Various MediaTek SoCs use GPU integration silicon named "MFlexGraphics"
by MediaTek. On the MT8196 and MT6991 SoCs, interacting with this
integration silicon is required to power on the GPU.

This glue silicon is in the form of an embedded microcontroller running
special-purpose firmware, which autonomously adjusts clocks and
regulators.

Implement a driver, modelled as a pmdomain driver with a
set_performance_state operation, to support these SoCs.

The driver also exposes the actual achieved clock rate, as read back
from the MCU, as common clock framework clocks, by acting as a clock
provider as well.

Signed-off-by: Nicolas Frattaroli <[email protected]>
---
 drivers/pmdomain/mediatek/Kconfig            |   16 +
 drivers/pmdomain/mediatek/Makefile           |    1 +
 drivers/pmdomain/mediatek/mtk-mfg-pmdomain.c | 1027 ++++++++++++++++++++++++++
 3 files changed, 1044 insertions(+)

diff --git a/drivers/pmdomain/mediatek/Kconfig 
b/drivers/pmdomain/mediatek/Kconfig
index 
0e34a517ab7d5a867bebaab11c0d866282a15e45..b06aaa9690f08f33519595916b8ea3ad9035fc55
 100644
--- a/drivers/pmdomain/mediatek/Kconfig
+++ b/drivers/pmdomain/mediatek/Kconfig
@@ -26,6 +26,22 @@ config MTK_SCPSYS_PM_DOMAINS
          Control Processor System (SCPSYS) has several power management related
          tasks in the system.
 
+config MTK_MFG_PM_DOMAIN
+       bool "MediaTek MFlexGraphics power domain"
+       default ARCH_MEDIATEK
+       depends on PM
+       depends on OF
+       depends on COMMON_CLK
+       select PM_GENERIC_DOMAINS
+       imply MTK_GPUEB_MBOX
+       help
+         Say y or m here to enable the power domains driver for MediaTek
+         MFlexGraphics. This driver allows for power and frequency control of
+         GPUs on MediaTek SoCs such as the MT8196 or MT6991.
+
+         This driver is required for the Mali GPU to work at all on MT8196 and
+         MT6991.
+
 config AIROHA_CPU_PM_DOMAIN
        tristate "Airoha CPU power domain"
        default ARCH_AIROHA
diff --git a/drivers/pmdomain/mediatek/Makefile 
b/drivers/pmdomain/mediatek/Makefile
index 
18ba92e3c418154e1d428dbc6b59b97b26056d98..b424f1ed867604393b3ff96364855363aedaa40c
 100644
--- a/drivers/pmdomain/mediatek/Makefile
+++ b/drivers/pmdomain/mediatek/Makefile
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_MTK_MFG_PM_DOMAIN)                += mtk-mfg-pmdomain.o
 obj-$(CONFIG_MTK_SCPSYS)               += mtk-scpsys.o
 obj-$(CONFIG_MTK_SCPSYS_PM_DOMAINS)    += mtk-pm-domains.o
 obj-$(CONFIG_AIROHA_CPU_PM_DOMAIN)     += airoha-cpu-pmdomain.o
diff --git a/drivers/pmdomain/mediatek/mtk-mfg-pmdomain.c 
b/drivers/pmdomain/mediatek/mtk-mfg-pmdomain.c
new file mode 100644
index 
0000000000000000000000000000000000000000..3137c270603fad9cca964582a6f700ddf9ac2c18
--- /dev/null
+++ b/drivers/pmdomain/mediatek/mtk-mfg-pmdomain.c
@@ -0,0 +1,1027 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for MediaTek MFlexGraphics Devices
+ *
+ * Copyright (C) 2025, Collabora Ltd.
+ */
+
+#include <linux/completion.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/container_of.h>
+#include <linux/iopoll.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/overflow.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_opp.h>
+#include <linux/regulator/consumer.h>
+#include <linux/units.h>
+
+#define GPR_LP_STATE           0x0028
+#define   EB_ON_SUSPEND                0x0
+#define   EB_ON_RESUME         0x1
+#define GPR_IPI_MAGIC          0x34
+
+#define RPC_PWR_CON            0x0504
+#define   PWR_ACK_M            GENMASK(31, 30)
+#define RPC_DUMMY_REG_2                0x0658
+#define RPC_GHPM_CFG0_CON      0x0800
+#define   GHPM_ENABLE_M                BIT(0)
+#define   GHPM_ON_SEQ_M                BIT(2)
+#define RPC_GHPM_RO0_CON       0x09A4
+#define   GHPM_STATE_M         GENMASK(7, 0)
+#define   GHPM_PWR_STATE_M     BIT(16)
+
+#define GF_REG_MAGIC                   0x0000
+#define GF_REG_GPU_OPP_IDX             0x0004
+#define GF_REG_STK_OPP_IDX             0x0008
+#define GF_REG_GPU_OPP_NUM             0x000c
+#define GF_REG_STK_OPP_NUM             0x0010
+#define GF_REG_GPU_OPP_SNUM            0x0014
+#define GF_REG_STK_OPP_SNUM            0x0018
+#define GF_REG_POWER_COUNT             0x001c
+#define GF_REG_BUCK_COUNT              0x0020
+#define GF_REG_MTCMOS_COUNT            0x0024
+#define GF_REG_CG_COUNT                        0x0028 /* CG = Clock Gate? */
+#define GF_REG_ACTIVE_COUNT            0x002C
+#define GF_REG_TEMP_RAW                        0x0030
+#define GF_REG_TEMP_NORM_GPU           0x0034
+#define GF_REG_TEMP_HIGH_GPU           0x0038
+#define GF_REG_TEMP_NORM_STK           0x003C
+#define GF_REG_TEMP_HIGH_STK           0x0040
+#define GF_REG_FREQ_CUR_GPU            0x0044
+#define GF_REG_FREQ_CUR_STK            0x0048
+#define GF_REG_FREQ_OUT_GPU            0x004C /* Guess: actual achieved freq */
+#define GF_REG_FREQ_OUT_STK            0x0050 /* Guess: actual achieved freq */
+#define GF_REG_FREQ_METER_GPU          0x0054 /* Seems unused, always 0 */
+#define GF_REG_FREQ_METER_STK          0x0058 /* Seems unused, always 0 */
+#define GF_REG_VOLT_CUR_GPU            0x005C /* in tens of microvolts */
+#define GF_REG_VOLT_CUR_STK            0x0060 /* in tens of microvolts */
+#define GF_REG_VOLT_CUR_GPU_SRAM       0x0064
+#define GF_REG_VOLT_CUR_STK_SRAM       0x0068
+#define GF_REG_VOLT_CUR_GPU_REG                0x006C /* Seems unused, always 
0 */
+#define GF_REG_VOLT_CUR_STK_REG                0x0070 /* Seems unused, always 
0 */
+#define GF_REG_VOLT_CUR_GPU_REG_SRAM   0x0074
+#define GF_REG_VOLT_CUR_STK_REG_SRAM   0x0078
+#define GF_REG_PWR_CUR_GPU             0x007C /* in milliwatts */
+#define GF_REG_PWR_CUR_STK             0x0080 /* in milliwatts */
+#define GF_REG_PWR_MAX_GPU             0x0084 /* in milliwatts */
+#define GF_REG_PWR_MAX_STK             0x0088 /* in milliwatts */
+#define GF_REG_PWR_MIN_GPU             0x008C /* in milliwatts */
+#define GF_REG_PWR_MIN_STK             0x0090 /* in milliwatts */
+#define GF_REG_LEAKAGE_RT_GPU          0x0094 /* Unknown */
+#define GF_REG_LEAKAGE_RT_STK          0x0098 /* Unknown */
+#define GF_REG_LEAKAGE_RT_SRAM         0x009C /* Unknown */
+#define GF_REG_LEAKAGE_HT_GPU          0x00A0 /* Unknown */
+#define GF_REG_LEAKAGE_HT_STK          0x00A4 /* Unknown */
+#define GF_REG_LEAKAGE_HT_SRAM         0x00A8 /* Unknown */
+#define GF_REG_VOLT_DAC_LOW_GPU                0x00AC /* Seems unused, always 
0 */
+#define GF_REG_VOLT_DAC_LOW_STK                0x00B0 /* Seems unused, always 
0 */
+#define GF_REG_OPP_CUR_CEIL            0x00B4
+#define GF_REG_OPP_CUR_FLOOR           0x00B8
+#define GF_REG_OPP_CUR_LIMITER_CEIL    0x00BC
+#define GF_REG_OPP_CUR_LIMITER_FLOOR   0x00C0
+#define GF_REG_OPP_PRIORITY_CEIL       0x00C4
+#define GF_REG_OPP_PRIORITY_FLOOR      0x00C8
+#define GF_REG_PWR_CTL                 0x00CC
+#define GF_REG_ACTIVE_SLEEP_CTL                0x00D0
+#define GF_REG_DVFS_STATE              0x00D4
+#define GF_REG_SHADER_PRESENT          0x00D8
+#define GF_REG_ASENSOR_ENABLE          0x00DC
+#define GF_REG_AGING_LOAD              0x00E0
+#define GF_REG_AGING_MARGIN            0x00E4
+#define GF_REG_AVS_ENABLE              0x00E8
+#define GF_REG_AVS_MARGIN              0x00EC
+#define GF_REG_CHIP_TYPE               0x00F0
+#define GF_REG_SB_VERSION              0x00F4
+#define GF_REG_PTP_VERSION             0x00F8
+#define GF_REG_DBG_VERSION             0x00FC
+#define GF_REG_KDBG_VERSION            0x0100
+#define GF_REG_GPM1_MODE               0x0104
+#define GF_REG_GPM3_MODE               0x0108
+#define GF_REG_DFD_MODE                        0x010C
+#define GF_REG_DUAL_BUCK               0x0110
+#define GF_REG_SEGMENT_ID              0x0114
+#define GF_REG_POWER_TIME_H            0x0118
+#define GF_REG_POWER_TIME_L            0x011C
+#define GF_REG_PWR_STATUS              0x0120
+#define GF_REG_STRESS_TEST             0x0124
+#define GF_REG_TEST_MODE               0x0128
+#define GF_REG_IPS_MODE                        0x012C
+#define GF_REG_TEMP_COMP_MODE          0x0130
+#define GF_REG_HT_TEMP_COMP_MODE       0x0134
+#define GF_REG_PWR_TRACKER_MODE                0x0138
+#define GF_REG_OPP_TABLE_GPU           0x0314
+#define GF_REG_OPP_TABLE_STK           0x09A4
+#define GF_REG_OPP_TABLE_GPU_S         0x1034
+#define GF_REG_OPP_TABLE_STK_S         0x16c4
+#define GF_REG_LIMIT_TABLE             0x1d54
+#define GF_REG_GPM3_TABLE              0x223C
+
+#define MFG_MT8196_E2_ID               0x101
+#define GPUEB_SLEEP_MAGIC              0x55667788UL
+#define GPUEB_MEM_MAGIC                        0xBABADADAUL
+
+#define GPUEB_TIMEOUT_US               10000UL
+#define GPUEB_POLL_US                  50
+
+#define MAX_OPP_NUM                    70
+
+#define GPUEB_MBOX_MAX_RX_SIZE         32 /* in bytes */
+
+/*
+ * This enum is part of the ABI of the GPUEB firmware. Don't change the
+ * numbering, as you would wreak havoc.
+ */
+enum mtk_mfg_ipi_cmd {
+       CMD_INIT_SHARED_MEM             = 0,
+       CMD_GET_FREQ_BY_IDX             = 1,
+       CMD_GET_POWER_BY_IDX            = 2,
+       CMD_GET_OPPIDX_BY_FREQ          = 3,
+       CMD_GET_LEAKAGE_POWER           = 4,
+       CMD_SET_LIMIT                   = 5,
+       CMD_POWER_CONTROL               = 6,
+       CMD_ACTIVE_SLEEP_CONTROL        = 7,
+       CMD_COMMIT                      = 8,
+       CMD_DUAL_COMMIT                 = 9,
+       CMD_PDCA_CONFIG                 = 10,
+       CMD_UPDATE_DEBUG_OPP_INFO       = 11,
+       CMD_SWITCH_LIMIT                = 12,
+       CMD_FIX_TARGET_OPPIDX           = 13,
+       CMD_FIX_DUAL_TARGET_OPPIDX      = 14,
+       CMD_FIX_CUSTOM_FREQ_VOLT        = 15,
+       CMD_FIX_DUAL_CUSTOM_FREQ_VOLT   = 16,
+       CMD_SET_MFGSYS_CONFIG           = 17,
+       CMD_MSSV_COMMIT                 = 18,
+       CMD_NUM                         = 19,
+};
+
+/*
+ * This struct is part of the ABI of the GPUEB firmware. Changing it, or
+ * reordering fields in it, will break things, so don't do it. Thank you.
+ */
+struct __packed mtk_mfg_ipi_msg {
+       __le32 magic;
+       __le32 cmd;
+       __le32 target;
+       /*
+        * Downstream relies on the compiler to implicitly add the following
+        * padding, as it declares the struct as non-packed.
+        */
+       __le32 reserved;
+       union {
+               s32 __bitwise oppidx;
+               s32 __bitwise return_value;
+               __le32 freq;
+               __le32 volt;
+               __le32 power;
+               __le32 power_state;
+               __le32 mode;
+               __le32 value;
+               struct {
+                       __le64 base;
+                       __le32 size;
+               } shared_mem;
+               struct {
+                       __le32 freq;
+                       __le32 volt;
+               } custom;
+               struct {
+                       __le32 limiter;
+                       s32 __bitwise ceiling_info;
+                       s32 __bitwise floor_info;
+               } set_limit;
+               struct {
+                       __le32 target;
+                       __le32 val;
+               } mfg_cfg;
+               struct {
+                       __le32 target;
+                       __le32 val;
+               } mssv;
+               struct {
+                       s32 __bitwise gpu_oppidx;
+                       s32 __bitwise stack_oppidx;
+               } dual_commit;
+               struct {
+                       __le32 fgpu;
+                       __le32 vgpu;
+                       __le32 fstack;
+                       __le32 vstack;
+               } dual_custom;
+       } u;
+};
+
+struct __packed mtk_mfg_ipi_sleep_msg {
+       __le32 event;
+       __le32 state;
+       __le32 magic;
+};
+
+/**
+ * struct mtk_mfg_opp_entry - OPP table entry from firmware
+ * @freq_khz: The operating point's frequency in kilohertz
+ * @voltage_core: The operating point's core voltage in tens of microvolts
+ * @voltage_sram: The operating point's SRAM voltage in tens of microvolts
+ * @posdiv: exponent of base 2 for PLL frequency divisor used for this OPP
+ * @voltage_margin: Number of tens of microvolts the voltage can be undershot
+ * @power_mw: estimate of power usage at this operating point, in milliwatts
+ *
+ * This struct is part of the ABI with the EB firmware. Do not change it.
+ */
+struct __packed mtk_mfg_opp_entry {
+       __le32 freq_khz;
+       __le32 voltage_core;
+       __le32 voltage_sram;
+       __le32 posdiv;
+       __le32 voltage_margin;
+       __le32 power_mw;
+};
+
+struct mtk_mfg_mbox {
+       struct mbox_client cl;
+       struct completion rx_done;
+       struct mtk_mfg *mfg;
+       struct mbox_chan *ch;
+       void *rx_data;
+};
+
+struct mtk_mfg {
+       struct generic_pm_domain pd;
+       struct platform_device *pdev;
+       struct clk *clk_eb;
+       struct clk_bulk_data *gpu_clks;
+       struct clk_hw clk_core_hw;
+       struct clk_hw clk_stack_hw;
+       struct regulator_bulk_data *gpu_regs;
+       void __iomem *rpc;
+       void __iomem *gpr;
+       void __iomem *shared_mem;
+       phys_addr_t shared_mem_phys;
+       unsigned int shared_mem_size;
+       u16 ghpm_en_reg;
+       u32 ipi_magic;
+       unsigned short num_gpu_opps;
+       unsigned short num_stack_opps;
+       struct dev_pm_opp_data *gpu_opps;
+       struct dev_pm_opp_data *stack_opps;
+       struct mtk_mfg_mbox *gf_mbox;
+       struct mtk_mfg_mbox *slp_mbox;
+       const struct mtk_mfg_variant *variant;
+};
+
+struct mtk_mfg_variant {
+       const char *const *clk_names;
+       unsigned int num_clks;
+       const char *const *regulator_names;
+       unsigned int num_regulators;
+       /** @turbo_below: opp indices below this value are considered turbo */
+       unsigned int turbo_below;
+       int (*init)(struct mtk_mfg *mfg);
+};
+
+static inline struct mtk_mfg *mtk_mfg_from_genpd(struct generic_pm_domain *pd)
+{
+       return container_of(pd, struct mtk_mfg, pd);
+}
+
+static inline void mtk_mfg_update_reg_bits(void __iomem *addr, u32 mask, u32 
val)
+{
+       writel((readl(addr) & ~mask) | (val & mask), addr);
+}
+
+static inline bool mtk_mfg_is_powered_on(struct mtk_mfg *mfg)
+{
+       return (readl(mfg->rpc + RPC_PWR_CON) & PWR_ACK_M) == PWR_ACK_M;
+}
+
+static unsigned long mtk_mfg_recalc_rate_gpu(struct clk_hw *hw,
+                                            unsigned long parent_rate)
+{
+       struct mtk_mfg *mfg = container_of(hw, struct mtk_mfg, clk_core_hw);
+
+       return readl(mfg->shared_mem + GF_REG_FREQ_OUT_GPU) * HZ_PER_KHZ;
+}
+
+static long mtk_mfg_round_rate(struct clk_hw *hw, unsigned long rate,
+                              unsigned long *parent_rate)
+{
+       /*
+        * The round_rate callback needs to be implemented to avoid returning
+        * the current clock frequency, rather than something even remotely
+        * close to the frequency that was asked for.
+        *
+        * Instead of writing considerable amounts of possibly slow code just to
+        * somehow figure out which of the three PLLs to round for, or even to
+        * do a search through one of two OPP tables in order to find the 
closest
+        * OPP of a frequency, just return the rate as-is. This avoids devfreq
+        * "rounding" a request for the lowest frequency to the possibly very
+        * high current frequency, breaking the powersave governor in the 
process.
+        */
+
+       return rate;
+}
+
+static unsigned long mtk_mfg_recalc_rate_stack(struct clk_hw *hw,
+                                              unsigned long parent_rate)
+{
+       struct mtk_mfg *mfg = container_of(hw, struct mtk_mfg, clk_stack_hw);
+
+       return readl(mfg->shared_mem + GF_REG_FREQ_OUT_STK) * HZ_PER_KHZ;
+}
+
+static const struct clk_ops mtk_mfg_clk_gpu_ops = {
+       .recalc_rate = mtk_mfg_recalc_rate_gpu,
+       .round_rate = mtk_mfg_round_rate,
+};
+
+static const struct clk_ops mtk_mfg_clk_stack_ops = {
+       .recalc_rate = mtk_mfg_recalc_rate_stack,
+       .round_rate = mtk_mfg_round_rate,
+};
+
+static const struct clk_init_data mtk_mfg_clk_gpu_init = {
+       .name = "gpu-core",
+       .ops = &mtk_mfg_clk_gpu_ops,
+       .flags = CLK_GET_RATE_NOCACHE,
+};
+
+static const struct clk_init_data mtk_mfg_clk_stack_init = {
+       .name = "gpu-stack",
+       .ops = &mtk_mfg_clk_stack_ops,
+       .flags = CLK_GET_RATE_NOCACHE,
+};
+
+static int mtk_mfg_eb_on(struct mtk_mfg *mfg)
+{
+       struct device *dev = &mfg->pdev->dev;
+       u32 val;
+       int ret;
+
+       /*
+        * If MFG is already on from e.g. the bootloader, skip doing the
+        * power-on sequence, as it wouldn't work without powering it off first.
+        */
+       if (mtk_mfg_is_powered_on(mfg))
+               return 0;
+
+       ret = readl_poll_timeout(mfg->rpc + RPC_GHPM_RO0_CON, val,
+                                !(val & (GHPM_PWR_STATE_M | GHPM_STATE_M)),
+                                GPUEB_POLL_US, GPUEB_TIMEOUT_US);
+       if (ret) {
+               dev_err(dev, "timed out waiting for EB to power on\n");
+               return ret;
+       }
+
+       mtk_mfg_update_reg_bits(mfg->rpc + mfg->ghpm_en_reg, GHPM_ENABLE_M,
+                               GHPM_ENABLE_M);
+
+       mtk_mfg_update_reg_bits(mfg->rpc + RPC_GHPM_CFG0_CON, GHPM_ON_SEQ_M, 0);
+       mtk_mfg_update_reg_bits(mfg->rpc + RPC_GHPM_CFG0_CON, GHPM_ON_SEQ_M,
+                               GHPM_ON_SEQ_M);
+
+       mtk_mfg_update_reg_bits(mfg->rpc + mfg->ghpm_en_reg, GHPM_ENABLE_M, 0);
+
+
+       ret = readl_poll_timeout(mfg->rpc + RPC_PWR_CON, val,
+                                (val & PWR_ACK_M) == PWR_ACK_M,
+                                GPUEB_POLL_US, GPUEB_TIMEOUT_US);
+       if (ret) {
+               dev_err(dev, "timed out waiting for EB power ack, val = 0x%X\n",
+                       val);
+               return ret;
+       }
+
+       ret = readl_poll_timeout(mfg->gpr + GPR_LP_STATE, val,
+                                (val == EB_ON_RESUME),
+                                GPUEB_POLL_US, GPUEB_TIMEOUT_US);
+       if (ret) {
+               dev_err(dev, "timed out waiting for EB to resume, status = 
0x%X\n", val);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int mtk_mfg_eb_off(struct mtk_mfg *mfg)
+{
+       struct device *dev = &mfg->pdev->dev;
+       struct mtk_mfg_ipi_sleep_msg msg = {
+               .event = 0,
+               .state = 0,
+               .magic = GPUEB_SLEEP_MAGIC
+       };
+       u32 val;
+       int ret;
+
+       ret = mbox_send_message(mfg->slp_mbox->ch, &msg);
+       if (ret < 0) {
+               dev_err(dev, "Cannot send sleep command: %pe\n", ERR_PTR(ret));
+               return ret;
+       }
+
+       ret = readl_poll_timeout(mfg->rpc + RPC_PWR_CON, val,
+                                !(val & PWR_ACK_M), GPUEB_POLL_US,
+                                GPUEB_TIMEOUT_US);
+
+       if (ret) {
+               dev_err(dev, "Timed out waiting for EB to power off, 
val=0x%08X\n", val);
+               return ret;
+       }
+
+       return 0;
+}
+
+/**
+ * mtk_mfg_send_ipi - synchronously send an IPI message on the gpufreq channel
+ * @mfg: pointer to this driver instance's private &struct mtk_mfg
+ * @msg: pointer to a message to send; will have magic filled and response 
assigned
+ *
+ * Send an IPI message on the gpufreq channel, and wait for a response. Once a
+ * response is received, assign a pointer to the response buffer (valid until
+ * next response is received) to @msg.
+ *
+ * Returns 0 on success, negative errno on failure.
+ */
+static int mtk_mfg_send_ipi(struct mtk_mfg *mfg, struct mtk_mfg_ipi_msg *msg)
+{
+       struct device *dev = &mfg->pdev->dev;
+       unsigned long wait;
+       int ret;
+
+       msg->magic = mfg->ipi_magic;
+
+       ret = mbox_send_message(mfg->gf_mbox->ch, msg);
+       if (ret < 0) {
+               dev_err(dev, "Cannot send GPUFreq IPI command: %pe\n", 
ERR_PTR(ret));
+               return ret;
+       }
+
+       wait = wait_for_completion_timeout(&mfg->gf_mbox->rx_done, 
msecs_to_jiffies(500));
+       if (!wait)
+               return -ETIMEDOUT;
+
+       msg = mfg->gf_mbox->rx_data;
+
+       if (msg->u.return_value < 0) {
+               dev_err(dev, "IPI return: %d\n", msg->u.return_value);
+               return -EPROTO;
+       }
+
+       return 0;
+}
+
+static int mtk_mfg_init_shared_mem(struct mtk_mfg *mfg)
+{
+       struct device *dev = &mfg->pdev->dev;
+       struct mtk_mfg_ipi_msg msg = {};
+       int ret;
+
+       dev_dbg(dev, "clearing GPUEB shared memory, 0x%X bytes\n", 
mfg->shared_mem_size);
+       memset_io(mfg->shared_mem, 0, mfg->shared_mem_size);
+
+       msg.cmd = CMD_INIT_SHARED_MEM;
+       msg.u.shared_mem.base = mfg->shared_mem_phys;
+       msg.u.shared_mem.size = mfg->shared_mem_size;
+
+       ret = mtk_mfg_send_ipi(mfg, &msg);
+       if (ret)
+               return ret;
+
+       if (readl(mfg->shared_mem) != GPUEB_MEM_MAGIC) {
+               dev_err(dev, "EB did not initialise shared memory correctly\n");
+               return -EIO;
+       }
+
+       return 0;
+}
+
+static int mtk_mfg_power_control(struct mtk_mfg *mfg, bool enabled)
+{
+       struct mtk_mfg_ipi_msg msg = {};
+
+       msg.cmd = CMD_POWER_CONTROL;
+       msg.u.power_state = enabled ? 1 : 0;
+
+       return mtk_mfg_send_ipi(mfg, &msg);
+}
+
+static int mtk_mfg_set_oppidx(struct mtk_mfg *mfg, unsigned int opp_idx)
+{
+       struct mtk_mfg_ipi_msg msg = {};
+       int ret;
+
+       if (opp_idx >= mfg->num_gpu_opps)
+               return -EINVAL;
+
+       msg.cmd = CMD_FIX_DUAL_TARGET_OPPIDX;
+       msg.u.dual_commit.gpu_oppidx = opp_idx;
+       msg.u.dual_commit.stack_oppidx = opp_idx;
+
+       ret = mtk_mfg_send_ipi(mfg, &msg);
+       if (ret) {
+               dev_err(&mfg->pdev->dev, "Failed to set OPP %u: %pe\n",
+                       opp_idx, ERR_PTR(ret));
+               return ret;
+       }
+
+       return 0;
+}
+
+static int mtk_mfg_read_opp_tables(struct mtk_mfg *mfg)
+{
+       struct device *dev = &mfg->pdev->dev;
+       struct mtk_mfg_opp_entry e = {};
+       unsigned int i;
+
+       mfg->num_gpu_opps = readl(mfg->shared_mem + GF_REG_GPU_OPP_NUM);
+       mfg->num_stack_opps = readl(mfg->shared_mem + GF_REG_STK_OPP_NUM);
+
+       if (mfg->num_gpu_opps > MAX_OPP_NUM || mfg->num_gpu_opps == 0) {
+               dev_err(dev, "GPU OPP count (%u) out of range %u >= count > 
0\n",
+                       mfg->num_gpu_opps, MAX_OPP_NUM);
+               return -EINVAL;
+       }
+
+       if (mfg->num_stack_opps && mfg->num_stack_opps > MAX_OPP_NUM) {
+               dev_err(dev, "Stack OPP count (%u) out of range %u >= count >= 
0\n",
+                       mfg->num_stack_opps, MAX_OPP_NUM);
+               return -EINVAL;
+       }
+
+       mfg->gpu_opps = devm_kcalloc(dev, mfg->num_gpu_opps,
+                                    sizeof(struct dev_pm_opp_data), 
GFP_KERNEL);
+       if (!mfg->gpu_opps)
+               return -ENOMEM;
+
+       if (mfg->num_stack_opps) {
+               mfg->stack_opps = devm_kcalloc(dev, mfg->num_stack_opps,
+                                              sizeof(struct dev_pm_opp_data), 
GFP_KERNEL);
+               if (!mfg->stack_opps)
+                       return -ENOMEM;
+       }
+
+       for (i = 0; i < mfg->num_gpu_opps; i++) {
+               memcpy_fromio(&e, mfg->shared_mem + GF_REG_OPP_TABLE_GPU + i * 
sizeof(e),
+                             sizeof(e));
+               if (mem_is_zero(&e, sizeof(e))) {
+                       dev_err(dev, "ran into an empty GPU OPP at index %u\n",
+                               i);
+                       return -EINVAL;
+               }
+               mfg->gpu_opps[i].freq = e.freq_khz * HZ_PER_KHZ;
+               mfg->gpu_opps[i].u_volt = e.voltage_core * 10;
+               mfg->gpu_opps[i].level = i;
+               if (i < mfg->variant->turbo_below)
+                       mfg->gpu_opps[i].turbo = true;
+       }
+
+       for (i = 0; i < mfg->num_stack_opps; i++) {
+               memcpy_fromio(&e, mfg->shared_mem + GF_REG_OPP_TABLE_STK + i * 
sizeof(e),
+                             sizeof(e));
+               if (mem_is_zero(&e, sizeof(e))) {
+                       dev_err(dev, "ran into an empty Stack OPP at index 
%u\n",
+                               i);
+                       return -EINVAL;
+               }
+               mfg->stack_opps[i].freq = e.freq_khz * HZ_PER_KHZ;
+               mfg->stack_opps[i].u_volt = e.voltage_core * 10;
+               mfg->stack_opps[i].level = i;
+               if (i < mfg->variant->turbo_below)
+                       mfg->stack_opps[i].turbo = true;
+       }
+
+       return 0;
+}
+
+static const char *const mtk_mfg_mt8196_clk_names[] = {
+       "core",
+       "stack0",
+       "stack1",
+};
+
+static const char *const mtk_mfg_mt8196_regulators[] = {
+       "core",
+       "stack",
+       "sram",
+};
+
+static int mtk_mfg_mt8196_init(struct mtk_mfg *mfg)
+{
+       void __iomem *e2_base;
+
+       e2_base = devm_platform_ioremap_resource_byname(mfg->pdev, 
"hw-revision");
+       if (IS_ERR(e2_base))
+               return dev_err_probe(&mfg->pdev->dev, PTR_ERR(e2_base),
+                                    "Couldn't get hw-revision register\n");
+
+       if (readl(e2_base) == MFG_MT8196_E2_ID)
+               mfg->ghpm_en_reg = RPC_DUMMY_REG_2;
+       else
+               mfg->ghpm_en_reg = RPC_GHPM_CFG0_CON;
+
+       return 0;
+};
+
+static const struct mtk_mfg_variant mtk_mfg_mt8196_variant = {
+       .clk_names = mtk_mfg_mt8196_clk_names,
+       .num_clks = ARRAY_SIZE(mtk_mfg_mt8196_clk_names),
+       .regulator_names = mtk_mfg_mt8196_regulators,
+       .num_regulators = ARRAY_SIZE(mtk_mfg_mt8196_regulators),
+       .turbo_below = 7,
+       .init = mtk_mfg_mt8196_init,
+};
+
+static void mtk_mfg_mbox_rx_callback(struct mbox_client *cl, void *mssg)
+{
+       struct mtk_mfg_mbox *mb = container_of(cl, struct mtk_mfg_mbox, cl);
+
+       if (mb->rx_data)
+               mb->rx_data = memcpy(mb->rx_data, mssg, GPUEB_MBOX_MAX_RX_SIZE);
+       complete(&mb->rx_done);
+}
+
+static int mtk_mfg_attach_dev(struct generic_pm_domain *pd, struct device *dev)
+{
+       struct mtk_mfg *mfg = mtk_mfg_from_genpd(pd);
+       struct dev_pm_opp_data *so = mfg->stack_opps;
+       struct dev_pm_opp_data *go = mfg->gpu_opps;
+       struct dev_pm_opp_data *prev_o;
+       struct dev_pm_opp_data *o;
+       int i, ret;
+
+       for (i = mfg->num_gpu_opps - 1; i >= 0; i--) {
+               /*
+                * Adding the lower of the two OPPs avoids gaps of indices in
+                * situations where the GPU OPPs are duplicated a couple of
+                * times when only the Stack OPP is being lowered at that index.
+                */
+               if (i >= mfg->num_stack_opps || go[i].freq < so[i].freq)
+                       o = &go[i];
+               else
+                       o = &so[i];
+
+               /*
+                * Skip indices where both GPU and Stack OPPs are equal. 
Nominally,
+                * OPP core shouldn't care about dupes, but not doing so will 
cause
+                * dev_pm_opp_find_freq_ceil_indexed to -ERANGE later down the 
line.
+                */
+               if (prev_o && prev_o->freq == o->freq)
+                       continue;
+
+               ret = dev_pm_opp_add_dynamic(dev, o);
+               if (ret) {
+                       dev_err(dev, "Failed to add OPP level %u from PD %s: 
%pe\n",
+                               o->level, pd->name, ERR_PTR(ret));
+                       dev_pm_opp_remove_all_dynamic(dev);
+                       return ret;
+               }
+               prev_o = o;
+       }
+
+       return 0;
+}
+
+static void mtk_mfg_detach_dev(struct generic_pm_domain *pd, struct device 
*dev)
+{
+       dev_pm_opp_remove_all_dynamic(dev);
+}
+
+static int mtk_mfg_set_performance(struct generic_pm_domain *pd,
+                                  unsigned int state)
+{
+       struct mtk_mfg *mfg = mtk_mfg_from_genpd(pd);
+
+       /*
+        * pmdomain core intentionally sets a performance state before turning
+        * a domain on, and after turning it off. For the GPUEB however, it's
+        * only possible to act on performance requests when the GPUEB is
+        * powered on. To do this, return cleanly without taking action, and
+        * defer setting what pmdomain core set in mtk_mfg_power_on.
+        */
+       if (mfg->pd.status != GENPD_STATE_ON)
+               return 0;
+
+       return mtk_mfg_set_oppidx(mfg, state);
+}
+
+static int mtk_mfg_power_on(struct generic_pm_domain *pd)
+{
+       struct mtk_mfg *mfg = mtk_mfg_from_genpd(pd);
+       int ret;
+
+       ret = regulator_bulk_enable(mfg->variant->num_regulators,
+                                   mfg->gpu_regs);
+       if (ret)
+               return ret;
+
+       ret = clk_prepare_enable(mfg->clk_eb);
+       if (ret)
+               goto err_disable_regulators;
+
+       ret = clk_bulk_prepare_enable(mfg->variant->num_clks, mfg->gpu_clks);
+       if (ret)
+               goto err_disable_eb_clk;
+
+       ret = mtk_mfg_eb_on(mfg);
+       if (ret)
+               goto err_disable_clks;
+
+       mfg->ipi_magic = readl(mfg->gpr + GPR_IPI_MAGIC);
+
+       ret = mtk_mfg_power_control(mfg, true);
+       if (ret)
+               goto err_eb_off;
+
+       /* Don't try to set a OPP in probe before OPPs have been read from EB */
+       if (mfg->gpu_opps) {
+               /* The aforementioned deferred setting of pmdomain's state */
+               ret = mtk_mfg_set_oppidx(mfg, pd->performance_state);
+               if (ret)
+                       dev_warn(&mfg->pdev->dev, "Failed to set oppidx in 
%s\n", __func__);
+       }
+
+       return 0;
+
+err_eb_off:
+       mtk_mfg_eb_off(mfg);
+err_disable_clks:
+       clk_bulk_disable_unprepare(mfg->variant->num_clks, mfg->gpu_clks);
+err_disable_eb_clk:
+       clk_disable_unprepare(mfg->clk_eb);
+err_disable_regulators:
+       regulator_bulk_disable(mfg->variant->num_regulators, mfg->gpu_regs);
+
+       return ret;
+}
+
+static int mtk_mfg_power_off(struct generic_pm_domain *pd)
+{
+       struct mtk_mfg *mfg = mtk_mfg_from_genpd(pd);
+       struct device *dev = &mfg->pdev->dev;
+       int ret;
+
+       ret = mtk_mfg_power_control(mfg, false);
+       if (ret) {
+               dev_err(dev, "power_control failed: %pe\n", ERR_PTR(ret));
+               return ret;
+       }
+
+       ret = mtk_mfg_eb_off(mfg);
+       if (ret) {
+               dev_err(dev, "eb_off failed: %pe\n", ERR_PTR(ret));
+               return ret;
+       }
+
+       clk_bulk_disable_unprepare(mfg->variant->num_clks, mfg->gpu_clks);
+       clk_disable_unprepare(mfg->clk_eb);
+       ret = regulator_bulk_disable(mfg->variant->num_regulators, 
mfg->gpu_regs);
+       if (ret) {
+               dev_err(dev, "Disabling regulators failed: %pe\n", 
ERR_PTR(ret));
+               return ret;
+       }
+
+       return 0;
+}
+
+static int mtk_mfg_init_mbox(struct mtk_mfg *mfg)
+{
+       struct device *dev = &mfg->pdev->dev;
+       struct mtk_mfg_mbox *gf;
+       struct mtk_mfg_mbox *slp;
+
+       gf = devm_kzalloc(dev, sizeof(*gf), GFP_KERNEL);
+       if (!gf)
+               return -ENOMEM;
+
+       gf->rx_data = devm_kzalloc(dev, GPUEB_MBOX_MAX_RX_SIZE, GFP_KERNEL);
+       if (!gf->rx_data)
+               return -ENOMEM;
+
+       gf->mfg = mfg;
+       init_completion(&gf->rx_done);
+       gf->cl.dev = dev;
+       gf->cl.rx_callback = mtk_mfg_mbox_rx_callback;
+       gf->cl.tx_tout = GPUEB_TIMEOUT_US / USEC_PER_MSEC;
+       gf->ch = mbox_request_channel_byname(&gf->cl, "gpufreq");
+       if (IS_ERR(gf->ch))
+               return PTR_ERR(gf->ch);
+
+       mfg->gf_mbox = gf;
+
+       slp = devm_kzalloc(dev, sizeof(*slp), GFP_KERNEL);
+       if (!slp)
+               return -ENOMEM;
+
+       slp->mfg = mfg;
+       init_completion(&slp->rx_done);
+       slp->cl.dev = dev;
+       slp->cl.tx_tout = GPUEB_TIMEOUT_US / USEC_PER_MSEC;
+       slp->cl.tx_block = true;
+       slp->ch = mbox_request_channel_byname(&slp->cl, "sleep");
+       if (IS_ERR(slp->ch))
+               return PTR_ERR(slp->ch);
+
+       mfg->slp_mbox = slp;
+
+       return 0;
+}
+
+static int mtk_mfg_init_clk_provider(struct mtk_mfg *mfg)
+{
+       struct device *dev = &mfg->pdev->dev;
+       struct clk_hw_onecell_data *clk_data;
+       int ret;
+
+       clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, 2), GFP_KERNEL);
+       if (!clk_data)
+               return -ENOMEM;
+
+       clk_data->num = 2;
+
+       mfg->clk_core_hw.init = &mtk_mfg_clk_gpu_init;
+       mfg->clk_stack_hw.init = &mtk_mfg_clk_stack_init;
+
+       ret = devm_clk_hw_register(dev, &mfg->clk_core_hw);
+       if (ret)
+               return dev_err_probe(dev, ret, "Couldn't register GPU core 
clock\n");
+
+       ret = devm_clk_hw_register(dev, &mfg->clk_stack_hw);
+       if (ret)
+               return dev_err_probe(dev, ret, "Couldn't register GPU stack 
clock\n");
+
+       clk_data->hws[0] = &mfg->clk_core_hw;
+       clk_data->hws[1] = &mfg->clk_stack_hw;
+
+       ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, clk_data);
+       if (ret)
+               return dev_err_probe(dev, ret, "Couldn't register clock 
provider\n");
+
+       return 0;
+}
+
+static int mtk_mfg_probe(struct platform_device *pdev)
+{
+       struct device_node *shmem __free(device_node);
+       struct mtk_mfg *mfg;
+       struct device *dev = &pdev->dev;
+       const struct mtk_mfg_variant *data = of_device_get_match_data(dev);
+       struct resource res;
+       int ret, i;
+
+       mfg = devm_kzalloc(dev, sizeof(*mfg), GFP_KERNEL);
+       if (!mfg)
+               return -ENOMEM;
+
+       mfg->pdev = pdev;
+       mfg->variant = data;
+
+       dev_set_drvdata(dev, mfg);
+
+       mfg->gpr = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(mfg->gpr))
+               return dev_err_probe(dev, PTR_ERR(mfg->gpr),
+                                    "Couldn't retrieve GPR MMIO registers\n");
+
+       mfg->rpc = devm_platform_ioremap_resource(pdev, 1);
+       if (IS_ERR(mfg->rpc))
+               return dev_err_probe(dev, PTR_ERR(mfg->rpc),
+                                    "Couldn't retrieve RPC MMIO registers\n");
+
+       mfg->clk_eb = devm_clk_get(dev, "eb");
+       if (IS_ERR(mfg->clk_eb))
+               return dev_err_probe(dev, PTR_ERR(mfg->clk_eb),
+                                    "Couldn't get 'eb' clock\n");
+
+       mfg->gpu_clks = devm_kcalloc(dev, data->num_clks, 
sizeof(*mfg->gpu_clks),
+                                    GFP_KERNEL);
+       if (!mfg->gpu_clks)
+               return -ENOMEM;
+
+       for (i = 0; i < data->num_clks; i++)
+               mfg->gpu_clks[i].id = data->clk_names[i];
+
+       ret = devm_clk_bulk_get(dev, data->num_clks, mfg->gpu_clks);
+       if (ret)
+               return dev_err_probe(dev, ret, "Couldn't get GPU clocks\n");
+
+       mfg->gpu_regs = devm_kcalloc(dev, data->num_regulators,
+                                    sizeof(*mfg->gpu_regs), GFP_KERNEL);
+       if (!mfg->gpu_regs)
+               return -ENOMEM;
+
+       for (i = 0; i < data->num_regulators; i++)
+               mfg->gpu_regs[i].supply = data->regulator_names[i];
+
+       ret = devm_regulator_bulk_get(dev, data->num_regulators, mfg->gpu_regs);
+       if (ret)
+               return dev_err_probe(dev, ret, "Couldn't get GPU regulators\n");
+
+       ret = of_reserved_mem_region_to_resource(dev->of_node, 0, &res);
+       if (ret)
+               return dev_err_probe(dev, ret, "Couldn't get GPUEB shared 
memory\n");
+
+       mfg->shared_mem = devm_ioremap(dev, res.start, resource_size(&res));
+       if (!mfg->shared_mem)
+               return dev_err_probe(dev, -ENOMEM, "Can't ioremap GPUEB shared 
memory\n");
+       mfg->shared_mem_size = resource_size(&res);
+       mfg->shared_mem_phys = res.start;
+
+       if (data->init) {
+               ret = data->init(mfg);
+               if (ret)
+                       return dev_err_probe(dev, ret, "Variant init failed\n");
+       }
+
+       mfg->pd.name = dev_name(dev);
+       mfg->pd.attach_dev = mtk_mfg_attach_dev;
+       mfg->pd.detach_dev = mtk_mfg_detach_dev;
+       mfg->pd.power_off = mtk_mfg_power_off;
+       mfg->pd.power_on = mtk_mfg_power_on;
+       mfg->pd.set_performance_state = mtk_mfg_set_performance;
+       mfg->pd.flags = GENPD_FLAG_OPP_TABLE_FW;
+
+       ret = pm_genpd_init(&mfg->pd, NULL, false);
+       if (ret)
+               return dev_err_probe(dev, ret, "Failed to initialise power 
domain\n");
+
+       ret = mtk_mfg_init_mbox(mfg);
+       if (ret)
+               return dev_err_probe(dev, ret, "Couldn't initialise mailbox\n");
+
+       ret = mtk_mfg_power_on(&mfg->pd);
+       if (ret)
+               return dev_err_probe(dev, ret, "Failed to power on MFG\n");
+
+       ret = mtk_mfg_init_shared_mem(mfg);
+       if (ret) {
+               dev_err_probe(dev, ret, "Couldn't initialize EB shared 
memory\n");
+               goto out;
+       }
+
+       ret = mtk_mfg_read_opp_tables(mfg);
+       if (ret) {
+               dev_err_probe(dev, ret, "Error reading OPP tables from EB\n");
+               goto out;
+       }
+
+       ret = mtk_mfg_init_clk_provider(mfg);
+       if (ret)
+               goto out;
+
+       ret = of_genpd_add_provider_simple(dev->of_node, &mfg->pd);
+       if (ret) {
+               dev_err_probe(dev, ret, "Failed to add pmdomain provider\n");
+               goto out;
+       }
+
+       return 0;
+
+out:
+       mtk_mfg_power_off(&mfg->pd);
+       return ret;
+}
+
+static const struct of_device_id mtk_mfg_of_match[] = {
+       { .compatible = "mediatek,mt8196-gpufreq", .data = 
&mtk_mfg_mt8196_variant },
+       {}
+};
+MODULE_DEVICE_TABLE(of, mtk_mfg_of_match);
+
+static void mtk_mfg_remove(struct platform_device *pdev)
+{
+       struct mtk_mfg *mfg = dev_get_drvdata(&pdev->dev);
+
+       if (mtk_mfg_is_powered_on(mfg))
+               mtk_mfg_power_off(&mfg->pd);
+
+       of_genpd_del_provider(pdev->dev.of_node);
+       pm_genpd_remove(&mfg->pd);
+
+       mbox_free_channel(mfg->gf_mbox->ch);
+       mfg->gf_mbox->ch = NULL;
+
+       mbox_free_channel(mfg->slp_mbox->ch);
+       mfg->slp_mbox->ch = NULL;
+}
+
+static struct platform_driver mtk_mfg_driver = {
+       .driver = {
+               .name = "mtk-mfg-pmdomain",
+               .of_match_table = mtk_mfg_of_match,
+               .suppress_bind_attrs = true,
+       },
+       .probe = mtk_mfg_probe,
+       .remove = mtk_mfg_remove,
+};
+module_platform_driver(mtk_mfg_driver);
+
+MODULE_AUTHOR("Nicolas Frattaroli <[email protected]>");
+MODULE_DESCRIPTION("MediaTek MFlexGraphics Power Domain Driver");
+MODULE_LICENSE("GPL");

-- 
2.51.0



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