[PATCH 14/21] ARM: tegra: clock: Refcount periph clock enables

Colin Cross
2011-02-13T09:43:33Z

Some peripheral clocks share enable bits. Refcount the enables so
that calling clk_disable on one clock will not turn off another
clock.

Signed-off-by: Colin Cross <ccross@android.com>
---
arch/arm/mach-tegra/tegra2_clocks.c | 35 +++++++++++++++++++++++++++++------
1 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/arch/arm/mach-tegra/tegra2_clocks.c b/arch/arm/mach-tegra/tegra2_clocks.c
index 6905bd0..2f79128 100644
--- a/arch/arm/mach-tegra/tegra2_clocks.c
+++ b/arch/arm/mach-tegra/tegra2_clocks.c
@@ -154,6 +154,12 @@ static void __iomem *reg_pmc_base = IO_ADDRESS(TEGRA_PMC_BASE);
*/
static DEFINE_SPINLOCK(clock_register_lock);

+/*
+ * Some peripheral clocks share an enable bit, so refcount the enable bits
+ * in registers CLK_ENABLE_L, CLK_ENABLE_H, and CLK_ENABLE_U
+ */
+static int tegra_periph_clk_enable_refcount[3 * 32];
+
#define clk_writel(value, reg) \
__raw_writel(value, (u32)reg_clk_base + (reg))
#define clk_readl(reg) \
@@ -920,8 +926,19 @@ static void tegra2_periph_clk_init(struct clk *c)
static int tegra2_periph_clk_enable(struct clk *c)
{
u32 val;
+ unsigned long flags;
+ int refcount;
pr_debug("%s on clock %s\n", __func__, c->name);

+ spin_lock_irqsave(&clock_register_lock, flags);
+
+ refcount = tegra_periph_clk_enable_refcount[c->u.periph.clk_num]++;
+
+ spin_unlock_irqrestore(&clock_register_lock, flags);
+
+ if (refcount > 1)
+ return 0;
+
clk_writel(PERIPH_CLK_TO_ENB_BIT(c),
CLK_OUT_ENB_SET + PERIPH_CLK_TO_ENB_SET_REG(c));
if (!(c->flags & PERIPH_NO_RESET) && !(c->flags & PERIPH_MANUAL_RESET))
@@ -939,10 +956,20 @@ static int tegra2_periph_clk_enable(struct clk *c)

static void tegra2_periph_clk_disable(struct clk *c)
{
+ unsigned long flags;
+
pr_debug("%s on clock %s\n", __func__, c->name);

- clk_writel(PERIPH_CLK_TO_ENB_BIT(c),
- CLK_OUT_ENB_CLR + PERIPH_CLK_TO_ENB_SET_REG(c));
+ spin_lock_irqsave(&clock_register_lock, flags);
+
+ if (c->refcnt)
+ tegra_periph_clk_enable_refcount[c->u.periph.clk_num]--;
+
+ if (tegra_periph_clk_enable_refcount[c->u.periph.clk_num] == 0)
+ clk_writel(PERIPH_CLK_TO_ENB_BIT(c),
+ CLK_OUT_ENB_CLR + PERIPH_CLK_TO_ENB_SET_REG(c));
+
+ spin_unlock_irqrestore(&clock_register_lock, flags);
}

static void tegra2_periph_clk_reset(struct clk *c, bool assert)
@@ -1940,7 +1967,6 @@ struct clk tegra_list_clks[] = {
PERIPH_CLK("timer", "timer", NULL, 5, 0, 26000000, mux_clk_m, 0),
PERIPH_CLK("i2s1", "i2s.0", NULL, 11, 0x100, 26000000, mux_pllaout0_audio2x_pllp_clkm, MUX | DIV_U71),
PERIPH_CLK("i2s2", "i2s.1", NULL, 18, 0x104, 26000000, mux_pllaout0_audio2x_pllp_clkm, MUX | DIV_U71),
- /* FIXME: spdif has 2 clocks but 1 enable */
PERIPH_CLK("spdif_out", "spdif_out", NULL, 10, 0x108, 100000000, mux_pllaout0_audio2x_pllp_clkm, MUX | DIV_U71),
PERIPH_CLK("spdif_in", "spdif_in", NULL, 10, 0x10c, 100000000, mux_pllp_pllc_pllm, MUX | DIV_U71),
PERIPH_CLK("pwm", "pwm", NULL, 17, 0x110, 432000000, mux_pllp_pllc_audio_clkm_clk32, MUX | DIV_U71),
@@ -1953,7 +1979,6 @@ struct clk tegra_list_clks[] = {
PERIPH_CLK("sbc4", "spi_tegra.3", NULL, 68, 0x1b4, 160000000, mux_pllp_pllc_pllm_clkm, MUX | DIV_U71),
PERIPH_CLK("ide", "ide", NULL, 25, 0x144, 100000000, mux_pllp_pllc_pllm_clkm, MUX | DIV_U71), /* requires min voltage */
PERIPH_CLK("ndflash", "tegra_nand", NULL, 13, 0x160, 164000000, mux_pllp_pllc_pllm_clkm, MUX | DIV_U71), /* scales with voltage */
- /* FIXME: vfir shares an enable with uartb */
PERIPH_CLK("vfir", "vfir", NULL, 7, 0x168, 72000000, mux_pllp_pllc_pllm_clkm, MUX | DIV_U71),
PERIPH_CLK("sdmmc1", "sdhci-tegra.0", NULL, 14, 0x150, 52000000, mux_pllp_pllc_pllm_clkm, MUX | DIV_U71), /* scales with voltage */
PERIPH_CLK("sdmmc2", "sdhci-tegra.1", NULL, 9, 0x154, 52000000, mux_pllp_pllc_pllm_clkm, MUX | DIV_U71), /* scales with voltage */
@@ -1981,13 +2006,11 @@ struct clk tegra_list_clks[] = {
PERIPH_CLK("uarte", "uart.4", NULL, 66, 0x1c4, 600000000, mux_pllp_pllc_pllm_clkm, MUX),
PERIPH_CLK("3d", "3d", NULL, 24, 0x158, 300000000, mux_pllm_pllc_pllp_plla, MUX | DIV_U71 | PERIPH_MANUAL_RESET), /* scales with voltage and process_id */
PERIPH_CLK("2d", "2d", NULL, 21, 0x15c, 300000000, mux_pllm_pllc_pllp_plla, MUX | DIV_U71), /* scales with voltage and process_id */
- /* FIXME: vi and vi_sensor share an enable */
PERIPH_CLK("vi", "tegra_camera", "vi", 20, 0x148, 150000000, mux_pllm_pllc_pllp_plla, MUX | DIV_U71), /* scales with voltage and process_id */
PERIPH_CLK("vi_sensor", "tegra_camera", "vi_sensor", 20, 0x1a8, 150000000, mux_pllm_pllc_pllp_plla, MUX | DIV_U71 | PERIPH_NO_RESET), /* scales with voltage and process_id */
PERIPH_CLK("epp", "epp", NULL, 19, 0x16c, 300000000, mux_pllm_pllc_pllp_plla, MUX | DIV_U71), /* scales with voltage and process_id */
PERIPH_CLK("mpe", "mpe", NULL, 60, 0x170, 250000000, mux_pllm_pllc_pllp_plla, MUX | DIV_U71), /* scales with voltage and process_id */
PERIPH_CLK("host1x", "host1x", NULL, 28, 0x180, 166000000, mux_pllm_pllc_pllp_plla, MUX | DIV_U71), /* scales with voltage and process_id */
- /* FIXME: cve and tvo share an enable */
PERIPH_CLK("cve", "cve", NULL, 49, 0x140, 250000000, mux_pllp_plld_pllc_clkm, MUX | DIV_U71), /* requires min voltage */
PERIPH_CLK("tvo", "tvo", NULL, 49, 0x188, 250000000, mux_pllp_plld_pllc_clkm, MUX | DIV_U71), /* requires min voltage */
PERIPH_CLK("hdmi", "hdmi", NULL, 51, 0x18c, 600000000, mux_pllp_plld_pllc_clkm, MUX | DIV_U71), /* requires min voltage */
--
1.7.3.1