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authorJun Nie <jun.nie@linaro.org>2016-12-16 15:26:47 +0800
committerStephen Boyd <sboyd@codeaurora.org>2017-01-09 16:06:43 -0800
commitedc6da239a1ac7ed1c657b1421c7c714a99db4d9 (patch)
tree1993e20ad437eae400985f3a165db6cc58df0cce /drivers/clk/zte/clk.c
parent699902760538eb37cc53725323b57924d1f0f1ff (diff)
clk: zte: add audio clocks for zx296718
The audio related clock support is missing from the existing zx296718 clock driver. Let's add it, so that the upstream ZX SPDIF driver can work for HDMI audio support. Signed-off-by: Jun Nie <jun.nie@linaro.org> Signed-off-by: Shawn Guo <shawn.guo@linaro.org> [sboyd@codeaurora.org: Staticize some more structures] Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Diffstat (limited to 'drivers/clk/zte/clk.c')
-rw-r--r--drivers/clk/zte/clk.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/drivers/clk/zte/clk.c b/drivers/clk/zte/clk.c
index c4c1251bc1e7..878d879b23ff 100644
--- a/drivers/clk/zte/clk.c
+++ b/drivers/clk/zte/clk.c
@@ -9,6 +9,7 @@
#include <linux/clk-provider.h>
#include <linux/err.h>
+#include <linux/gcd.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/slab.h>
@@ -310,3 +311,129 @@ struct clk *clk_register_zx_audio(const char *name,
return clk;
}
+
+#define CLK_AUDIO_DIV_FRAC BIT(0)
+#define CLK_AUDIO_DIV_INT BIT(1)
+#define CLK_AUDIO_DIV_UNCOMMON BIT(1)
+
+#define CLK_AUDIO_DIV_FRAC_NSHIFT 16
+#define CLK_AUDIO_DIV_INT_FRAC_RE BIT(16)
+#define CLK_AUDIO_DIV_INT_FRAC_MAX (0xffff)
+#define CLK_AUDIO_DIV_INT_FRAC_MIN (0x2)
+#define CLK_AUDIO_DIV_INT_INT_SHIFT 24
+#define CLK_AUDIO_DIV_INT_INT_WIDTH 4
+
+struct zx_clk_audio_div_table {
+ unsigned long rate;
+ unsigned int int_reg;
+ unsigned int frac_reg;
+};
+
+#define to_clk_zx_audio_div(_hw) container_of(_hw, struct clk_zx_audio_divider, hw)
+
+static unsigned long audio_calc_rate(struct clk_zx_audio_divider *audio_div,
+ u32 reg_frac, u32 reg_int,
+ unsigned long parent_rate)
+{
+ unsigned long rate, m, n;
+
+ m = reg_frac & 0xffff;
+ n = (reg_frac >> 16) & 0xffff;
+
+ m = (reg_int & 0xffff) * n + m;
+ rate = (parent_rate * n) / m;
+
+ return rate;
+}
+
+static void audio_calc_reg(struct clk_zx_audio_divider *audio_div,
+ struct zx_clk_audio_div_table *div_table,
+ unsigned long rate, unsigned long parent_rate)
+{
+ unsigned int reg_int, reg_frac;
+ unsigned long m, n, div;
+
+ reg_int = parent_rate / rate;
+
+ if (reg_int > CLK_AUDIO_DIV_INT_FRAC_MAX)
+ reg_int = CLK_AUDIO_DIV_INT_FRAC_MAX;
+ else if (reg_int < CLK_AUDIO_DIV_INT_FRAC_MIN)
+ reg_int = 0;
+ m = parent_rate - rate * reg_int;
+ n = rate;
+
+ div = gcd(m, n);
+ m = m / div;
+ n = n / div;
+
+ if ((m >> 16) || (n >> 16)) {
+ if (m > n) {
+ n = n * 0xffff / m;
+ m = 0xffff;
+ } else {
+ m = m * 0xffff / n;
+ n = 0xffff;
+ }
+ }
+ reg_frac = m | (n << 16);
+
+ div_table->rate = parent_rate * n / (reg_int * n + m);
+ div_table->int_reg = reg_int;
+ div_table->frac_reg = reg_frac;
+}
+
+static unsigned long zx_audio_div_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_zx_audio_divider *zx_audio_div = to_clk_zx_audio_div(hw);
+ u32 reg_frac, reg_int;
+
+ reg_frac = readl_relaxed(zx_audio_div->reg_base);
+ reg_int = readl_relaxed(zx_audio_div->reg_base + 0x4);
+
+ return audio_calc_rate(zx_audio_div, reg_frac, reg_int, parent_rate);
+}
+
+static long zx_audio_div_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clk_zx_audio_divider *zx_audio_div = to_clk_zx_audio_div(hw);
+ struct zx_clk_audio_div_table divt;
+
+ audio_calc_reg(zx_audio_div, &divt, rate, *prate);
+
+ return audio_calc_rate(zx_audio_div, divt.frac_reg, divt.int_reg, *prate);
+}
+
+static int zx_audio_div_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_zx_audio_divider *zx_audio_div = to_clk_zx_audio_div(hw);
+ struct zx_clk_audio_div_table divt;
+ unsigned int val;
+
+ audio_calc_reg(zx_audio_div, &divt, rate, parent_rate);
+ if (divt.rate != rate)
+ pr_debug("the real rate is:%ld", divt.rate);
+
+ writel_relaxed(divt.frac_reg, zx_audio_div->reg_base);
+
+ val = readl_relaxed(zx_audio_div->reg_base + 0x4);
+ val &= ~0xffff;
+ val |= divt.int_reg | CLK_AUDIO_DIV_INT_FRAC_RE;
+ writel_relaxed(val, zx_audio_div->reg_base + 0x4);
+
+ mdelay(1);
+
+ val = readl_relaxed(zx_audio_div->reg_base + 0x4);
+ val &= ~CLK_AUDIO_DIV_INT_FRAC_RE;
+ writel_relaxed(val, zx_audio_div->reg_base + 0x4);
+
+ return 0;
+}
+
+const struct clk_ops zx_audio_div_ops = {
+ .recalc_rate = zx_audio_div_recalc_rate,
+ .round_rate = zx_audio_div_round_rate,
+ .set_rate = zx_audio_div_set_rate,
+};