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-rw-r--r--drivers/clk/qcom/gdsc.c561
1 files changed, 561 insertions, 0 deletions
diff --git a/drivers/clk/qcom/gdsc.c b/drivers/clk/qcom/gdsc.c
new file mode 100644
index 000000000..0f21a8a76
--- /dev/null
+++ b/drivers/clk/qcom/gdsc.c
@@ -0,0 +1,561 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015, 2017-2018, 2022, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include "gdsc.h"
+
+#define PWR_ON_MASK BIT(31)
+#define EN_REST_WAIT_MASK GENMASK_ULL(23, 20)
+#define EN_FEW_WAIT_MASK GENMASK_ULL(19, 16)
+#define CLK_DIS_WAIT_MASK GENMASK_ULL(15, 12)
+#define SW_OVERRIDE_MASK BIT(2)
+#define HW_CONTROL_MASK BIT(1)
+#define SW_COLLAPSE_MASK BIT(0)
+#define GMEM_CLAMP_IO_MASK BIT(0)
+#define GMEM_RESET_MASK BIT(4)
+
+/* CFG_GDSCR */
+#define GDSC_POWER_UP_COMPLETE BIT(16)
+#define GDSC_POWER_DOWN_COMPLETE BIT(15)
+#define GDSC_RETAIN_FF_ENABLE BIT(11)
+#define CFG_GDSCR_OFFSET 0x4
+
+/* Wait 2^n CXO cycles between all states. Here, n=2 (4 cycles). */
+#define EN_REST_WAIT_VAL 0x2
+#define EN_FEW_WAIT_VAL 0x8
+#define CLK_DIS_WAIT_VAL 0x2
+
+/* Transition delay shifts */
+#define EN_REST_WAIT_SHIFT 20
+#define EN_FEW_WAIT_SHIFT 16
+#define CLK_DIS_WAIT_SHIFT 12
+
+#define RETAIN_MEM BIT(14)
+#define RETAIN_PERIPH BIT(13)
+
+#define TIMEOUT_US 500
+
+#define domain_to_gdsc(domain) container_of(domain, struct gdsc, pd)
+
+enum gdsc_status {
+ GDSC_OFF,
+ GDSC_ON
+};
+
+/* Returns 1 if GDSC status is status, 0 if not, and < 0 on error */
+static int gdsc_check_status(struct gdsc *sc, enum gdsc_status status)
+{
+ unsigned int reg;
+ u32 val;
+ int ret;
+
+ if (sc->flags & POLL_CFG_GDSCR)
+ reg = sc->gdscr + CFG_GDSCR_OFFSET;
+ else if (sc->gds_hw_ctrl)
+ reg = sc->gds_hw_ctrl;
+ else
+ reg = sc->gdscr;
+
+ ret = regmap_read(sc->regmap, reg, &val);
+ if (ret)
+ return ret;
+
+ if (sc->flags & POLL_CFG_GDSCR) {
+ switch (status) {
+ case GDSC_ON:
+ return !!(val & GDSC_POWER_UP_COMPLETE);
+ case GDSC_OFF:
+ return !!(val & GDSC_POWER_DOWN_COMPLETE);
+ }
+ }
+
+ switch (status) {
+ case GDSC_ON:
+ return !!(val & PWR_ON_MASK);
+ case GDSC_OFF:
+ return !(val & PWR_ON_MASK);
+ }
+
+ return -EINVAL;
+}
+
+static int gdsc_hwctrl(struct gdsc *sc, bool en)
+{
+ u32 val = en ? HW_CONTROL_MASK : 0;
+
+ return regmap_update_bits(sc->regmap, sc->gdscr, HW_CONTROL_MASK, val);
+}
+
+static int gdsc_poll_status(struct gdsc *sc, enum gdsc_status status)
+{
+ ktime_t start;
+
+ start = ktime_get();
+ do {
+ if (gdsc_check_status(sc, status))
+ return 0;
+ } while (ktime_us_delta(ktime_get(), start) < TIMEOUT_US);
+
+ if (gdsc_check_status(sc, status))
+ return 0;
+
+ return -ETIMEDOUT;
+}
+
+static int gdsc_update_collapse_bit(struct gdsc *sc, bool val)
+{
+ u32 reg, mask;
+ int ret;
+
+ if (sc->collapse_mask) {
+ reg = sc->collapse_ctrl;
+ mask = sc->collapse_mask;
+ } else {
+ reg = sc->gdscr;
+ mask = SW_COLLAPSE_MASK;
+ }
+
+ ret = regmap_update_bits(sc->regmap, reg, mask, val ? mask : 0);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int gdsc_toggle_logic(struct gdsc *sc, enum gdsc_status status)
+{
+ int ret;
+
+ if (status == GDSC_ON && sc->rsupply) {
+ ret = regulator_enable(sc->rsupply);
+ if (ret < 0)
+ return ret;
+ }
+
+ ret = gdsc_update_collapse_bit(sc, status == GDSC_OFF);
+
+ /* If disabling votable gdscs, don't poll on status */
+ if ((sc->flags & VOTABLE) && status == GDSC_OFF) {
+ /*
+ * Add a short delay here to ensure that an enable
+ * right after it was disabled does not put it in an
+ * unknown state
+ */
+ udelay(TIMEOUT_US);
+ return 0;
+ }
+
+ if (sc->gds_hw_ctrl) {
+ /*
+ * The gds hw controller asserts/de-asserts the status bit soon
+ * after it receives a power on/off request from a master.
+ * The controller then takes around 8 xo cycles to start its
+ * internal state machine and update the status bit. During
+ * this time, the status bit does not reflect the true status
+ * of the core.
+ * Add a delay of 1 us between writing to the SW_COLLAPSE bit
+ * and polling the status bit.
+ */
+ udelay(1);
+ }
+
+ ret = gdsc_poll_status(sc, status);
+ WARN(ret, "%s status stuck at 'o%s'", sc->pd.name, status ? "ff" : "n");
+
+ if (!ret && status == GDSC_OFF && sc->rsupply) {
+ ret = regulator_disable(sc->rsupply);
+ if (ret < 0)
+ return ret;
+ }
+
+ return ret;
+}
+
+static inline int gdsc_deassert_reset(struct gdsc *sc)
+{
+ int i;
+
+ for (i = 0; i < sc->reset_count; i++)
+ sc->rcdev->ops->deassert(sc->rcdev, sc->resets[i]);
+ return 0;
+}
+
+static inline int gdsc_assert_reset(struct gdsc *sc)
+{
+ int i;
+
+ for (i = 0; i < sc->reset_count; i++)
+ sc->rcdev->ops->assert(sc->rcdev, sc->resets[i]);
+ return 0;
+}
+
+static inline void gdsc_force_mem_on(struct gdsc *sc)
+{
+ int i;
+ u32 mask = RETAIN_MEM;
+
+ if (!(sc->flags & NO_RET_PERIPH))
+ mask |= RETAIN_PERIPH;
+
+ for (i = 0; i < sc->cxc_count; i++)
+ regmap_update_bits(sc->regmap, sc->cxcs[i], mask, mask);
+}
+
+static inline void gdsc_clear_mem_on(struct gdsc *sc)
+{
+ int i;
+ u32 mask = RETAIN_MEM;
+
+ if (!(sc->flags & NO_RET_PERIPH))
+ mask |= RETAIN_PERIPH;
+
+ for (i = 0; i < sc->cxc_count; i++)
+ regmap_update_bits(sc->regmap, sc->cxcs[i], mask, 0);
+}
+
+static inline void gdsc_deassert_clamp_io(struct gdsc *sc)
+{
+ regmap_update_bits(sc->regmap, sc->clamp_io_ctrl,
+ GMEM_CLAMP_IO_MASK, 0);
+}
+
+static inline void gdsc_assert_clamp_io(struct gdsc *sc)
+{
+ regmap_update_bits(sc->regmap, sc->clamp_io_ctrl,
+ GMEM_CLAMP_IO_MASK, 1);
+}
+
+static inline void gdsc_assert_reset_aon(struct gdsc *sc)
+{
+ regmap_update_bits(sc->regmap, sc->clamp_io_ctrl,
+ GMEM_RESET_MASK, 1);
+ udelay(1);
+ regmap_update_bits(sc->regmap, sc->clamp_io_ctrl,
+ GMEM_RESET_MASK, 0);
+}
+
+static void gdsc_retain_ff_on(struct gdsc *sc)
+{
+ u32 mask = GDSC_RETAIN_FF_ENABLE;
+
+ regmap_update_bits(sc->regmap, sc->gdscr, mask, mask);
+}
+
+static int gdsc_enable(struct generic_pm_domain *domain)
+{
+ struct gdsc *sc = domain_to_gdsc(domain);
+ int ret;
+
+ if (sc->pwrsts == PWRSTS_ON)
+ return gdsc_deassert_reset(sc);
+
+ if (sc->flags & SW_RESET) {
+ gdsc_assert_reset(sc);
+ udelay(1);
+ gdsc_deassert_reset(sc);
+ }
+
+ if (sc->flags & CLAMP_IO) {
+ if (sc->flags & AON_RESET)
+ gdsc_assert_reset_aon(sc);
+ gdsc_deassert_clamp_io(sc);
+ }
+
+ ret = gdsc_toggle_logic(sc, GDSC_ON);
+ if (ret)
+ return ret;
+
+ if (sc->pwrsts & PWRSTS_OFF)
+ gdsc_force_mem_on(sc);
+
+ /*
+ * If clocks to this power domain were already on, they will take an
+ * additional 4 clock cycles to re-enable after the power domain is
+ * enabled. Delay to account for this. A delay is also needed to ensure
+ * clocks are not enabled within 400ns of enabling power to the
+ * memories.
+ */
+ udelay(1);
+
+ /* Turn on HW trigger mode if supported */
+ if (sc->flags & HW_CTRL) {
+ ret = gdsc_hwctrl(sc, true);
+ if (ret)
+ return ret;
+ /*
+ * Wait for the GDSC to go through a power down and
+ * up cycle. In case a firmware ends up polling status
+ * bits for the gdsc, it might read an 'on' status before
+ * the GDSC can finish the power cycle.
+ * We wait 1us before returning to ensure the firmware
+ * can't immediately poll the status bits.
+ */
+ udelay(1);
+ }
+
+ if (sc->flags & RETAIN_FF_ENABLE)
+ gdsc_retain_ff_on(sc);
+
+ return 0;
+}
+
+static int gdsc_disable(struct generic_pm_domain *domain)
+{
+ struct gdsc *sc = domain_to_gdsc(domain);
+ int ret;
+
+ if (sc->pwrsts == PWRSTS_ON)
+ return gdsc_assert_reset(sc);
+
+ /* Turn off HW trigger mode if supported */
+ if (sc->flags & HW_CTRL) {
+ ret = gdsc_hwctrl(sc, false);
+ if (ret < 0)
+ return ret;
+ /*
+ * Wait for the GDSC to go through a power down and
+ * up cycle. In case we end up polling status
+ * bits for the gdsc before the power cycle is completed
+ * it might read an 'on' status wrongly.
+ */
+ udelay(1);
+
+ ret = gdsc_poll_status(sc, GDSC_ON);
+ if (ret)
+ return ret;
+ }
+
+ if (sc->pwrsts & PWRSTS_OFF)
+ gdsc_clear_mem_on(sc);
+
+ /*
+ * If the GDSC supports only a Retention state, apart from ON,
+ * leave it in ON state.
+ * There is no SW control to transition the GDSC into
+ * Retention state. This happens in HW when the parent
+ * domain goes down to a Low power state
+ */
+ if (sc->pwrsts == PWRSTS_RET_ON)
+ return 0;
+
+ ret = gdsc_toggle_logic(sc, GDSC_OFF);
+ if (ret)
+ return ret;
+
+ if (sc->flags & CLAMP_IO)
+ gdsc_assert_clamp_io(sc);
+
+ return 0;
+}
+
+static int gdsc_init(struct gdsc *sc)
+{
+ u32 mask, val;
+ int on, ret;
+
+ /*
+ * Disable HW trigger: collapse/restore occur based on registers writes.
+ * Disable SW override: Use hardware state-machine for sequencing.
+ * Configure wait time between states.
+ */
+ mask = HW_CONTROL_MASK | SW_OVERRIDE_MASK |
+ EN_REST_WAIT_MASK | EN_FEW_WAIT_MASK | CLK_DIS_WAIT_MASK;
+
+ if (!sc->en_rest_wait_val)
+ sc->en_rest_wait_val = EN_REST_WAIT_VAL;
+ if (!sc->en_few_wait_val)
+ sc->en_few_wait_val = EN_FEW_WAIT_VAL;
+ if (!sc->clk_dis_wait_val)
+ sc->clk_dis_wait_val = CLK_DIS_WAIT_VAL;
+
+ val = sc->en_rest_wait_val << EN_REST_WAIT_SHIFT |
+ sc->en_few_wait_val << EN_FEW_WAIT_SHIFT |
+ sc->clk_dis_wait_val << CLK_DIS_WAIT_SHIFT;
+
+ ret = regmap_update_bits(sc->regmap, sc->gdscr, mask, val);
+ if (ret)
+ return ret;
+
+ /* Force gdsc ON if only ON state is supported */
+ if (sc->pwrsts == PWRSTS_ON) {
+ ret = gdsc_toggle_logic(sc, GDSC_ON);
+ if (ret)
+ return ret;
+ }
+
+ on = gdsc_check_status(sc, GDSC_ON);
+ if (on < 0)
+ return on;
+
+ if (on) {
+ /* The regulator must be on, sync the kernel state */
+ if (sc->rsupply) {
+ ret = regulator_enable(sc->rsupply);
+ if (ret < 0)
+ return ret;
+ }
+
+ /*
+ * Votable GDSCs can be ON due to Vote from other masters.
+ * If a Votable GDSC is ON, make sure we have a Vote.
+ */
+ if (sc->flags & VOTABLE) {
+ ret = gdsc_update_collapse_bit(sc, false);
+ if (ret)
+ goto err_disable_supply;
+ }
+
+ /* Turn on HW trigger mode if supported */
+ if (sc->flags & HW_CTRL) {
+ ret = gdsc_hwctrl(sc, true);
+ if (ret < 0)
+ goto err_disable_supply;
+ }
+
+ /*
+ * Make sure the retain bit is set if the GDSC is already on,
+ * otherwise we end up turning off the GDSC and destroying all
+ * the register contents that we thought we were saving.
+ */
+ if (sc->flags & RETAIN_FF_ENABLE)
+ gdsc_retain_ff_on(sc);
+ } else if (sc->flags & ALWAYS_ON) {
+ /* If ALWAYS_ON GDSCs are not ON, turn them ON */
+ gdsc_enable(&sc->pd);
+ on = true;
+ }
+
+ if (on || (sc->pwrsts & PWRSTS_RET))
+ gdsc_force_mem_on(sc);
+ else
+ gdsc_clear_mem_on(sc);
+
+ if (sc->flags & ALWAYS_ON)
+ sc->pd.flags |= GENPD_FLAG_ALWAYS_ON;
+ if (!sc->pd.power_off)
+ sc->pd.power_off = gdsc_disable;
+ if (!sc->pd.power_on)
+ sc->pd.power_on = gdsc_enable;
+
+ ret = pm_genpd_init(&sc->pd, NULL, !on);
+ if (ret)
+ goto err_disable_supply;
+
+ return 0;
+
+err_disable_supply:
+ if (on && sc->rsupply)
+ regulator_disable(sc->rsupply);
+
+ return ret;
+}
+
+int gdsc_register(struct gdsc_desc *desc,
+ struct reset_controller_dev *rcdev, struct regmap *regmap)
+{
+ int i, ret;
+ struct genpd_onecell_data *data;
+ struct device *dev = desc->dev;
+ struct gdsc **scs = desc->scs;
+ size_t num = desc->num;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->domains = devm_kcalloc(dev, num, sizeof(*data->domains),
+ GFP_KERNEL);
+ if (!data->domains)
+ return -ENOMEM;
+
+ for (i = 0; i < num; i++) {
+ if (!scs[i] || !scs[i]->supply)
+ continue;
+
+ scs[i]->rsupply = devm_regulator_get(dev, scs[i]->supply);
+ if (IS_ERR(scs[i]->rsupply))
+ return PTR_ERR(scs[i]->rsupply);
+ }
+
+ data->num_domains = num;
+ for (i = 0; i < num; i++) {
+ if (!scs[i])
+ continue;
+ scs[i]->regmap = regmap;
+ scs[i]->rcdev = rcdev;
+ ret = gdsc_init(scs[i]);
+ if (ret)
+ return ret;
+ data->domains[i] = &scs[i]->pd;
+ }
+
+ /* Add subdomains */
+ for (i = 0; i < num; i++) {
+ if (!scs[i])
+ continue;
+ if (scs[i]->parent)
+ pm_genpd_add_subdomain(scs[i]->parent, &scs[i]->pd);
+ else if (!IS_ERR_OR_NULL(dev->pm_domain))
+ pm_genpd_add_subdomain(pd_to_genpd(dev->pm_domain), &scs[i]->pd);
+ }
+
+ return of_genpd_add_provider_onecell(dev->of_node, data);
+}
+
+void gdsc_unregister(struct gdsc_desc *desc)
+{
+ int i;
+ struct device *dev = desc->dev;
+ struct gdsc **scs = desc->scs;
+ size_t num = desc->num;
+
+ /* Remove subdomains */
+ for (i = 0; i < num; i++) {
+ if (!scs[i])
+ continue;
+ if (scs[i]->parent)
+ pm_genpd_remove_subdomain(scs[i]->parent, &scs[i]->pd);
+ else if (!IS_ERR_OR_NULL(dev->pm_domain))
+ pm_genpd_remove_subdomain(pd_to_genpd(dev->pm_domain), &scs[i]->pd);
+ }
+ of_genpd_del_provider(dev->of_node);
+}
+
+/*
+ * On SDM845+ the GPU GX domain is *almost* entirely controlled by the GMU
+ * running in the CX domain so the CPU doesn't need to know anything about the
+ * GX domain EXCEPT....
+ *
+ * Hardware constraints dictate that the GX be powered down before the CX. If
+ * the GMU crashes it could leave the GX on. In order to successfully bring back
+ * the device the CPU needs to disable the GX headswitch. There being no sane
+ * way to reach in and touch that register from deep inside the GPU driver we
+ * need to set up the infrastructure to be able to ensure that the GPU can
+ * ensure that the GX is off during this super special case. We do this by
+ * defining a GX gdsc with a dummy enable function and a "default" disable
+ * function.
+ *
+ * This allows us to attach with genpd_dev_pm_attach_by_name() in the GPU
+ * driver. During power up, nothing will happen from the CPU (and the GMU will
+ * power up normally but during power down this will ensure that the GX domain
+ * is *really* off - this gives us a semi standard way of doing what we need.
+ */
+int gdsc_gx_do_nothing_enable(struct generic_pm_domain *domain)
+{
+ /* Do nothing but give genpd the impression that we were successful */
+ return 0;
+}
+EXPORT_SYMBOL_GPL(gdsc_gx_do_nothing_enable);