[PATCH 17/21] ARM: tegra: clocks: Add emc scaling

Colin Cross
2011-02-13T09:43:57Z

arch/arm/mach-tegra/tegra2_clocks.c | 62 ++++++++++++++++++++++++++++++++++-
1 files changed, 61 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mach-tegra/tegra2_clocks.c b/arch/arm/mach-tegra/tegra2_clocks.c
index 96b2490..f4173ec 100644
--- a/arch/arm/mach-tegra/tegra2_clocks.c
+++ b/arch/arm/mach-tegra/tegra2_clocks.c
@@ -31,6 +31,7 @@

#include "clock.h"
#include "fuse.h"
+#include "tegra2_emc.h"

#define RST_DEVICES 0x004
#define RST_DEVICES_SET 0x300
@@ -1078,6 +1079,53 @@ static struct clk_ops tegra_periph_clk_ops = {
.reset = &tegra2_periph_clk_reset,
};

+/* External memory controller clock ops */
+static void tegra2_emc_clk_init(struct clk *c)
+{
+ tegra2_periph_clk_init(c);
+ c->max_rate = clk_get_rate_locked(c);
+}
+
+static long tegra2_emc_clk_round_rate(struct clk *c, unsigned long rate)
+{
+ long new_rate = rate;
+
+ new_rate = tegra_emc_round_rate(new_rate);
+ if (new_rate < 0)
+ return c->max_rate;
+
+ BUG_ON(new_rate != tegra2_periph_clk_round_rate(c, new_rate));
+
+ return new_rate;
+}
+
+static int tegra2_emc_clk_set_rate(struct clk *c, unsigned long rate)
+{
+ int ret;
+ /* The Tegra2 memory controller has an interlock with the clock
+ * block that allows memory shadowed registers to be updated,
+ * and then transfer them to the main registers at the same
+ * time as the clock update without glitches. */
+ ret = tegra_emc_set_rate(rate);
+ if (ret < 0)
+ return ret;
+
+ ret = tegra2_periph_clk_set_rate(c, rate);
+ udelay(1);
+
+ return ret;
+}
+
+static struct clk_ops tegra_emc_clk_ops = {
+ .init = &tegra2_emc_clk_init,
+ .enable = &tegra2_periph_clk_enable,
+ .disable = &tegra2_periph_clk_disable,
+ .set_parent = &tegra2_periph_clk_set_parent,
+ .set_rate = &tegra2_emc_clk_set_rate,
+ .round_rate = &tegra2_emc_clk_round_rate,
+ .reset = &tegra2_periph_clk_reset,
+};
+
/* Clock doubler ops */
static void tegra2_clk_double_init(struct clk *c)
{
@@ -1934,6 +1982,18 @@ static struct clk_mux_sel mux_clk_32k[] = {
{ 0, 0},
};

+static struct clk tegra_clk_emc = {
+ .name = "emc",
+ .ops = &tegra_emc_clk_ops,
+ .reg = 0x19c,
+ .max_rate = 800000000,
+ .inputs = mux_pllm_pllc_pllp_clkm,
+ .flags = MUX | DIV_U71 | PERIPH_EMC_ENB,
+ .u.periph = {
+ .clk_num = 57,
+ },
+};
+
#define PERIPH_CLK(_name, _dev, _con, _clk_num, _reg, _max, _inputs, _flags) \
{ \
.name = _name, \
@@ -2020,7 +2080,6 @@ struct clk tegra_list_clks[] = {
PERIPH_CLK("usbd", "fsl-tegra-udc", NULL, 22, 0, 480000000, mux_clk_m, 0), /* requires min voltage */
PERIPH_CLK("usb2", "tegra-ehci.1", NULL, 58, 0, 480000000, mux_clk_m, 0), /* requires min voltage */
PERIPH_CLK("usb3", "tegra-ehci.2", NULL, 59, 0, 480000000, mux_clk_m, 0), /* requires min voltage */
- PERIPH_CLK("emc", "emc", NULL, 57, 0x19c, 800000000, mux_pllm_pllc_pllp_clkm, MUX | DIV_U71 | PERIPH_EMC_ENB),
PERIPH_CLK("dsi", "dsi", NULL, 48, 0, 500000000, mux_plld, 0), /* scales with voltage */
PERIPH_CLK("csi", "tegra_camera", "csi", 52, 0, 72000000, mux_pllp_out3, 0),
PERIPH_CLK("isp", "tegra_camera", "isp", 23, 0, 150000000, mux_clk_m, 0), /* same frequency as VI */
@@ -2096,6 +2155,7 @@ struct clk *tegra_ptr_clks[] = {
&tegra_dev2_clk,
&tegra_clk_virtual_cpu,
&tegra_clk_blink,
+ &tegra_clk_emc,
};

static void tegra2_init_one_clock(struct clk *c)
--
1.7.3.1