* [PATCH v2 2/3] clk: lan966x: Add lan966x SoC clock driver
2021-09-08 11:48 [PATCH v2 0/3] Add driver for lan966x Generic Clock Controlle Kavyasree Kotagiri
2021-09-08 11:48 ` [PATCH v2 1/3] dt-bindings: clock: lan966x: Add binding includes for lan966x SoC clock IDs Kavyasree Kotagiri
@ 2021-09-08 11:48 ` Kavyasree Kotagiri
2021-09-08 11:48 ` [PATCH v2 3/3] dt-bindings: clock: lan966x: Add LAN966X Clock Controller Kavyasree Kotagiri
2 siblings, 0 replies; 5+ messages in thread
From: Kavyasree Kotagiri @ 2021-09-08 11:48 UTC (permalink / raw)
To: robh+dt, mturquette, sboyd
Cc: linux-kernel, devicetree, linux-clk, UNGLinuxDriver,
Eugen.Hristev, Kavyasree.Kotagiri, Manohar.Puri
This adds Generic Clock Controller driver for lan966x SoC.
Lan966x clock controller contains 3 PLLs - cpu_clk, ddr_clk
and sys_clk. It generates and supplies clock to various
peripherals within SoC.
Register settings required to provide GCK clocking to a
peripheral is as below:
GCK_SRC_SEL = Select clock source.
GCK_PRESCALER = Set divider value.
GCK_ENA = 1 - Enable GCK clock.
Signed-off-by: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Co-developed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
v1 -> v2:
- No changes.
drivers/clk/clk-lan966x.c | 235 ++++++++++++++++++++++++++++++++++++++
1 file changed, 235 insertions(+)
create mode 100644 drivers/clk/clk-lan966x.c
diff --git a/drivers/clk/clk-lan966x.c b/drivers/clk/clk-lan966x.c
new file mode 100644
index 000000000000..4492be90cecf
--- /dev/null
+++ b/drivers/clk/clk-lan966x.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Microchip LAN966x SoC Clock driver.
+ *
+ * Copyright (C) 2021 Microchip Technology, Inc. and its subsidiaries
+ *
+ * Author: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/clock/microchip,lan966x.h>
+
+#define GCK_ENA BIT(0)
+#define GCK_SRC_SEL GENMASK(9, 8)
+#define GCK_PRESCALER GENMASK(23, 16)
+
+static const char *clk_names[N_CLOCKS] = {
+ "qspi0", "qspi1", "qspi2", "sdmmc0",
+ "pi", "mcan0", "mcan1", "flexcom0",
+ "flexcom1", "flexcom2", "flexcom3",
+ "flexcom4", "timer", "usb_refclk",
+};
+
+struct lan966x_gck {
+ struct clk_hw hw;
+ void __iomem *reg;
+};
+#define to_lan966x_gck(hw) container_of(hw, struct lan966x_gck, hw)
+
+static struct clk_init_data init;
+static void __iomem *base;
+
+static int lan966x_gck_enable(struct clk_hw *hw)
+{
+ struct lan966x_gck *gck = to_lan966x_gck(hw);
+ u32 val = readl(gck->reg);
+
+ val |= GCK_ENA;
+ writel(val, gck->reg);
+
+ return 0;
+}
+
+static void lan966x_gck_disable(struct clk_hw *hw)
+{
+ struct lan966x_gck *gck = to_lan966x_gck(hw);
+ u32 val = readl(gck->reg);
+
+ val &= ~GCK_ENA;
+ writel(val, gck->reg);
+}
+
+static int lan966x_gck_set_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct lan966x_gck *gck = to_lan966x_gck(hw);
+ u32 div, val = readl(gck->reg);
+
+ if (rate == 0 || parent_rate == 0)
+ return -EINVAL;
+
+ /* Set Prescalar */
+ div = parent_rate / rate;
+ val &= ~GCK_PRESCALER;
+ val |= FIELD_PREP(GCK_PRESCALER, (div - 1));
+ writel(val, gck->reg);
+
+ return 0;
+}
+
+static long lan966x_gck_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ unsigned int div;
+
+ if (rate == 0 || *parent_rate == 0)
+ return -EINVAL;
+
+ if (rate >= *parent_rate)
+ return *parent_rate;
+
+ div = DIV_ROUND_CLOSEST(*parent_rate, rate);
+
+ return *parent_rate / div;
+}
+
+static unsigned long lan966x_gck_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct lan966x_gck *gck = to_lan966x_gck(hw);
+ u32 div, val = readl(gck->reg);
+
+ div = FIELD_GET(GCK_PRESCALER, val);
+
+ return parent_rate / (div + 1);
+}
+
+static int lan966x_gck_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct clk_hw *parent;
+ int i;
+
+ for (i = 0; i < clk_hw_get_num_parents(hw); ++i) {
+ parent = clk_hw_get_parent_by_index(hw, i);
+ if (!parent)
+ continue;
+
+ if (clk_hw_get_rate(parent) / req->rate < 254) {
+ req->best_parent_hw = parent;
+ req->best_parent_rate = clk_hw_get_rate(parent);
+
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static u8 lan966x_gck_get_parent(struct clk_hw *hw)
+{
+ struct lan966x_gck *gck = to_lan966x_gck(hw);
+ u32 val = readl(gck->reg);
+
+ return FIELD_GET(GCK_SRC_SEL, val);
+}
+
+static int lan966x_gck_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct lan966x_gck *gck = to_lan966x_gck(hw);
+ u32 val = readl(gck->reg);
+
+ val &= ~GCK_SRC_SEL;
+ val |= FIELD_PREP(GCK_SRC_SEL, index);
+ writel(val, gck->reg);
+
+ return 0;
+}
+
+static const struct clk_ops lan966x_gck_ops = {
+ .enable = lan966x_gck_enable,
+ .disable = lan966x_gck_disable,
+ .set_rate = lan966x_gck_set_rate,
+ .round_rate = lan966x_gck_round_rate,
+ .recalc_rate = lan966x_gck_recalc_rate,
+ .determine_rate = lan966x_gck_determine_rate,
+ .set_parent = lan966x_gck_set_parent,
+ .get_parent = lan966x_gck_get_parent,
+};
+
+static struct clk_hw *lan966x_gck_clk_register(struct device *dev, int i)
+{
+ struct lan966x_gck *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return ERR_PTR(-ENOMEM);
+
+ priv->reg = base + (i * 4);
+ priv->hw.init = &init;
+ ret = devm_clk_hw_register(dev, &priv->hw);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return &priv->hw;
+};
+
+static int lan966x_clk_probe(struct platform_device *pdev)
+{
+ struct clk_hw_onecell_data *hw_data;
+ struct device *dev = &pdev->dev;
+ const char *parent_names[3];
+ int i, ret;
+
+ hw_data = devm_kzalloc(dev, sizeof(*hw_data), GFP_KERNEL);
+ if (!hw_data)
+ return -ENOMEM;
+
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ init.ops = &lan966x_gck_ops;
+ init.num_parents = 3;
+
+ for (i = 0; i < init.num_parents; ++i) {
+ parent_names[i] = of_clk_get_parent_name(pdev->dev.of_node, i);
+ if (!parent_names[i])
+ return -EINVAL;
+ }
+
+ init.parent_names = parent_names;
+ hw_data->num = N_CLOCKS;
+
+ for (i = 0; i < N_CLOCKS; i++) {
+ init.name = clk_names[i];
+ hw_data->hws[i] = lan966x_gck_clk_register(dev, i);
+ if (IS_ERR(hw_data->hws[i])) {
+ dev_err(dev, "failed to register %s clock\n",
+ init.name);
+ return ret;
+ }
+ }
+
+ return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, hw_data);
+}
+
+static const struct of_device_id lan966x_clk_dt_ids[] = {
+ { .compatible = "microchip,lan966x-gck", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, lan966x_clk_dt_ids);
+
+static struct platform_driver lan966x_clk_driver = {
+ .probe = lan966x_clk_probe,
+ .driver = {
+ .name = "lan966x-clk",
+ .of_match_table = lan966x_clk_dt_ids,
+ },
+};
+builtin_platform_driver(lan966x_clk_driver);
+
+MODULE_AUTHOR("Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>");
+MODULE_DESCRIPTION("LAN966X clock driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2 3/3] dt-bindings: clock: lan966x: Add LAN966X Clock Controller
2021-09-08 11:48 [PATCH v2 0/3] Add driver for lan966x Generic Clock Controlle Kavyasree Kotagiri
2021-09-08 11:48 ` [PATCH v2 1/3] dt-bindings: clock: lan966x: Add binding includes for lan966x SoC clock IDs Kavyasree Kotagiri
2021-09-08 11:48 ` [PATCH v2 2/3] clk: lan966x: Add lan966x SoC clock driver Kavyasree Kotagiri
@ 2021-09-08 11:48 ` Kavyasree Kotagiri
2021-09-08 13:53 ` Rob Herring
2 siblings, 1 reply; 5+ messages in thread
From: Kavyasree Kotagiri @ 2021-09-08 11:48 UTC (permalink / raw)
To: robh+dt, mturquette, sboyd
Cc: linux-kernel, devicetree, linux-clk, UNGLinuxDriver,
Eugen.Hristev, Kavyasree.Kotagiri, Manohar.Puri
This adds the DT bindings documentation for lan966x SoC
generic clock controller.
Signed-off-by: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
---
v1 -> v2:
- Updated example provided for clk controller DT node.
.../bindings/clock/microchip,lan966x-gck.yaml | 64 +++++++++++++++++++
1 file changed, 64 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/microchip,lan966x-gck.yaml
diff --git a/Documentation/devicetree/bindings/clock/microchip,lan966x-gck.yaml b/Documentation/devicetree/bindings/clock/microchip,lan966x-gck.yaml
new file mode 100644
index 000000000000..cb8c1f5002f8
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/microchip,lan966x-gck.yaml
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/microchip,lan966x-gck.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip LAN966X Generic Clock Controller
+
+maintainers:
+ - Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
+
+description: |
+ The LAN966X Generic clock controller contains 3 PLLs - cpu_clk,
+ ddr_clk and sys_clk. This clock controller generates and supplies
+ clock to various peripherals within the SoC.
+
+properties:
+ compatible:
+ const: microchip,lan966x-gck
+
+ reg:
+ maxItems: 1
+
+ clocks:
+ maxItems: 1
+
+ '#clock-cells':
+ const: 1
+
+required:
+ - compatible
+ - reg
+ - clocks
+ - '#clock-cells'
+
+additionalProperties: false
+
+examples:
+ - |
+ cpu_clk: cpu_clk {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <600000000>;
+ };
+
+ ddr_clk: ddr_clk {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <300000000>;
+ };
+
+ sys_clk: sys_clk {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <162500000>;
+ };
+
+ clks: clock-controller@e00c00a8 {
+ compatible = "microchip,lan966x-gck";
+ #clock-cells = <1>;
+ clocks = <&cpu_clk>, <&ddr_clk>, <&sys_clk>;
+ reg = <0xe00c00a8 0x38>;
+ };
+...
--
2.17.1
^ permalink raw reply [flat|nested] 5+ messages in thread