misc: k3_avs: add driver for K3 Adaptive Voltage Scaling Class 0
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>
diff --git a/drivers/misc/k3_avs.c b/drivers/misc/k3_avs.c
new file mode 100644
index 0000000..dd7fc3d
--- /dev/null
+++ b/drivers/misc/k3_avs.c
@@ -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),
+};