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authorJose Abreu <Jose.Abreu@synopsys.com>2016-05-02 10:39:05 +0100
committerStephen Boyd <sboyd@codeaurora.org>2016-05-06 10:35:04 -0700
commit923587aafc2c41ed516d39651d5750ea402cfc06 (patch)
tree533a48d7ef3592984d117786b7de2900a1abf554 /drivers/clk/axs10x
parentc47265ad64fa793657ce7ecf1a8f636c794e9f40 (diff)
clk/axs10x: Add I2S PLL clock driver
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@synopsys.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk/axs10x')
-rw-r--r--drivers/clk/axs10x/Makefile1
-rw-r--r--drivers/clk/axs10x/i2s_pll_clock.c228
2 files changed, 229 insertions, 0 deletions
diff --git a/drivers/clk/axs10x/Makefile b/drivers/clk/axs10x/Makefile
new file mode 100644
index 000000000000..01996b871b06
--- /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 000000000000..411310d29581
--- /dev/null
+++ b/drivers/clk/axs10x/i2s_pll_clock.c
@@ -0,0 +1,228 @@
+/*
+ * 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/platform_device.h>
+#include <linux/module.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+/* PLL registers addresses */
+#define PLL_IDIV_REG 0x0
+#define PLL_FBDIV_REG 0x4
+#define PLL_ODIV0_REG 0x8
+#define PLL_ODIV1_REG 0xC
+
+struct i2s_pll_cfg {
+ unsigned int rate;
+ unsigned int idiv;
+ unsigned int fbdiv;
+ unsigned int odiv0;
+ unsigned int odiv1;
+};
+
+static const 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 const 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 {
+ void __iomem *base;
+ struct clk_hw hw;
+ struct device *dev;
+};
+
+static inline void i2s_pll_write(struct i2s_pll_clk *clk, unsigned int reg,
+ unsigned int val)
+{
+ writel_relaxed(val, clk->base + reg);
+}
+
+static inline unsigned int i2s_pll_read(struct i2s_pll_clk *clk,
+ unsigned int reg)
+{
+ return readl_relaxed(clk->base + reg);
+}
+
+static inline struct i2s_pll_clk *to_i2s_pll_clk(struct clk_hw *hw)
+{
+ return container_of(hw, struct i2s_pll_clk, hw);
+}
+
+static inline unsigned int i2s_pll_get_value(unsigned int val)
+{
+ return (val & 0x3F) + ((val >> 6) & 0x3F);
+}
+
+static const struct i2s_pll_cfg *i2s_pll_get_cfg(unsigned long prate)
+{
+ switch (prate) {
+ case 27000000:
+ return i2s_pll_cfg_27m;
+ case 28224000:
+ return i2s_pll_cfg_28m;
+ default:
+ return NULL;
+ }
+}
+
+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(i2s_pll_read(clk, PLL_IDIV_REG));
+ fbdiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_FBDIV_REG));
+ odiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_ODIV0_REG));
+
+ return ((parent_rate / idiv) * fbdiv) / odiv;
+}
+
+static long i2s_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
+ const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(*prate);
+ int i;
+
+ if (!pll_cfg) {
+ dev_err(clk->dev, "invalid parent rate=%ld\n", *prate);
+ return -EINVAL;
+ }
+
+ for (i = 0; pll_cfg[i].rate != 0; i++)
+ if (pll_cfg[i].rate == rate)
+ return rate;
+
+ return -EINVAL;
+}
+
+static int i2s_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
+ const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(parent_rate);
+ int i;
+
+ if (!pll_cfg) {
+ dev_err(clk->dev, "invalid parent rate=%ld\n", parent_rate);
+ return -EINVAL;
+ }
+
+ for (i = 0; pll_cfg[i].rate != 0; i++) {
+ if (pll_cfg[i].rate == rate) {
+ i2s_pll_write(clk, PLL_IDIV_REG, pll_cfg[i].idiv);
+ i2s_pll_write(clk, PLL_FBDIV_REG, pll_cfg[i].fbdiv);
+ i2s_pll_write(clk, PLL_ODIV0_REG, pll_cfg[i].odiv0);
+ i2s_pll_write(clk, PLL_ODIV1_REG, pll_cfg[i].odiv1);
+ return 0;
+ }
+ }
+
+ dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", 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 int i2s_pll_clk_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ const char *clk_name;
+ const char *parent_name;
+ struct clk *clk;
+ struct i2s_pll_clk *pll_clk;
+ struct clk_init_data init;
+ struct resource *mem;
+
+ pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
+ if (!pll_clk)
+ return -ENOMEM;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pll_clk->base = devm_ioremap_resource(dev, mem);
+ if (IS_ERR(pll_clk->base))
+ return PTR_ERR(pll_clk->base);
+
+ clk_name = node->name;
+ init.name = clk_name;
+ init.ops = &i2s_pll_ops;
+ parent_name = of_clk_get_parent_name(node, 0);
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+ pll_clk->hw.init = &init;
+ pll_clk->dev = dev;
+
+ clk = devm_clk_register(dev, &pll_clk->hw);
+ if (IS_ERR(clk)) {
+ dev_err(dev, "failed to register %s clock (%ld)\n",
+ clk_name, PTR_ERR(clk));
+ return PTR_ERR(clk);
+ }
+
+ return of_clk_add_provider(node, of_clk_src_simple_get, clk);
+}
+
+static int i2s_pll_clk_remove(struct platform_device *pdev)
+{
+ of_clk_del_provider(pdev->dev.of_node);
+ return 0;
+}
+
+static const struct of_device_id i2s_pll_clk_id[] = {
+ { .compatible = "snps,axs10x-i2s-pll-clock", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, i2s_pll_clk_id);
+
+static struct platform_driver i2s_pll_clk_driver = {
+ .driver = {
+ .name = "axs10x-i2s-pll-clock",
+ .of_match_table = i2s_pll_clk_id,
+ },
+ .probe = i2s_pll_clk_probe,
+ .remove = i2s_pll_clk_remove,
+};
+module_platform_driver(i2s_pll_clk_driver);
+
+MODULE_AUTHOR("Jose Abreu <joabreu@synopsys.com>");
+MODULE_DESCRIPTION("Synopsys AXS10X SDP I2S PLL Clock Driver");
+MODULE_LICENSE("GPL v2");