clk: fsl-sai: Add i.MX8M support with 8 byte register offset

The i.MX8M/Mini/Nano/Plus variant of the SAI IP has control registers
shifted by +8 bytes and requires additional bus clock. Add support for
the i.MX8M variant of the IP with this register shift and additional
clock.

Reviewed-by: Brian Masney <bmasney@redhat.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Marek Vasut <marex@nabladev.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: Marek Vasut

drivers/clk/Kconfig

@@ -255,7 +255,7 @@ config COMMON_CLK_FSL_FLEXSPI
 
 config COMMON_CLK_FSL_SAI
 	bool "Clock driver for BCLK of Freescale SAI cores"
-	depends on ARCH_LAYERSCAPE || COMPILE_TEST
+	depends on ARCH_LAYERSCAPE || ARCH_MXC || COMPILE_TEST
 	help
 	  This driver supports the Freescale SAI (Synchronous Audio Interface)
 	  to be used as a generic clock output. Some SoCs have restrictions

drivers/clk/clk-fsl-sai.c

@@ -6,6 +6,7 @@
  */
 
 #include <linux/clk-provider.h>
+#include <linux/clk.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -20,6 +21,10 @@
 #define CR2_DIV_SHIFT	0
 #define CR2_DIV_WIDTH	8
 
+struct fsl_sai_data {
+	unsigned int	offset;	/* Register offset */
+};
+
 struct fsl_sai_clk {
 	struct clk_divider div;
 	struct clk_gate gate;
@@ -29,8 +34,10 @@ struct fsl_sai_clk {
 static int fsl_sai_clk_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	const struct fsl_sai_data *data = device_get_match_data(dev);
 	struct fsl_sai_clk *sai_clk;
 	struct clk_parent_data pdata = { .index = 0 };
+	struct clk *clk_bus;
 	void __iomem *base;
 	struct clk_hw *hw;
 
@@ -42,19 +49,23 @@ static int fsl_sai_clk_probe(struct platform_device *pdev)
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 
+	clk_bus = devm_clk_get_optional_enabled(dev, "bus");
+	if (IS_ERR(clk_bus))
+		return PTR_ERR(clk_bus);
+
 	spin_lock_init(&sai_clk->lock);
 
-	sai_clk->gate.reg = base + I2S_CSR;
+	sai_clk->gate.reg = base + data->offset + I2S_CSR;
 	sai_clk->gate.bit_idx = CSR_BCE_BIT;
 	sai_clk->gate.lock = &sai_clk->lock;
 
-	sai_clk->div.reg = base + I2S_CR2;
+	sai_clk->div.reg = base + data->offset + I2S_CR2;
 	sai_clk->div.shift = CR2_DIV_SHIFT;
 	sai_clk->div.width = CR2_DIV_WIDTH;
 	sai_clk->div.lock = &sai_clk->lock;
 
 	/* set clock direction, we are the BCLK master */
-	writel(CR2_BCD, base + I2S_CR2);
+	writel(CR2_BCD, base + data->offset + I2S_CR2);
 
 	hw = devm_clk_hw_register_composite_pdata(dev, dev->of_node->name,
 						  &pdata, 1, NULL, NULL,
@@ -69,8 +80,17 @@ static int fsl_sai_clk_probe(struct platform_device *pdev)
 	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw);
 }
 
+static const struct fsl_sai_data fsl_sai_vf610_data = {
+	.offset	= 0,
+};
+
+static const struct fsl_sai_data fsl_sai_imx8mq_data = {
+	.offset	= 8,
+};
+
 static const struct of_device_id of_fsl_sai_clk_ids[] = {
-	{ .compatible = "fsl,vf610-sai-clock" },
+	{ .compatible = "fsl,vf610-sai-clock", .data = &fsl_sai_vf610_data },
+	{ .compatible = "fsl,imx8mq-sai-clock", .data = &fsl_sai_imx8mq_data },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, of_fsl_sai_clk_ids);