[PATCH v2 4/4] spi: aspeed: Add support for the AST2700 SPI controller

[Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>]

Extend the driver to support the AST2700 SPI controller. Compared to
AST2600, AST2700 has the following characteristics:
 - A 64-bit memory address space.
 - A 64KB address decoding unit.
 - Segment registers now use (start <= range < end) semantics,
   which differs slightly from (start <= range <= end) in AST2600.
 - Known issues related to address decoding range registers have been
   resolved, and the decoding range is now 1GB, which is sufficient.
   Therefore, the adjust_window callback is no longer required on AST2700
   for range adjustment and bug fixes.
 - The SPI clock divider method and timing calibration logic remain
   unchanged from AST2600.

Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
---
 drivers/spi/spi-aspeed-smc.c | 71 ++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/drivers/spi/spi-aspeed-smc.c b/drivers/spi/spi-aspeed-smc.c
index d1a8bdf6d540..db3e096f2eb0 100644
--- a/drivers/spi/spi-aspeed-smc.c
+++ b/drivers/spi/spi-aspeed-smc.c
@@ -985,6 +985,41 @@ static u32 aspeed_spi_segment_ast2600_reg(struct aspeed_spi *aspi,
 		((end - 1) & AST2600_SEG_ADDR_MASK);
 }
 
+/* The Segment Registers of the AST2700 use a 64KB unit. */
+#define AST2700_SEG_ADDR_MASK 0x7fff0000
+
+static phys_addr_t aspeed_spi_segment_ast2700_start(struct aspeed_spi *aspi,
+						    u32 reg)
+{
+	u64 start_offset = (reg << 16) & AST2700_SEG_ADDR_MASK;
+
+	if (!start_offset)
+		return aspi->ahb_base_phy;
+
+	return aspi->ahb_base_phy + start_offset;
+}
+
+static phys_addr_t aspeed_spi_segment_ast2700_end(struct aspeed_spi *aspi,
+						  u32 reg)
+{
+	u64 end_offset = reg & AST2700_SEG_ADDR_MASK;
+
+	if (!end_offset)
+		return aspi->ahb_base_phy;
+
+	return aspi->ahb_base_phy + end_offset;
+}
+
+static u32 aspeed_spi_segment_ast2700_reg(struct aspeed_spi *aspi,
+					  phys_addr_t start, phys_addr_t end)
+{
+	if (start == end)
+		return 0;
+
+	return (u32)(((start & AST2700_SEG_ADDR_MASK) >> 16) |
+		     (end & AST2700_SEG_ADDR_MASK));
+}
+
 /*
  * Read timing compensation sequences
  */
@@ -1511,6 +1546,40 @@ static const struct aspeed_spi_data ast2600_spi_data = {
 	.adjust_window = aspeed_adjust_window_ast2600,
 };
 
+static const struct aspeed_spi_data ast2700_fmc_data = {
+	.max_cs	       = 3,
+	.hastype       = false,
+	.mode_bits     = SPI_RX_QUAD | SPI_TX_QUAD,
+	.we0	       = 16,
+	.ctl0	       = CE0_CTRL_REG,
+	.timing	       = CE0_TIMING_COMPENSATION_REG,
+	.hclk_mask     = 0xf0fff0ff,
+	.hdiv_max      = 2,
+	.min_window_size = 0x10000,
+	.get_clk_div   = aspeed_get_clk_div_ast2600,
+	.calibrate     = aspeed_spi_ast2600_calibrate,
+	.segment_start = aspeed_spi_segment_ast2700_start,
+	.segment_end   = aspeed_spi_segment_ast2700_end,
+	.segment_reg   = aspeed_spi_segment_ast2700_reg,
+};
+
+static const struct aspeed_spi_data ast2700_spi_data = {
+	.max_cs	       = 2,
+	.hastype       = false,
+	.mode_bits     = SPI_RX_QUAD | SPI_TX_QUAD,
+	.we0	       = 16,
+	.ctl0	       = CE0_CTRL_REG,
+	.timing	       = CE0_TIMING_COMPENSATION_REG,
+	.hclk_mask     = 0xf0fff0ff,
+	.hdiv_max      = 2,
+	.min_window_size = 0x10000,
+	.get_clk_div   = aspeed_get_clk_div_ast2600,
+	.calibrate     = aspeed_spi_ast2600_calibrate,
+	.segment_start = aspeed_spi_segment_ast2700_start,
+	.segment_end   = aspeed_spi_segment_ast2700_end,
+	.segment_reg   = aspeed_spi_segment_ast2700_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 },
@@ -1518,6 +1587,8 @@ static const struct of_device_id aspeed_spi_matches[] = {
 	{ .compatible = "aspeed,ast2500-spi", .data = &ast2500_spi_data },
 	{ .compatible = "aspeed,ast2600-fmc", .data = &ast2600_fmc_data },
 	{ .compatible = "aspeed,ast2600-spi", .data = &ast2600_spi_data },
+	{ .compatible = "aspeed,ast2700-fmc", .data = &ast2700_fmc_data },
+	{ .compatible = "aspeed,ast2700-spi", .data = &ast2700_spi_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, aspeed_spi_matches);
-- 
2.34.1