1 files changed, 88 insertions, 0 deletions

diff --git a/drivers/spi/spi-aspeed-smc.c b/drivers/spi/spi-aspeed-smc.c
index 50cc7bd7ba3e..0aff42e20b8d 100644
--- a/drivers/spi/spi-aspeed-smc.c
+++ b/drivers/spi/spi-aspeed-smc.c
@@ -411,6 +411,92 @@ static int aspeed_spi_chip_set_default_window(struct aspeed_spi_chip *chip)
 	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 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;
+
+	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_dirmap_create(struct spi_mem_dirmap_desc *desc)
 {
 	struct aspeed_spi *aspi = spi_controller_get_devdata(desc->mem->spi->master);
@@ -425,6 +511,8 @@ static int aspeed_spi_dirmap_create(struct spi_mem_dirmap_desc *desc)
 	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);