misc: k3_avs: add driver for K3 Adaptive Voltage Scaling Class 0
authorTero Kristo <t-kristo@ti.com>
Thu, 24 Oct 2019 09:30:46 +0000 (15:00 +0530)
committerTom Rini <trini@konsulko.com>
Thu, 7 Nov 2019 23:39:16 +0000 (18:39 -0500)
Adaptive Voltage Scaling is a technology used in TI SoCs to optimize
the operating voltage based on characterization data written to efuse
during production. Add a driver to support this feature for K3 line of
SoCs, initially for AM65x.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
drivers/misc/Kconfig
drivers/misc/Makefile
drivers/misc/k3_avs.c [new file with mode: 0644]
include/k3-avs.h [new file with mode: 0644]

index 4985ea033b1514c13278a1c27def09661d39aa2e..7a8ba587da5bf1441d0dbbb4be6e13209c6f7f2b 100644 (file)
@@ -421,4 +421,13 @@ config MICROCHIP_FLEXCOM
          Only one function can be used at a time and is chosen at boot time
          according to the device tree.
 
+config K3_AVS0
+       depends on ARCH_K3 && SPL_DM_REGULATOR
+       bool "AVS class 0 support for K3 devices"
+       help
+         K3 devices have the optimized voltage values for the main voltage
+         domains stored in efuse within the VTM IP. This driver reads the
+         optimized voltage from the efuse, so that it can be programmed
+         to the PMIC on board.
+
 endmenu
index f61263640b84625cb6aefd7ede6b12f4b3791c45..870655e80228d09cea5433982c2373b4114e50c2 100644 (file)
@@ -66,3 +66,4 @@ obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress_config.o
 obj-$(CONFIG_WINBOND_W83627) += winbond_w83627.o
 obj-$(CONFIG_JZ4780_EFUSE) += jz4780_efuse.o
 obj-$(CONFIG_MICROCHIP_FLEXCOM) += microchip_flexcom.o
+obj-$(CONFIG_K3_AVS0) += k3_avs.o
diff --git a/drivers/misc/k3_avs.c b/drivers/misc/k3_avs.c
new file mode 100644 (file)
index 0000000..dd7fc3d
--- /dev/null
@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Texas Instruments' K3 Clas 0 Adaptive Voltage Scaling driver
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+ *      Tero Kristo <t-kristo@ti.com>
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <i2c.h>
+#include <k3-avs.h>
+#include <power/regulator.h>
+
+#define AM6_VTM_DEVINFO(i)     (priv->base + 0x100 + 0x20 * (i))
+#define AM6_VTM_OPPVID_VD(i)   (priv->base + 0x104 + 0x20 * (i))
+
+#define AM6_VTM_AVS0_SUPPORTED BIT(12)
+
+#define AM6_VTM_OPP_SHIFT(opp) (8 * (opp))
+#define AM6_VTM_OPP_MASK       0xff
+
+#define VD_FLAG_INIT_DONE      BIT(0)
+
+struct k3_avs_privdata {
+       void *base;
+       struct vd_config *vd_config;
+};
+
+struct opp {
+       u32 freq;
+       u32 volt;
+};
+
+struct vd_data {
+       int id;
+       u8 opp;
+       u8 flags;
+       int dev_id;
+       int clk_id;
+       struct opp opps[NUM_OPPS];
+       struct udevice *supply;
+};
+
+struct vd_config {
+       struct vd_data *vds;
+       u32 (*efuse_xlate)(struct k3_avs_privdata *priv, int idx, int opp);
+};
+
+static struct k3_avs_privdata *k3_avs_priv;
+
+/**
+ * am6_efuse_voltage: read efuse voltage from VTM
+ * @priv: driver private data
+ * @idx: VD to read efuse for
+ * @opp: opp id to read
+ *
+ * Reads efuse value for the specified OPP, and converts the register
+ * value to a voltage. Returns the voltage in uV, or 0 if nominal voltage
+ * should be used.
+ *
+ * Efuse val to volt conversion logic:
+ *
+ * val > 171 volt increments in 20mV steps with base 171 => 1.66V
+ * val between 115 to 11 increments in 10mV steps with base 115 => 1.1V
+ * val between 15 to 115 increments in 5mV steps with base 15 => .6V
+ * val between 1 to 15 increments in 20mv steps with base 0 => .3V
+ * val 0 is invalid
+ */
+static u32 am6_efuse_xlate(struct k3_avs_privdata *priv, int idx, int opp)
+{
+       u32 val = readl(AM6_VTM_OPPVID_VD(idx));
+
+       val >>= AM6_VTM_OPP_SHIFT(opp);
+       val &= AM6_VTM_OPP_MASK;
+
+       if (!val)
+               return 0;
+
+       if (val > 171)
+               return 1660000 + 20000 * (val - 171);
+
+       if (val > 115)
+               return 1100000 + 10000 * (val - 115);
+
+       if (val > 15)
+               return 600000 + 5000 * (val - 15);
+
+       return 300000 + 20000 * val;
+}
+
+static int k3_avs_program_voltage(struct k3_avs_privdata *priv,
+                                 struct vd_data *vd,
+                                 int opp_id)
+{
+       u32 volt = vd->opps[opp_id].volt;
+       struct vd_data *vd2;
+
+       if (!vd->supply)
+               return -ENODEV;
+
+       vd->opp = opp_id;
+       vd->flags |= VD_FLAG_INIT_DONE;
+
+       /* Take care of ganged rails and pick the Max amongst them*/
+       for (vd2 = priv->vd_config->vds; vd2->id >= 0; vd2++) {
+               if (vd == vd2)
+                       continue;
+
+               if (vd2->supply != vd->supply)
+                       continue;
+
+               if (vd2->opps[vd2->opp].volt > volt)
+                       volt = vd2->opps[vd2->opp].volt;
+
+               vd2->flags |= VD_FLAG_INIT_DONE;
+       }
+
+       return regulator_set_value(vd->supply, volt);
+}
+
+static struct vd_data *get_vd(struct k3_avs_privdata *priv, int idx)
+{
+       struct vd_data *vd;
+
+       for (vd = priv->vd_config->vds; vd->id >= 0 && vd->id != idx; vd++)
+               ;
+
+       if (vd->id < 0)
+               return NULL;
+
+       return vd;
+}
+
+/**
+ * k3_avs_set_opp: Sets the voltage for an arbitrary VD rail
+ * @dev: AVS device
+ * @vdd_id: voltage domain ID
+ * @opp_id: OPP ID
+ *
+ * Programs the desired OPP value for the defined voltage rail. This
+ * should be called from board files if reconfiguration is desired.
+ * Returns 0 on success, negative error value on failure.
+ */
+int k3_avs_set_opp(struct udevice *dev, int vdd_id, int opp_id)
+{
+       struct k3_avs_privdata *priv = dev_get_priv(dev);
+       struct vd_data *vd;
+
+       vd = get_vd(priv, vdd_id);
+       if (!vd)
+               return -EINVAL;
+
+       return k3_avs_program_voltage(priv, vd, opp_id);
+}
+
+static int match_opp(struct vd_data *vd, u32 freq)
+{
+       struct opp *opp;
+       int opp_id;
+
+       for (opp_id = 0; opp_id < NUM_OPPS; opp_id++) {
+               opp = &vd->opps[opp_id];
+               if (opp->freq == freq)
+                       return opp_id;
+       }
+
+       printf("No matching OPP found for freq %d.\n", freq);
+
+       return -EINVAL;
+}
+
+/**
+ * k3_avs_notify_freq: Notify clock rate change towards AVS subsystem
+ * @dev_id: Device ID for the clock to be changed
+ * @clk_id: Clock ID for the clock to be changed
+ * @freq: New frequency for clock
+ *
+ * Checks if the provided clock is the MPU clock or not, if not, return
+ * immediately. If MPU clock is provided, maps the provided MPU frequency
+ * towards an MPU OPP, and programs the voltage to the regulator. Return 0
+ * on success, negative error value on failure.
+ */
+int k3_avs_notify_freq(int dev_id, int clk_id, u32 freq)
+{
+       int opp_id;
+       struct k3_avs_privdata *priv = k3_avs_priv;
+       struct vd_data *vd;
+
+       for (vd = priv->vd_config->vds; vd->id >= 0; vd++) {
+               if (vd->dev_id != dev_id || vd->clk_id != clk_id)
+                       continue;
+
+               opp_id = match_opp(vd, freq);
+               if (opp_id < 0)
+                       return opp_id;
+
+               vd->opp = opp_id;
+               return k3_avs_program_voltage(priv, vd, opp_id);
+       }
+
+       return -EINVAL;
+}
+
+static int k3_avs_configure(struct udevice *dev, struct k3_avs_privdata *priv)
+{
+       struct vd_config *conf;
+       int ret;
+       char pname[20];
+       struct vd_data *vd;
+
+       conf = (void *)dev_get_driver_data(dev);
+
+       priv->vd_config = conf;
+
+       for (vd = conf->vds; vd->id >= 0; vd++) {
+               sprintf(pname, "vdd-supply-%d", vd->id);
+               ret = device_get_supply_regulator(dev, pname, &vd->supply);
+               if (ret)
+                       dev_warn(dev, "supply not found for VD%d.\n", vd->id);
+
+               sprintf(pname, "ti,default-opp-%d", vd->id);
+               ret = dev_read_u32_default(dev, pname, -1);
+               if (ret != -1)
+                       vd->opp = ret;
+       }
+
+       return 0;
+}
+
+/**
+ * k3_avs_probe: parses VD info from VTM, and re-configures the OPP data
+ *
+ * Parses all VDs on a device calculating the AVS class-0 voltages for them,
+ * and updates the vd_data based on this. The vd_data itself shall be used
+ * to program the required OPPs later on. Returns 0 on success, negative
+ * error value on failure.
+ */
+static int k3_avs_probe(struct udevice *dev)
+{
+       int opp_id;
+       u32 volt;
+       struct opp *opp;
+       struct k3_avs_privdata *priv;
+       struct vd_data *vd;
+       int ret;
+
+       priv = dev_get_priv(dev);
+
+       k3_avs_priv = priv;
+
+       ret = k3_avs_configure(dev, priv);
+       if (ret)
+               return ret;
+
+       priv->base = dev_read_addr_ptr(dev);
+       if (!priv->base)
+               return -ENODEV;
+
+       for (vd = priv->vd_config->vds; vd->id >= 0; vd++) {
+               if (!(readl(AM6_VTM_DEVINFO(vd->id)) &
+                     AM6_VTM_AVS0_SUPPORTED)) {
+                       dev_warn(dev, "AVS-class 0 not supported for VD%d\n",
+                                vd->id);
+                       continue;
+               }
+
+               for (opp_id = 0; opp_id < NUM_OPPS; opp_id++) {
+                       opp = &vd->opps[opp_id];
+
+                       if (!opp->freq)
+                               continue;
+
+                       volt = priv->vd_config->efuse_xlate(priv, vd->id,
+                                                           opp_id);
+                       if (volt)
+                               opp->volt = volt;
+               }
+       }
+
+       for (vd = priv->vd_config->vds; vd->id >= 0; vd++) {
+               if (vd->flags & VD_FLAG_INIT_DONE)
+                       continue;
+
+               k3_avs_program_voltage(priv, vd, vd->opp);
+       }
+
+       return 0;
+}
+
+static struct vd_data am654_vd_data[] = {
+       {
+               .id = AM6_VDD_CORE,
+               .dev_id = 82, /* AM6_DEV_CBASS0 */
+               .clk_id = 0, /* main sysclk0 */
+               .opp = AM6_OPP_NOM,
+               .opps = {
+                       [AM6_OPP_NOM] = {
+                               .volt = 1000000,
+                               .freq = 250000000, /* CBASS0 */
+                       },
+               },
+       },
+       {
+               .id = AM6_VDD_MPU0,
+               .dev_id = 202, /* AM6_DEV_COMPUTE_CLUSTER_A53_0 */
+               .clk_id = 0, /* ARM clock */
+               .opp = AM6_OPP_NOM,
+               .opps = {
+                       [AM6_OPP_NOM] = {
+                               .volt = 1000000,
+                               .freq = 800000000,
+                       },
+                       [AM6_OPP_OD] = {
+                               .volt = 1100000,
+                               .freq = 1000000000,
+                       },
+                       [AM6_OPP_TURBO] = {
+                               .volt = 1220000,
+                               .freq = 1100000000,
+                       },
+               },
+       },
+       {
+               .id = AM6_VDD_MPU1,
+               .opp = AM6_OPP_NOM,
+               .dev_id = 204, /* AM6_DEV_COMPUTE_CLUSTER_A53_2 */
+               .clk_id = 0, /* ARM clock */
+               .opps = {
+                       [AM6_OPP_NOM] = {
+                               .volt = 1000000,
+                               .freq = 800000000,
+                       },
+                       [AM6_OPP_OD] = {
+                               .volt = 1100000,
+                               .freq = 1000000000,
+                       },
+                       [AM6_OPP_TURBO] = {
+                               .volt = 1220000,
+                               .freq = 1100000000,
+                       },
+               },
+       },
+       { .id = -1 },
+};
+
+static struct vd_config am654_vd_config = {
+       .efuse_xlate = am6_efuse_xlate,
+       .vds = am654_vd_data,
+};
+
+static const struct udevice_id k3_avs_ids[] = {
+       { .compatible = "ti,am654-avs", .data = (ulong)&am654_vd_config },
+       {}
+};
+
+U_BOOT_DRIVER(k3_avs) = {
+       .name = "k3_avs",
+       .of_match = k3_avs_ids,
+       .id = UCLASS_MISC,
+       .probe = k3_avs_probe,
+       .priv_auto_alloc_size = sizeof(struct k3_avs_privdata),
+};
diff --git a/include/k3-avs.h b/include/k3-avs.h
new file mode 100644 (file)
index 0000000..9867481
--- /dev/null
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Texas Instruments' K3 Adaptive Voltage Scaling driver
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+ *      Tero Kristo <t-kristo@ti.com>
+ *
+ */
+
+#ifndef _K3_AVS0_
+#define _K3_AVS0_
+
+#define AM6_VDD_WKUP           0
+#define AM6_VDD_MCU            1
+#define AM6_VDD_CORE           2
+#define AM6_VDD_MPU0           3
+#define AM6_VDD_MPU1           4
+
+#define NUM_OPPS               4
+
+#define AM6_OPP_NOM            1
+#define AM6_OPP_OD             2
+#define AM6_OPP_TURBO          3
+
+int k3_avs_set_opp(struct udevice *dev, int vdd_id, int opp_id);
+int k3_avs_notify_freq(int dev_id, int clk_id, u32 freq);
+
+#endif