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path: root/drivers/clk/clk-plldig.c
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-rw-r--r--drivers/clk/clk-plldig.c286
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/clk/clk-plldig.c b/drivers/clk/clk-plldig.c
new file mode 100644
index 000000000000..312b8312d503
--- /dev/null
+++ b/drivers/clk/clk-plldig.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 NXP
+ *
+ * Clock driver for LS1028A Display output interfaces(LCD, DPHY).
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/bitfield.h>
+
+/* PLLDIG register offsets and bit masks */
+#define PLLDIG_REG_PLLSR 0x24
+#define PLLDIG_LOCK_MASK BIT(2)
+#define PLLDIG_REG_PLLDV 0x28
+#define PLLDIG_MFD_MASK GENMASK(7, 0)
+#define PLLDIG_RFDPHI1_MASK GENMASK(30, 25)
+#define PLLDIG_REG_PLLFM 0x2c
+#define PLLDIG_SSCGBYP_ENABLE BIT(30)
+#define PLLDIG_REG_PLLFD 0x30
+#define PLLDIG_FDEN BIT(30)
+#define PLLDIG_FRAC_MASK GENMASK(15, 0)
+#define PLLDIG_REG_PLLCAL1 0x38
+#define PLLDIG_REG_PLLCAL2 0x3c
+
+/* Range of the VCO frequencies, in Hz */
+#define PLLDIG_MIN_VCO_FREQ 650000000
+#define PLLDIG_MAX_VCO_FREQ 1300000000
+
+/* Range of the output frequencies, in Hz */
+#define PHI1_MIN_FREQ 27000000UL
+#define PHI1_MAX_FREQ 600000000UL
+
+/* Maximum value of the reduced frequency divider */
+#define MAX_RFDPHI1 63UL
+
+/* Best value of multiplication factor divider */
+#define PLLDIG_DEFAULT_MFD 44
+
+/*
+ * Denominator part of the fractional part of the
+ * loop multiplication factor.
+ */
+#define MFDEN 20480
+
+static const struct clk_parent_data parent_data[] = {
+ { .index = 0 },
+};
+
+struct clk_plldig {
+ struct clk_hw hw;
+ void __iomem *regs;
+ unsigned int vco_freq;
+};
+
+#define to_clk_plldig(_hw) container_of(_hw, struct clk_plldig, hw)
+
+static int plldig_enable(struct clk_hw *hw)
+{
+ struct clk_plldig *data = to_clk_plldig(hw);
+ u32 val;
+
+ val = readl(data->regs + PLLDIG_REG_PLLFM);
+ /*
+ * Use Bypass mode with PLL off by default, the frequency overshoot
+ * detector output was disable. SSCG Bypass mode should be enable.
+ */
+ val |= PLLDIG_SSCGBYP_ENABLE;
+ writel(val, data->regs + PLLDIG_REG_PLLFM);
+
+ return 0;
+}
+
+static void plldig_disable(struct clk_hw *hw)
+{
+ struct clk_plldig *data = to_clk_plldig(hw);
+ u32 val;
+
+ val = readl(data->regs + PLLDIG_REG_PLLFM);
+
+ val &= ~PLLDIG_SSCGBYP_ENABLE;
+ val |= FIELD_PREP(PLLDIG_SSCGBYP_ENABLE, 0x0);
+
+ writel(val, data->regs + PLLDIG_REG_PLLFM);
+}
+
+static int plldig_is_enabled(struct clk_hw *hw)
+{
+ struct clk_plldig *data = to_clk_plldig(hw);
+
+ return readl(data->regs + PLLDIG_REG_PLLFM) &
+ PLLDIG_SSCGBYP_ENABLE;
+}
+
+static unsigned long plldig_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_plldig *data = to_clk_plldig(hw);
+ u32 val, rfdphi1;
+
+ val = readl(data->regs + PLLDIG_REG_PLLDV);
+
+ /* Check if PLL is bypassed */
+ if (val & PLLDIG_SSCGBYP_ENABLE)
+ return parent_rate;
+
+ rfdphi1 = FIELD_GET(PLLDIG_RFDPHI1_MASK, val);
+
+ /*
+ * If RFDPHI1 has a value of 1 the VCO frequency is also divided by
+ * one.
+ */
+ if (!rfdphi1)
+ rfdphi1 = 1;
+
+ return DIV_ROUND_UP(data->vco_freq, rfdphi1);
+}
+
+static unsigned long plldig_calc_target_div(unsigned long vco_freq,
+ unsigned long target_rate)
+{
+ unsigned long div;
+
+ div = DIV_ROUND_CLOSEST(vco_freq, target_rate);
+ div = clamp(div, 1UL, MAX_RFDPHI1);
+
+ return div;
+}
+
+static int plldig_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct clk_plldig *data = to_clk_plldig(hw);
+ unsigned int div;
+
+ req->rate = clamp(req->rate, PHI1_MIN_FREQ, PHI1_MAX_FREQ);
+ div = plldig_calc_target_div(data->vco_freq, req->rate);
+ req->rate = DIV_ROUND_UP(data->vco_freq, div);
+
+ return 0;
+}
+
+static int plldig_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_plldig *data = to_clk_plldig(hw);
+ unsigned int val, cond;
+ unsigned int rfdphi1;
+
+ rate = clamp(rate, PHI1_MIN_FREQ, PHI1_MAX_FREQ);
+ rfdphi1 = plldig_calc_target_div(data->vco_freq, rate);
+
+ /* update the divider value */
+ val = readl(data->regs + PLLDIG_REG_PLLDV);
+ val &= ~PLLDIG_RFDPHI1_MASK;
+ val |= FIELD_PREP(PLLDIG_RFDPHI1_MASK, rfdphi1);
+ writel(val, data->regs + PLLDIG_REG_PLLDV);
+
+ /* waiting for old lock state to clear */
+ udelay(200);
+
+ /* Wait until PLL is locked or timeout */
+ return readl_poll_timeout_atomic(data->regs + PLLDIG_REG_PLLSR, cond,
+ cond & PLLDIG_LOCK_MASK, 0,
+ USEC_PER_MSEC);
+}
+
+static const struct clk_ops plldig_clk_ops = {
+ .enable = plldig_enable,
+ .disable = plldig_disable,
+ .is_enabled = plldig_is_enabled,
+ .recalc_rate = plldig_recalc_rate,
+ .determine_rate = plldig_determine_rate,
+ .set_rate = plldig_set_rate,
+};
+
+static int plldig_init(struct clk_hw *hw)
+{
+ struct clk_plldig *data = to_clk_plldig(hw);
+ struct clk_hw *parent = clk_hw_get_parent(hw);
+ unsigned long parent_rate = clk_hw_get_rate(parent);
+ unsigned long val;
+ unsigned long long lltmp;
+ unsigned int mfd, fracdiv = 0;
+
+ if (!parent)
+ return -EINVAL;
+
+ if (data->vco_freq) {
+ mfd = data->vco_freq / parent_rate;
+ lltmp = data->vco_freq % parent_rate;
+ lltmp *= MFDEN;
+ do_div(lltmp, parent_rate);
+ fracdiv = lltmp;
+ } else {
+ mfd = PLLDIG_DEFAULT_MFD;
+ data->vco_freq = parent_rate * mfd;
+ }
+
+ val = FIELD_PREP(PLLDIG_MFD_MASK, mfd);
+ writel(val, data->regs + PLLDIG_REG_PLLDV);
+
+ /* Enable fractional divider */
+ if (fracdiv) {
+ val = FIELD_PREP(PLLDIG_FRAC_MASK, fracdiv);
+ val |= PLLDIG_FDEN;
+ writel(val, data->regs + PLLDIG_REG_PLLFD);
+ }
+
+ return 0;
+}
+
+static int plldig_clk_probe(struct platform_device *pdev)
+{
+ struct clk_plldig *data;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(data->regs))
+ return PTR_ERR(data->regs);
+
+ data->hw.init = CLK_HW_INIT_PARENTS_DATA("dpclk",
+ parent_data,
+ &plldig_clk_ops,
+ 0);
+
+ ret = devm_clk_hw_register(dev, &data->hw);
+ if (ret) {
+ dev_err(dev, "failed to register %s clock\n",
+ dev->of_node->name);
+ return ret;
+ }
+
+ ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+ &data->hw);
+ if (ret) {
+ dev_err(dev, "unable to add clk provider\n");
+ return ret;
+ }
+
+ /*
+ * The frequency of the VCO cannot be changed during runtime.
+ * Therefore, let the user specify a desired frequency.
+ */
+ if (!of_property_read_u32(dev->of_node, "fsl,vco-hz",
+ &data->vco_freq)) {
+ if (data->vco_freq < PLLDIG_MIN_VCO_FREQ ||
+ data->vco_freq > PLLDIG_MAX_VCO_FREQ)
+ return -EINVAL;
+ }
+
+ return plldig_init(&data->hw);
+}
+
+static const struct of_device_id plldig_clk_id[] = {
+ { .compatible = "fsl,ls1028a-plldig" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, plldig_clk_id);
+
+static struct platform_driver plldig_clk_driver = {
+ .driver = {
+ .name = "plldig-clock",
+ .of_match_table = plldig_clk_id,
+ },
+ .probe = plldig_clk_probe,
+};
+module_platform_driver(plldig_clk_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wen He <wen.he_1@nxp.com>");
+MODULE_DESCRIPTION("LS1028A Display output interface pixel clock driver");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 18:17:12 +0100