[RFC 3/5] soc: imx: imx8m-blk-ctrl: add i.MX8MQ VPU blk-ctrl

[Adam Ford]

From: Lucas Stach <l.stach at pengutronix.de>

This adds the necessary bits to drive the VPU blk-ctrl on the i.MX8MQ, to
avoid putting more of this functionality into the decoder driver.

Signed-off-by: Lucas Stach <l.stach at pengutronix.de>
---
 drivers/soc/imx/imx8m-blk-ctrl.c | 67 ++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/drivers/soc/imx/imx8m-blk-ctrl.c b/drivers/soc/imx/imx8m-blk-ctrl.c
index 519b3651d1d9..66c879bcc66b 100644
--- a/drivers/soc/imx/imx8m-blk-ctrl.c
+++ b/drivers/soc/imx/imx8m-blk-ctrl.c
@@ -14,6 +14,7 @@
 #include <linux/clk.h>
 
 #include <dt-bindings/power/imx8mm-power.h>
+#include <dt-bindings/power/imx8mq-power.h>
 
 #define BLK_SFT_RSTN	0x0
 #define BLK_CLK_EN	0x4
@@ -498,6 +499,69 @@ static const struct imx8m_blk_ctrl_data imx8mm_disp_blk_ctl_dev_data = {
 	.num_domains = ARRAY_SIZE(imx8mm_disp_blk_ctl_domain_data),
 };
 
+static int imx8mq_vpu_power_notifier(struct notifier_block *nb,
+				     unsigned long action, void *data)
+{
+	struct imx8m_blk_ctrl *bc = container_of(nb, struct imx8m_blk_ctrl,
+						 power_nb);
+
+	if (action != GENPD_NOTIFY_ON && action != GENPD_NOTIFY_PRE_OFF)
+		return NOTIFY_OK;
+
+	/*
+	 * The ADB in the VPUMIX domain has no separate reset and clock
+	 * enable bits, but is ungated and reset together with the VPUs. The
+	 * reset and clock enable inputs to the ADB is a logical OR of the
+	 * VPU bits. To avoid putting a improperly reset decoder on the bus
+	 * while making the ADB work, we release G2 from reset, but only
+	 * enable clocks to G1.
+	 */
+	regmap_update_bits(bc->regmap, BLK_SFT_RSTN, BIT(0) | BIT(1), BIT(0));
+	regmap_set_bits(bc->regmap, BLK_CLK_EN, BIT(1));
+
+	if (action == GENPD_NOTIFY_ON) {
+		/*
+		 * On power up we have no software backchannel to the GPC to
+		 * wait for the ADB handshake to happen, so we just delay for a
+		 * bit. On power down the GPC driver waits for the handshake.
+		 */
+		udelay(5);
+
+		/* set "fuse" bits to enable the VPUs */
+		regmap_set_bits(bc->regmap, 0x8, 0xffffffff);
+		regmap_set_bits(bc->regmap, 0xc, 0xffffffff);
+		regmap_set_bits(bc->regmap, 0x10, 0xffffffff);
+	}
+
+	return NOTIFY_OK;
+}
+
+static const struct imx8m_blk_ctrl_domain_data imx8mq_vpu_blk_ctl_domain_data[] = {
+	[IMX8MQ_VPUBLK_PD_G1] = {
+		.name = "vpublk-g1",
+		.clk_names = (const char *[]){ "g1", },
+		.num_clks = 1,
+		.gpc_name = "g1",
+		.rst_mask = BIT(1),
+		.clk_mask = BIT(1),
+	},
+	[IMX8MQ_VPUBLK_PD_G2] = {
+		.name = "vpublk-g2",
+		.clk_names = (const char *[]){ "g2", },
+		.num_clks = 1,
+		.gpc_name = "g2",
+		.rst_mask = BIT(0),
+		.clk_mask = BIT(0),
+	},
+};
+
+static const struct imx8m_blk_ctrl_data imx8mq_vpu_blk_ctl_dev_data = {
+	.max_reg = 0x14,
+	.power_notifier_fn = imx8mq_vpu_power_notifier,
+	.domains = imx8mq_vpu_blk_ctl_domain_data,
+	.num_domains = ARRAY_SIZE(imx8mq_vpu_blk_ctl_domain_data),
+};
+
 static const struct of_device_id imx8m_blk_ctrl_of_match[] = {
 	{
 		.compatible = "fsl,imx8mm-vpu-blk-ctrl",
@@ -505,6 +569,9 @@ static const struct of_device_id imx8m_blk_ctrl_of_match[] = {
 	}, {
 		.compatible = "fsl,imx8mm-disp-blk-ctrl",
 		.data = &imx8mm_disp_blk_ctl_dev_data
+	} ,{
+		.compatible = "fsl,imx8mq-vpu-blk-ctrl",
+		.data = &imx8mq_vpu_blk_ctl_dev_data
 	} ,{
 		/* Sentinel */
 	}
-- 
2.32.0