imx8mp: power-domain: Expose high performance PLL clock

Expose the high performance PLL as clock framework clock, so the
PCIe PHY can use it when there is no external refclock provided.

Inspired from counterpart Linux kernel v6.8-rc3 driver:
drivers/pmdomain/imx/imx8mp-blk-ctrl.c. Use last Linux kernel driver
reference commit 7476ddfd36ac ("pmdomain: imx8mp-blk-ctrl: Convert to
platform remove callback returning void").

Tested-by: Tim Harvey <tharvey@gateworks.com> #imx8mp-venice*
Tested-by: Adam Ford <aford173@gmail.com> #imx8mp-beacon-kit
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/drivers/power/domain/imx8mp-hsiomix.c b/drivers/power/domain/imx8mp-hsiomix.c
index d3b0c11..6188a04 100644
--- a/drivers/power/domain/imx8mp-hsiomix.c
+++ b/drivers/power/domain/imx8mp-hsiomix.c
@@ -6,9 +6,15 @@
 #include <common.h>
 #include <asm/io.h>
 #include <clk.h>
+#include <clk-uclass.h>
 #include <dm.h>
 #include <dm/device.h>
 #include <dm/device_compat.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/iopoll.h>
 #include <power-domain-uclass.h>
 
 #include <dt-bindings/power/imx8mp-power.h>
@@ -18,6 +24,15 @@
 #define  USB_CLOCK_MODULE_EN	BIT(1)
 #define  PCIE_PHY_APB_RST	BIT(4)
 #define  PCIE_PHY_INIT_RST	BIT(5)
+#define GPR_REG1		0x4
+#define  PLL_LOCK		BIT(13)
+#define GPR_REG2		0x8
+#define  P_PLL_MASK		GENMASK(5, 0)
+#define  M_PLL_MASK		GENMASK(15, 6)
+#define  S_PLL_MASK		GENMASK(18, 16)
+#define GPR_REG3		0xc
+#define  PLL_CKE		BIT(17)
+#define  PLL_RST		BIT(31)
 
 struct imx8mp_hsiomix_priv {
 	void __iomem *base;
@@ -123,6 +138,67 @@ static int imx8mp_hsiomix_of_xlate(struct power_domain *power_domain,
 	return 0;
 }
 
+static int hsio_pll_clk_enable(struct clk *clk)
+{
+	void *base = (void *)dev_get_driver_data(clk->dev);
+	u32 val;
+	int ret;
+
+	/* Setup HSIO PLL as 100 MHz output clock */
+	clrsetbits_le32(base + GPR_REG2,
+			P_PLL_MASK | M_PLL_MASK | S_PLL_MASK,
+			FIELD_PREP(P_PLL_MASK, 12) |
+			FIELD_PREP(M_PLL_MASK, 800) |
+			FIELD_PREP(S_PLL_MASK, 4));
+
+	/* de-assert PLL reset */
+	setbits_le32(base + GPR_REG3, PLL_RST);
+
+	/* enable PLL */
+	setbits_le32(base + GPR_REG3, PLL_CKE);
+
+	/* Check if PLL is locked */
+	ret = readl_poll_sleep_timeout(base + GPR_REG1, val,
+				       val & PLL_LOCK, 10, 100000);
+	if (ret)
+		dev_err(clk->dev, "failed to lock HSIO PLL\n");
+
+	return ret;
+}
+
+static int hsio_pll_clk_disable(struct clk *clk)
+{
+	void *base = (void *)dev_get_driver_data(clk->dev);
+
+	clrbits_le32(base + GPR_REG3, PLL_CKE | PLL_RST);
+
+	return 0;
+}
+
+static const struct clk_ops hsio_pll_clk_ops = {
+	.enable = hsio_pll_clk_enable,
+	.disable = hsio_pll_clk_disable,
+};
+
+U_BOOT_DRIVER(hsio_pll) = {
+	.name = "hsio-pll",
+	.id = UCLASS_CLK,
+	.ops = &hsio_pll_clk_ops,
+};
+
+int imx8mp_hsiomix_bind(struct udevice *dev)
+{
+	struct driver *drv;
+
+	drv = lists_driver_lookup_name("hsio-pll");
+	if (!drv)
+		return -ENOENT;
+
+	return device_bind_with_driver_data(dev, drv, "hsio-pll",
+					    (ulong)dev_read_addr_ptr(dev),
+					    dev_ofnode(dev), NULL);
+}
+
 static int imx8mp_hsiomix_probe(struct udevice *dev)
 {
 	struct imx8mp_hsiomix_priv *priv = dev_get_priv(dev);
@@ -193,6 +269,7 @@ U_BOOT_DRIVER(imx8mp_hsiomix) = {
 	.id		= UCLASS_POWER_DOMAIN,
 	.of_match	= imx8mp_hsiomix_ids,
 	.probe		= imx8mp_hsiomix_probe,
+	.bind		= imx8mp_hsiomix_bind,
 	.priv_auto	= sizeof(struct imx8mp_hsiomix_priv),
 	.ops		= &imx8mp_hsiomix_ops,
 };