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path: root/drivers/clk/imx/clk-sscg-pll.c
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-rw-r--r--drivers/clk/imx/clk-sscg-pll.c540
1 files changed, 540 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-sscg-pll.c b/drivers/clk/imx/clk-sscg-pll.c
new file mode 100644
index 000000000..81f304fae
--- /dev/null
+++ b/drivers/clk/imx/clk-sscg-pll.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Copyright 2018 NXP.
+ *
+ * This driver supports the SCCG plls found in the imx8m SOCs
+ *
+ * Documentation for this SCCG pll can be found at:
+ * https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf#page=834
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/slab.h>
+#include <linux/bitfield.h>
+
+#include "clk.h"
+
+/* PLL CFGs */
+#define PLL_CFG0 0x0
+#define PLL_CFG1 0x4
+#define PLL_CFG2 0x8
+
+#define PLL_DIVF1_MASK GENMASK(18, 13)
+#define PLL_DIVF2_MASK GENMASK(12, 7)
+#define PLL_DIVR1_MASK GENMASK(27, 25)
+#define PLL_DIVR2_MASK GENMASK(24, 19)
+#define PLL_DIVQ_MASK GENMASK(6, 1)
+#define PLL_REF_MASK GENMASK(2, 0)
+
+#define PLL_LOCK_MASK BIT(31)
+#define PLL_PD_MASK BIT(7)
+
+/* These are the specification limits for the SSCG PLL */
+#define PLL_REF_MIN_FREQ 25000000UL
+#define PLL_REF_MAX_FREQ 235000000UL
+
+#define PLL_STAGE1_MIN_FREQ 1600000000UL
+#define PLL_STAGE1_MAX_FREQ 2400000000UL
+
+#define PLL_STAGE1_REF_MIN_FREQ 25000000UL
+#define PLL_STAGE1_REF_MAX_FREQ 54000000UL
+
+#define PLL_STAGE2_MIN_FREQ 1200000000UL
+#define PLL_STAGE2_MAX_FREQ 2400000000UL
+
+#define PLL_STAGE2_REF_MIN_FREQ 54000000UL
+#define PLL_STAGE2_REF_MAX_FREQ 75000000UL
+
+#define PLL_OUT_MIN_FREQ 20000000UL
+#define PLL_OUT_MAX_FREQ 1200000000UL
+
+#define PLL_DIVR1_MAX 7
+#define PLL_DIVR2_MAX 63
+#define PLL_DIVF1_MAX 63
+#define PLL_DIVF2_MAX 63
+#define PLL_DIVQ_MAX 63
+
+#define PLL_BYPASS_NONE 0x0
+#define PLL_BYPASS1 0x2
+#define PLL_BYPASS2 0x1
+
+#define SSCG_PLL_BYPASS1_MASK BIT(5)
+#define SSCG_PLL_BYPASS2_MASK BIT(4)
+#define SSCG_PLL_BYPASS_MASK GENMASK(5, 4)
+
+#define PLL_SCCG_LOCK_TIMEOUT 70
+
+struct clk_sscg_pll_setup {
+ int divr1, divf1;
+ int divr2, divf2;
+ int divq;
+ int bypass;
+ uint64_t vco1;
+ uint64_t vco2;
+ uint64_t fout;
+ uint64_t ref;
+ uint64_t ref_div1;
+ uint64_t ref_div2;
+ uint64_t fout_request;
+ int fout_error;
+};
+
+struct clk_sscg_pll {
+ struct clk_hw hw;
+ const struct clk_ops ops;
+ void __iomem *base;
+ struct clk_sscg_pll_setup setup;
+ u8 parent;
+ u8 bypass1;
+ u8 bypass2;
+};
+
+#define to_clk_sscg_pll(_hw) container_of(_hw, struct clk_sscg_pll, hw)
+
+static int clk_sscg_pll_wait_lock(struct clk_sscg_pll *pll)
+{
+ u32 val;
+
+ val = readl_relaxed(pll->base + PLL_CFG0);
+
+ /* don't wait for lock if all plls are bypassed */
+ if (!(val & SSCG_PLL_BYPASS2_MASK))
+ return readl_poll_timeout(pll->base, val, val & PLL_LOCK_MASK,
+ 0, PLL_SCCG_LOCK_TIMEOUT);
+
+ return 0;
+}
+
+static int clk_sscg_pll2_check_match(struct clk_sscg_pll_setup *setup,
+ struct clk_sscg_pll_setup *temp_setup)
+{
+ int new_diff = temp_setup->fout - temp_setup->fout_request;
+ int diff = temp_setup->fout_error;
+
+ if (abs(diff) > abs(new_diff)) {
+ temp_setup->fout_error = new_diff;
+ memcpy(setup, temp_setup, sizeof(struct clk_sscg_pll_setup));
+
+ if (temp_setup->fout_request == temp_setup->fout)
+ return 0;
+ }
+ return -1;
+}
+
+static int clk_sscg_divq_lookup(struct clk_sscg_pll_setup *setup,
+ struct clk_sscg_pll_setup *temp_setup)
+{
+ int ret = -EINVAL;
+
+ for (temp_setup->divq = 0; temp_setup->divq <= PLL_DIVQ_MAX;
+ temp_setup->divq++) {
+ temp_setup->vco2 = temp_setup->vco1;
+ do_div(temp_setup->vco2, temp_setup->divr2 + 1);
+ temp_setup->vco2 *= 2;
+ temp_setup->vco2 *= temp_setup->divf2 + 1;
+ if (temp_setup->vco2 >= PLL_STAGE2_MIN_FREQ &&
+ temp_setup->vco2 <= PLL_STAGE2_MAX_FREQ) {
+ temp_setup->fout = temp_setup->vco2;
+ do_div(temp_setup->fout, 2 * (temp_setup->divq + 1));
+
+ ret = clk_sscg_pll2_check_match(setup, temp_setup);
+ if (!ret) {
+ temp_setup->bypass = PLL_BYPASS1;
+ return ret;
+ }
+ }
+ }
+
+ return ret;
+}
+
+static int clk_sscg_divf2_lookup(struct clk_sscg_pll_setup *setup,
+ struct clk_sscg_pll_setup *temp_setup)
+{
+ int ret = -EINVAL;
+
+ for (temp_setup->divf2 = 0; temp_setup->divf2 <= PLL_DIVF2_MAX;
+ temp_setup->divf2++) {
+ ret = clk_sscg_divq_lookup(setup, temp_setup);
+ if (!ret)
+ return ret;
+ }
+
+ return ret;
+}
+
+static int clk_sscg_divr2_lookup(struct clk_sscg_pll_setup *setup,
+ struct clk_sscg_pll_setup *temp_setup)
+{
+ int ret = -EINVAL;
+
+ for (temp_setup->divr2 = 0; temp_setup->divr2 <= PLL_DIVR2_MAX;
+ temp_setup->divr2++) {
+ temp_setup->ref_div2 = temp_setup->vco1;
+ do_div(temp_setup->ref_div2, temp_setup->divr2 + 1);
+ if (temp_setup->ref_div2 >= PLL_STAGE2_REF_MIN_FREQ &&
+ temp_setup->ref_div2 <= PLL_STAGE2_REF_MAX_FREQ) {
+ ret = clk_sscg_divf2_lookup(setup, temp_setup);
+ if (!ret)
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+static int clk_sscg_pll2_find_setup(struct clk_sscg_pll_setup *setup,
+ struct clk_sscg_pll_setup *temp_setup,
+ uint64_t ref)
+{
+ int ret;
+
+ if (ref < PLL_STAGE1_MIN_FREQ || ref > PLL_STAGE1_MAX_FREQ)
+ return -EINVAL;
+
+ temp_setup->vco1 = ref;
+
+ ret = clk_sscg_divr2_lookup(setup, temp_setup);
+ return ret;
+}
+
+static int clk_sscg_divf1_lookup(struct clk_sscg_pll_setup *setup,
+ struct clk_sscg_pll_setup *temp_setup)
+{
+ int ret = -EINVAL;
+
+ for (temp_setup->divf1 = 0; temp_setup->divf1 <= PLL_DIVF1_MAX;
+ temp_setup->divf1++) {
+ uint64_t vco1 = temp_setup->ref;
+
+ do_div(vco1, temp_setup->divr1 + 1);
+ vco1 *= 2;
+ vco1 *= temp_setup->divf1 + 1;
+
+ ret = clk_sscg_pll2_find_setup(setup, temp_setup, vco1);
+ if (!ret) {
+ temp_setup->bypass = PLL_BYPASS_NONE;
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+static int clk_sscg_divr1_lookup(struct clk_sscg_pll_setup *setup,
+ struct clk_sscg_pll_setup *temp_setup)
+{
+ int ret = -EINVAL;
+
+ for (temp_setup->divr1 = 0; temp_setup->divr1 <= PLL_DIVR1_MAX;
+ temp_setup->divr1++) {
+ temp_setup->ref_div1 = temp_setup->ref;
+ do_div(temp_setup->ref_div1, temp_setup->divr1 + 1);
+ if (temp_setup->ref_div1 >= PLL_STAGE1_REF_MIN_FREQ &&
+ temp_setup->ref_div1 <= PLL_STAGE1_REF_MAX_FREQ) {
+ ret = clk_sscg_divf1_lookup(setup, temp_setup);
+ if (!ret)
+ return ret;
+ }
+ }
+
+ return ret;
+}
+
+static int clk_sscg_pll1_find_setup(struct clk_sscg_pll_setup *setup,
+ struct clk_sscg_pll_setup *temp_setup,
+ uint64_t ref)
+{
+ int ret;
+
+ if (ref < PLL_REF_MIN_FREQ || ref > PLL_REF_MAX_FREQ)
+ return -EINVAL;
+
+ temp_setup->ref = ref;
+
+ ret = clk_sscg_divr1_lookup(setup, temp_setup);
+
+ return ret;
+}
+
+static int clk_sscg_pll_find_setup(struct clk_sscg_pll_setup *setup,
+ uint64_t prate,
+ uint64_t rate, int try_bypass)
+{
+ struct clk_sscg_pll_setup temp_setup;
+ int ret = -EINVAL;
+
+ memset(&temp_setup, 0, sizeof(struct clk_sscg_pll_setup));
+ memset(setup, 0, sizeof(struct clk_sscg_pll_setup));
+
+ temp_setup.fout_error = PLL_OUT_MAX_FREQ;
+ temp_setup.fout_request = rate;
+
+ switch (try_bypass) {
+ case PLL_BYPASS2:
+ if (prate == rate) {
+ setup->bypass = PLL_BYPASS2;
+ setup->fout = rate;
+ ret = 0;
+ }
+ break;
+ case PLL_BYPASS1:
+ ret = clk_sscg_pll2_find_setup(setup, &temp_setup, prate);
+ break;
+ case PLL_BYPASS_NONE:
+ ret = clk_sscg_pll1_find_setup(setup, &temp_setup, prate);
+ break;
+ }
+
+ return ret;
+}
+
+static int clk_sscg_pll_is_prepared(struct clk_hw *hw)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+
+ u32 val = readl_relaxed(pll->base + PLL_CFG0);
+
+ return (val & PLL_PD_MASK) ? 0 : 1;
+}
+
+static int clk_sscg_pll_prepare(struct clk_hw *hw)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+ u32 val;
+
+ val = readl_relaxed(pll->base + PLL_CFG0);
+ val &= ~PLL_PD_MASK;
+ writel_relaxed(val, pll->base + PLL_CFG0);
+
+ return clk_sscg_pll_wait_lock(pll);
+}
+
+static void clk_sscg_pll_unprepare(struct clk_hw *hw)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+ u32 val;
+
+ val = readl_relaxed(pll->base + PLL_CFG0);
+ val |= PLL_PD_MASK;
+ writel_relaxed(val, pll->base + PLL_CFG0);
+}
+
+static unsigned long clk_sscg_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+ u32 val, divr1, divf1, divr2, divf2, divq;
+ u64 temp64;
+
+ val = readl_relaxed(pll->base + PLL_CFG2);
+ divr1 = FIELD_GET(PLL_DIVR1_MASK, val);
+ divr2 = FIELD_GET(PLL_DIVR2_MASK, val);
+ divf1 = FIELD_GET(PLL_DIVF1_MASK, val);
+ divf2 = FIELD_GET(PLL_DIVF2_MASK, val);
+ divq = FIELD_GET(PLL_DIVQ_MASK, val);
+
+ temp64 = parent_rate;
+
+ val = readl(pll->base + PLL_CFG0);
+ if (val & SSCG_PLL_BYPASS2_MASK) {
+ temp64 = parent_rate;
+ } else if (val & SSCG_PLL_BYPASS1_MASK) {
+ temp64 *= divf2;
+ do_div(temp64, (divr2 + 1) * (divq + 1));
+ } else {
+ temp64 *= 2;
+ temp64 *= (divf1 + 1) * (divf2 + 1);
+ do_div(temp64, (divr1 + 1) * (divr2 + 1) * (divq + 1));
+ }
+
+ return temp64;
+}
+
+static int clk_sscg_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+ struct clk_sscg_pll_setup *setup = &pll->setup;
+ u32 val;
+
+ /* set bypass here too since the parent might be the same */
+ val = readl(pll->base + PLL_CFG0);
+ val &= ~SSCG_PLL_BYPASS_MASK;
+ val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, setup->bypass);
+ writel(val, pll->base + PLL_CFG0);
+
+ val = readl_relaxed(pll->base + PLL_CFG2);
+ val &= ~(PLL_DIVF1_MASK | PLL_DIVF2_MASK);
+ val &= ~(PLL_DIVR1_MASK | PLL_DIVR2_MASK | PLL_DIVQ_MASK);
+ val |= FIELD_PREP(PLL_DIVF1_MASK, setup->divf1);
+ val |= FIELD_PREP(PLL_DIVF2_MASK, setup->divf2);
+ val |= FIELD_PREP(PLL_DIVR1_MASK, setup->divr1);
+ val |= FIELD_PREP(PLL_DIVR2_MASK, setup->divr2);
+ val |= FIELD_PREP(PLL_DIVQ_MASK, setup->divq);
+ writel_relaxed(val, pll->base + PLL_CFG2);
+
+ return clk_sscg_pll_wait_lock(pll);
+}
+
+static u8 clk_sscg_pll_get_parent(struct clk_hw *hw)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+ u32 val;
+ u8 ret = pll->parent;
+
+ val = readl(pll->base + PLL_CFG0);
+ if (val & SSCG_PLL_BYPASS2_MASK)
+ ret = pll->bypass2;
+ else if (val & SSCG_PLL_BYPASS1_MASK)
+ ret = pll->bypass1;
+ return ret;
+}
+
+static int clk_sscg_pll_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+ u32 val;
+
+ val = readl(pll->base + PLL_CFG0);
+ val &= ~SSCG_PLL_BYPASS_MASK;
+ val |= FIELD_PREP(SSCG_PLL_BYPASS_MASK, pll->setup.bypass);
+ writel(val, pll->base + PLL_CFG0);
+
+ return clk_sscg_pll_wait_lock(pll);
+}
+
+static int __clk_sscg_pll_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req,
+ uint64_t min,
+ uint64_t max,
+ uint64_t rate,
+ int bypass)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+ struct clk_sscg_pll_setup *setup = &pll->setup;
+ struct clk_hw *parent_hw = NULL;
+ int bypass_parent_index;
+ int ret;
+
+ req->max_rate = max;
+ req->min_rate = min;
+
+ switch (bypass) {
+ case PLL_BYPASS2:
+ bypass_parent_index = pll->bypass2;
+ break;
+ case PLL_BYPASS1:
+ bypass_parent_index = pll->bypass1;
+ break;
+ default:
+ bypass_parent_index = pll->parent;
+ break;
+ }
+
+ parent_hw = clk_hw_get_parent_by_index(hw, bypass_parent_index);
+ ret = __clk_determine_rate(parent_hw, req);
+ if (!ret) {
+ ret = clk_sscg_pll_find_setup(setup, req->rate,
+ rate, bypass);
+ }
+
+ req->best_parent_hw = parent_hw;
+ req->best_parent_rate = req->rate;
+ req->rate = setup->fout;
+
+ return ret;
+}
+
+static int clk_sscg_pll_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct clk_sscg_pll *pll = to_clk_sscg_pll(hw);
+ struct clk_sscg_pll_setup *setup = &pll->setup;
+ uint64_t rate = req->rate;
+ uint64_t min = req->min_rate;
+ uint64_t max = req->max_rate;
+ int ret;
+
+ if (rate < PLL_OUT_MIN_FREQ || rate > PLL_OUT_MAX_FREQ)
+ return -EINVAL;
+
+ ret = __clk_sscg_pll_determine_rate(hw, req, req->rate, req->rate,
+ rate, PLL_BYPASS2);
+ if (!ret)
+ return ret;
+
+ ret = __clk_sscg_pll_determine_rate(hw, req, PLL_STAGE1_REF_MIN_FREQ,
+ PLL_STAGE1_REF_MAX_FREQ, rate,
+ PLL_BYPASS1);
+ if (!ret)
+ return ret;
+
+ ret = __clk_sscg_pll_determine_rate(hw, req, PLL_REF_MIN_FREQ,
+ PLL_REF_MAX_FREQ, rate,
+ PLL_BYPASS_NONE);
+ if (!ret)
+ return ret;
+
+ if (setup->fout >= min && setup->fout <= max)
+ ret = 0;
+
+ return ret;
+}
+
+static const struct clk_ops clk_sscg_pll_ops = {
+ .prepare = clk_sscg_pll_prepare,
+ .unprepare = clk_sscg_pll_unprepare,
+ .is_prepared = clk_sscg_pll_is_prepared,
+ .recalc_rate = clk_sscg_pll_recalc_rate,
+ .set_rate = clk_sscg_pll_set_rate,
+ .set_parent = clk_sscg_pll_set_parent,
+ .get_parent = clk_sscg_pll_get_parent,
+ .determine_rate = clk_sscg_pll_determine_rate,
+};
+
+struct clk_hw *imx_clk_hw_sscg_pll(const char *name,
+ const char * const *parent_names,
+ u8 num_parents,
+ u8 parent, u8 bypass1, u8 bypass2,
+ void __iomem *base,
+ unsigned long flags)
+{
+ struct clk_sscg_pll *pll;
+ struct clk_init_data init;
+ struct clk_hw *hw;
+ int ret;
+
+ pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+ if (!pll)
+ return ERR_PTR(-ENOMEM);
+
+ pll->parent = parent;
+ pll->bypass1 = bypass1;
+ pll->bypass2 = bypass2;
+
+ pll->base = base;
+ init.name = name;
+ init.ops = &clk_sscg_pll_ops;
+
+ init.flags = flags;
+ init.parent_names = parent_names;
+ init.num_parents = num_parents;
+
+ pll->hw.init = &init;
+
+ hw = &pll->hw;
+
+ ret = clk_hw_register(NULL, hw);
+ if (ret) {
+ kfree(pll);
+ return ERR_PTR(ret);
+ }
+
+ return hw;
+}
+EXPORT_SYMBOL_GPL(imx_clk_hw_sscg_pll);
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