE,
+ golden_buf, 0x100);
+#endif
+
+ /* Now we iterate the HCLK dividers until we find our breaking point */
+ for (i = ARRAY_SIZE(aspeed_spi_hclk_divs); i > data->hdiv_max - 1; i--) {
+ u32 tv, freq;
+
+ freq = ahb_freq / i;
+ if (freq > max_freq)
+ continue;
+
+ /* Set the timing */
+ tv = chip->ctl_val[ASPEED_SPI_READ] | ASPEED_SPI_HCLK_DIV(i);
+ writel(tv, chip->ctl);
+ dev_dbg(aspi->dev, "Trying HCLK/%d [%08x] ...", i, tv);
+ rc = data->calibrate(chip, i, golden_buf, test_buf);
+ if (rc == 0)
+ best_div = i;
+ }
+
+ /* Nothing found ? */
+ if (best_div < 0) {
+ dev_warn(aspi->dev, "No good frequency, using dumb slow");
+ } else {
+ dev_dbg(aspi->dev, "Found good read timings at HCLK/%d", best_div);
+
+ /* Record the freq */
+ for (i = 0; i < ASPEED_SPI_MAX; i++)
+ chip->ctl_val[i] = (chip->ctl_val[i] & data->hclk_mask) |
+ ASPEED_SPI_HCLK_DIV(best_div);
+ }
+
+no_calib:
+ writel(chip->ctl_val[ASPEED_SPI_READ], chip->ctl);
+ kfree(test_buf);
+ return 0;
+}
+
+#define TIMING_DELAY_DI BIT(3)
+#define TIMING_DELAY_HCYCLE_MAX 5
+#define TIMING_REG_AST2600(chip) \
+ ((chip)->aspi->regs + (chip)->aspi->data->timing + \
+ (chip)->cs * 4)
+
+static int aspeed_spi_ast2600_calibrate(struct aspeed_spi_chip *chip, u32 hdiv,
+ const u8 *golden_buf, u8 *test_buf)
+{
+ struct aspeed_spi *aspi = chip->aspi;
+ int hcycle;
+ u32 shift = (hdiv - 2) << 3;
+ u32 mask = ~(0xfu << shift);
+ u32 fread_timing_val = 0;
+
+ for (hcycle = 0; hcycle <= TIMING_DELAY_HCYCLE_MAX; hcycle++) {
+ int delay_ns;
+ bool pass = false;
+
+ fread_timing_val &= mask;
+ fread_timing_val |= hcycle << shift;
+
+ /* no DI input delay first */
+ writel(fread_timing_val, TIMING_REG_AST2600(chip));
+ pass = aspeed_spi_check_reads(chip, golden_buf, test_buf);
+ dev_dbg(aspi->dev,
+ " * [%08x] %d HCLK delay, DI delay none : %s",
+ fread_timing_val, hcycle, pass ? "PASS" : "FAIL");
+ if (pass)
+ return 0;
+
+ /* Add DI input delays */
+ fread_timing_val &= mask;
+ fread_timing_val |= (TIMING_DELAY_DI | hcycle) << shift;
+
+ for (delay_ns = 0; delay_ns < 0x10; delay_ns++) {
+ fread_timing_val &= ~(0xf << (4 + shift));
+ fread_timing_val |= delay_ns << (4 + shift);
+
+ writel(fread_timing_val, TIMING_REG_AST2600(chip));
+ pass = aspeed_spi_check_reads(chip, golden_buf, test_buf);
+ dev_dbg(aspi->dev,
+ " * [%08x] %d HCLK delay, DI delay %d.%dns : %s",
+ fread_timing_val, hcycle, (delay_ns + 1) / 2,
+ (delay_ns + 1) & 1 ? 5 : 5, pass ? "PASS" : "FAIL");
+ /*
+ * TODO: This is optimistic. We should look
+ * for a working interval and save the middle
+ * value in the read timing register.
+ */
+ if (pass)
+ return 0;
+ }
+ }
+
+ /* No good setting for this frequency */
+ return -1;
+}
+
+/*
+ * Platform definitions
+ */
+static const struct aspeed_spi_data ast2400_fmc_data = {
+ .max_cs = 5,
+ .hastype = true,
+ .we0 = 16,
+ .ctl0 = CE0_CTRL_REG,
+ .timing = CE0_TIMING_COMPENSATION_REG,
+ .hclk_mask = 0xfffff0ff,
+ .hdiv_max = 1,
+ .calibrate = aspeed_spi_calibrate,
+ .segment_start = aspeed_spi_segment_start,
+ .segment_end = aspeed_spi_segment_end,
+ .segment_reg = aspeed_spi_segment_reg,
+};
+
+static const struct aspeed_spi_data ast2400_spi_data = {
+ .max_cs = 1,
+ .hastype = false,
+ .we0 = 0,
+ .ctl0 = 0x04,
+ .timing = 0x14,
+ .hclk_mask = 0xfffff0ff,
+ .hdiv_max = 1,
+ .calibrate = aspeed_spi_calibrate,
+ /* No segment registers */
+};
+
+static const struct aspeed_spi_data ast2500_fmc_data = {
+ .max_cs = 3,
+ .hastype = true,
+ .we0 = 16,
+ .ctl0 = CE0_CTRL_REG,
+ .timing = CE0_TIMING_COMPENSATION_REG,
+ .hclk_mask = 0xffffd0ff,
+ .hdiv_max = 1,
+ .calibrate = aspeed_spi_calibrate,
+ .segment_start = aspeed_spi_segment_start,
+ .segment_end = aspeed_spi_segment_end,
+ .segment_reg = aspeed_spi_segment_reg,
+};
+
+static const struct aspeed_spi_data ast2500_spi_data = {
+ .max_cs = 2,
+ .hastype = false,
+ .we0 = 16,
+ .ctl0 = CE0_CTRL_REG,
+ .timing = CE0_TIMING_COMPENSATION_REG,
+ .hclk_mask = 0xffffd0ff,
+ .hdiv_max = 1,
+ .calibrate = aspeed_spi_calibrate,
+ .segment_start = aspeed_spi_segment_start,
+ .segment_end = aspeed_spi_segment_end,
+ .segment_reg = aspeed_spi_segment_reg,
+};
+
+static const struct aspeed_spi_data ast2600_fmc_data = {
+ .max_cs = 3,
+ .hastype = false,
+ .mode_bits = SPI_RX_QUAD | SPI_RX_QUAD,
+ .we0 = 16,
+ .ctl0 = CE0_CTRL_REG,
+ .timing = CE0_TIMING_COMPENSATION_REG,
+ .hclk_mask = 0xf0fff0ff,
+ .hdiv_max = 2,
+ .calibrate = aspeed_spi_ast2600_calibrate,
+ .segment_start = aspeed_spi_segment_ast2600_start,
+ .segment_end = aspeed_spi_segment_ast2600_end,
+ .segment_reg = aspeed_spi_segment_ast2600_reg,
+};
+
+static const struct aspeed_spi_data ast2600_spi_data = {
+ .max_cs = 2,
+ .hastype = false,
+ .mode_bits = SPI_RX_QUAD | SPI_RX_QUAD,
+ .we0 = 16,
+ .ctl0 = CE0_CTRL_REG,
+ .timing = CE0_TIMING_COMPENSATION_REG,
+ .hclk_mask = 0xf0fff0ff,
+ .hdiv_max = 2,
+ .calibrate = aspeed_spi_ast2600_calibrate,
+ .segment_start = aspeed_spi_segment_ast2600_start,
+ .segment_end = aspeed_spi_segment_ast2600_end,
+ .segment_reg = aspeed_spi_segment_ast2600_reg,
+};
+
+static const struct of_device_id aspeed_spi_matches[] = {
+ { .compatible = "aspeed,ast2400-fmc", .data = &ast2400_fmc_data },
+ { .compatible = "aspeed,ast2400-spi", .data = &ast2400_spi_data },
+ { .compatible = "aspeed,ast2500-fmc", .data = &ast2500_fmc_data },
+ { .compatible = "aspeed,ast2500-spi", .data = &ast2500_spi_data },
+ { .compatible = "aspeed,ast2600-fmc", .data = &ast2600_fmc_data },
+ { .compatible = "aspeed,ast2600-spi", .data = &ast2600_spi_data },
+ { }
+};
+MODULE_DEVICE_TABLE(of, aspeed_spi_matches);
+
+static struct platform_driver aspeed_spi_driver = {
+ .probe = aspeed_spi_probe,
+ .remove = aspeed_spi_remove,
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = aspeed_spi_matches,
+ }
+};
+
+module_platform_driver(aspeed_spi_driver);
+
+MODULE_DESCRIPTION("ASPEED Static Memory Controller Driver");
+MODULE_AUTHOR("Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>");
+MODULE_AUTHOR("Cedric Le Goater <clg@kaod.org>");
+MODULE_LICENSE("GPL v2");