[PATCH 4/4] clk: fsl-sai: Add MCLK generation support

[Marek Vasut <marex@denx.de>]

The driver currently supports generating BCLK. There are systems which
require generation of MCLK instead. Register new MCLK clock and handle
clock-cells = <1> to differentiate between BCLK and MCLK. In case of a
legacy system with clock-cells = <0>, the driver behaves as before, i.e.
always returns BCLK.

Signed-off-by: Marek Vasut <marex@denx.de>
---
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Michael Walle <michael@walle.cc>
Cc: Nicolin Chen <nicoleotsuka@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Shengjiu Wang <shengjiu.wang@gmail.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Xiubo Li <Xiubo.Lee@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-sound@vger.kernel.org
---
 drivers/clk/clk-fsl-sai.c | 81 ++++++++++++++++++++++++++++++++-------
 1 file changed, 67 insertions(+), 14 deletions(-)

diff --git a/drivers/clk/clk-fsl-sai.c b/drivers/clk/clk-fsl-sai.c
index 628e53a3a26fa..0f8e2f2662d87 100644
--- a/drivers/clk/clk-fsl-sai.c
+++ b/drivers/clk/clk-fsl-sai.c
@@ -7,6 +7,7 @@
 
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/err.h>
 #include <linux/of.h>
@@ -15,27 +16,44 @@
 
 #define I2S_CSR		0x00
 #define I2S_CR2		0x08
+#define I2S_MCR		0x100
 #define CSR_BCE_BIT	28
+#define CSR_TE_BIT	31
 #define CR2_BCD		BIT(24)
 #define CR2_DIV_SHIFT	0
 #define CR2_DIV_WIDTH	8
+#define MCR_MOE		BIT(30)
 
 struct fsl_sai_clk {
-	struct clk_divider div;
-	struct clk_gate gate;
+	struct clk_divider bclk_div;
+	struct clk_divider mclk_div;
+	struct clk_gate bclk_gate;
+	struct clk_gate mclk_gate;
+	struct clk_hw *bclk_hw;
+	struct clk_hw *mclk_hw;
 	spinlock_t lock;
 };
 
 struct fsl_sai_data {
 	unsigned int	offset;	/* Register offset */
+	bool		have_mclk; /* Have MCLK control */
 };
 
+static struct clk_hw *
+fsl_sai_of_clk_get(struct of_phandle_args *clkspec, void *data)
+{
+	struct fsl_sai_clk *sai_clk = data;
+
+	return clkspec->args[0] ? sai_clk->mclk_hw : sai_clk->bclk_hw;
+}
+
 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 fsl_sai_clk *sai_clk;
+	struct clk *clk_bus;
 	void __iomem *base;
 	struct clk_hw *hw;
 
@@ -47,39 +65,74 @@ static int fsl_sai_clk_probe(struct platform_device *pdev)
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 
+	clk_bus = devm_clk_get_enabled(dev, "bus");
+	if (IS_ERR(clk_bus))
+		return PTR_ERR(clk_bus);
+
 	spin_lock_init(&sai_clk->lock);
 
-	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->bclk_gate.reg = base + data->offset + I2S_CSR;
+	sai_clk->bclk_gate.bit_idx = CSR_BCE_BIT;
+	sai_clk->bclk_gate.lock = &sai_clk->lock;
 
-	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;
+	sai_clk->bclk_div.reg = base + data->offset + I2S_CR2;
+	sai_clk->bclk_div.shift = CR2_DIV_SHIFT;
+	sai_clk->bclk_div.width = CR2_DIV_WIDTH;
+	sai_clk->bclk_div.lock = &sai_clk->lock;
 
 	/* set clock direction, we are the BCLK master */
 	writel(CR2_BCD, base + data->offset + I2S_CR2);
 
-	hw = devm_clk_hw_register_composite_pdata(dev, dev->of_node->name,
+	hw = devm_clk_hw_register_composite_pdata(dev, "BCLK",
 						  &pdata, 1, NULL, NULL,
-						  &sai_clk->div.hw,
+						  &sai_clk->bclk_div.hw,
 						  &clk_divider_ops,
-						  &sai_clk->gate.hw,
+						  &sai_clk->bclk_gate.hw,
 						  &clk_gate_ops,
 						  CLK_SET_RATE_GATE);
 	if (IS_ERR(hw))
 		return PTR_ERR(hw);
 
-	return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, hw);
+	sai_clk->bclk_hw = hw;
+
+	if (data->have_mclk) {
+		sai_clk->mclk_gate.reg = base + data->offset + I2S_CSR;
+		sai_clk->mclk_gate.bit_idx = CSR_TE_BIT;
+		sai_clk->mclk_gate.lock = &sai_clk->lock;
+
+		sai_clk->mclk_div.reg = base + I2S_MCR;
+		sai_clk->mclk_div.shift = CR2_DIV_SHIFT;
+		sai_clk->mclk_div.width = CR2_DIV_WIDTH;
+		sai_clk->mclk_div.lock = &sai_clk->lock;
+
+		pdata.index = 1; /* MCLK1 */
+		hw = devm_clk_hw_register_composite_pdata(dev, "MCLK",
+							  &pdata, 1, NULL, NULL,
+							  &sai_clk->mclk_div.hw,
+							  &clk_divider_ops,
+							  &sai_clk->mclk_gate.hw,
+							  &clk_gate_ops,
+							  CLK_SET_RATE_GATE);
+		if (IS_ERR(hw))
+			return PTR_ERR(hw);
+
+		sai_clk->mclk_hw = hw;
+
+		/* set clock direction, we are the MCLK output */
+		writel(MCR_MOE, base + I2S_MCR);
+	}
+
+	return devm_of_clk_add_hw_provider(dev, fsl_sai_of_clk_get, sai_clk);
 }
 
 static const struct fsl_sai_data fsl_sai_vf610_data = {
 	.offset	= 0,
+	.have_mclk = false,
 };
 
 static const struct fsl_sai_data fsl_sai_imx8mq_data = {
 	.offset	= 8,
+	.have_mclk = true,
 };
 
 static const struct of_device_id of_fsl_sai_clk_ids[] = {
-- 
2.45.2