The ARC SDP I2S clock can be programmed using a
specific PLL.
This patch has the goal of adding a clock driver
that programs this PLL.
At this moment the rate values are hardcoded in
a table but in the future it would be ideal to
use a function which determines the PLL values
given the desired rate.
Signed-off-by: Jose Abreu <joabreu at synopsys.com>
---
Changes v2 -> v3:
* Implemented recalc_rate
Changes v1 -> v2:
* Renamed folder to axs10x (as suggested by Alexey Brodkin)
* Added more supported rates
arch/arc/boot/dts/axs10x_mb.dtsi | 5 ++
drivers/clk/Makefile | 1 +
drivers/clk/axs10x/Makefile | 1 +
drivers/clk/axs10x/i2s_pll_clock.c | 163 +++++++++++++++++++++++++++++++++++++
4 files changed, 170 insertions(+)
create mode 100644 drivers/clk/axs10x/Makefile
create mode 100644 drivers/clk/axs10x/i2s_pll_clock.c
diff --git a/arch/arc/boot/dts/axs10x_mb.dtsi b/arch/arc/boot/dts/axs10x_mb.dtsi
index ab5d570..9c68226 100644
--- a/arch/arc/boot/dts/axs10x_mb.dtsi
+++ b/arch/arc/boot/dts/axs10x_mb.dtsi
@@ -23,6 +23,11 @@
#clock-cells = <0>;
};
+ i2sclk: i2sclk {
+ compatible = "snps,i2s-pll-clock";
+ #clock-cells = <0>;
+ };
+
apbclk: apbclk {
compatible = "fixed-clock";
clock-frequency = <50000000>;
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 46869d6..2ca62dc6 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -84,3 +84,4 @@ obj-$(CONFIG_X86) += x86/
obj-$(CONFIG_ARCH_ZX) += zte/
obj-$(CONFIG_ARCH_ZYNQ) += zynq/
obj-$(CONFIG_H8300) += h8300/
+obj-$(CONFIG_ARC_PLAT_AXS10X) += axs10x/
diff --git a/drivers/clk/axs10x/Makefile b/drivers/clk/axs10x/Makefile
new file mode 100644
index 0000000..01996b8
--- /dev/null
+++ b/drivers/clk/axs10x/Makefile
@@ -0,0 +1 @@
+obj-y += i2s_pll_clock.o
diff --git a/drivers/clk/axs10x/i2s_pll_clock.c b/drivers/clk/axs10x/i2s_pll_clock.c
new file mode 100644
index 0000000..f050e70
--- /dev/null
+++ b/drivers/clk/axs10x/i2s_pll_clock.c
@@ -0,0 +1,163 @@
+/*
+ * Synopsys AXS10X SDP I2S PLL clock driver
+ *
+ * Copyright (C) 2016 Synopsys
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+/* FPGA Version Info */
+#define FPGA_VER_INFO 0xE0011230
+#define FPGA_VER_27M 0x000FBED9
+
+/* PLL registers addresses */
+#define PLL_IDIV_ADDR 0xE00100A0
+#define PLL_FBDIV_ADDR 0xE00100A4
+#define PLL_ODIV0_ADDR 0xE00100A8
+#define PLL_ODIV1_ADDR 0xE00100AC
+
+struct i2s_pll_cfg {
+ unsigned int rate;
+ unsigned int idiv;
+ unsigned int fbdiv;
+ unsigned int odiv0;
+ unsigned int odiv1;
+};
+
+static struct i2s_pll_cfg i2s_pll_cfg_27m[] = {
+ /* 27 Mhz */
+ { 1024000, 0x104, 0x451, 0x10E38, 0x2000 },
+ { 1411200, 0x104, 0x596, 0x10D35, 0x2000 },
+ { 1536000, 0x208, 0xA28, 0x10B2C, 0x2000 },
+ { 2048000, 0x82, 0x451, 0x10E38, 0x2000 },
+ { 2822400, 0x82, 0x596, 0x10D35, 0x2000 },
+ { 3072000, 0x104, 0xA28, 0x10B2C, 0x2000 },
+ { 2116800, 0x82, 0x3CF, 0x10C30, 0x2000 },
+ { 2304000, 0x104, 0x79E, 0x10B2C, 0x2000 },
+ { 0, 0, 0, 0, 0 },
+};
+
+static struct i2s_pll_cfg i2s_pll_cfg_28m[] = {
+ /* 28.224 Mhz */
+ { 1024000, 0x82, 0x105, 0x107DF, 0x2000 },
+ { 1411200, 0x28A, 0x1, 0x10001, 0x2000 },
+ { 1536000, 0xA28, 0x187, 0x10042, 0x2000 },
+ { 2048000, 0x41, 0x105, 0x107DF, 0x2000 },
+ { 2822400, 0x145, 0x1, 0x10001, 0x2000 },
+ { 3072000, 0x514, 0x187, 0x10042, 0x2000 },
+ { 2116800, 0x514, 0x42, 0x10001, 0x2000 },
+ { 2304000, 0x619, 0x82, 0x10001, 0x2000 },
+ { 0, 0, 0, 0, 0 },
+};
+
+struct i2s_pll_clk {
+ struct clk_hw hw;
+ unsigned long ref_clk;
+ struct i2s_pll_cfg *pll_cfg;
+};
+
+static inline struct i2s_pll_clk *to_i2s_pll_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct i2s_pll_clk, hw);
+}
+
+static unsigned int i2s_pll_get_value(unsigned int val)
+{
+ return ((val & 0x3F) + ((val >> 6) & 0x3F));
+}
+
+static unsigned long i2s_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
+ unsigned int idiv, fbdiv, odiv;
+
+ idiv = i2s_pll_get_value(readl((void *)PLL_IDIV_ADDR));
+ fbdiv = i2s_pll_get_value(readl((void *)PLL_FBDIV_ADDR));
+ odiv = i2s_pll_get_value(readl((void *)PLL_ODIV0_ADDR));
+
+ return (((clk->ref_clk / idiv ) * fbdiv) / odiv);
+}
+
+static long i2s_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ /* TODO: Round rate to nearest valid rate */
+ return rate;
+}
+
+static int i2s_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct i2s_pll_cfg *pll_cfg = to_i2s_pll_clk(hw)->pll_cfg;
+ int i;
+
+ for (i = 0; pll_cfg[i].rate != 0; i++) {
+ if (pll_cfg[i].rate == rate) {
+ writel(pll_cfg[i].idiv, (void *)PLL_IDIV_ADDR);
+ writel(pll_cfg[i].fbdiv, (void *)PLL_FBDIV_ADDR);
+ writel(pll_cfg[i].odiv0, (void *)PLL_ODIV0_ADDR);
+ writel(pll_cfg[i].odiv1, (void *)PLL_ODIV1_ADDR);
+ return 0;
+ }
+ }
+
+ pr_err("%s: invalid rate=%ld, parent_rate=%ld\n", __func__,
+ rate, parent_rate);
+ return -EINVAL;
+}
+
+static const struct clk_ops i2s_pll_ops = {
+ .recalc_rate = i2s_pll_recalc_rate,
+ .round_rate = i2s_pll_round_rate,
+ .set_rate = i2s_pll_set_rate,
+};
+
+static void __init i2s_pll_clk_setup(struct device_node *node)
+{
+ const char *clk_name = node->name;
+ struct clk *clk;
+ struct i2s_pll_clk *pll_clk;
+ struct clk_init_data init;
+
+ pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
+ if (!pll_clk)
+ return;
+
+ init.name = clk_name;
+ init.ops = &i2s_pll_ops;
+ init.flags = CLK_IS_BASIC;
+ init.num_parents = 0;
+ pll_clk->hw.init = &init;
+
+ clk = clk_register(NULL, &pll_clk->hw);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register %s div clock (%ld)\n",
+ __func__, clk_name, PTR_ERR(clk));
+ goto free_clock;
+ }
+
+ if (readl((void *)FPGA_VER_INFO) <= FPGA_VER_27M) {
+ pll_clk->ref_clk = 27000000;
+ pll_clk->pll_cfg = i2s_pll_cfg_27m;
+ } else {
+ pll_clk->ref_clk = 28224000;
+ pll_clk->pll_cfg = i2s_pll_cfg_28m;
+ }
+
+ of_clk_add_provider(node, of_clk_src_simple_get, clk);
+ return;
+
+free_clock:
+ kfree(pll_clk);
+}
+
+CLK_OF_DECLARE(i2s_pll_clk, "snps,i2s-pll-clock", i2s_pll_clk_setup);
+
--
1.9.1
