[PATCH RFC 06/46] imx-drm: ipu-v3: more clocking fixes

Russell King
2014-01-02T21:26:16Z

There's no point in using the clk API for this; we end up having to
violate the layering this provides.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
drivers/staging/imx-drm/ipu-v3/ipu-di.c | 328 ++++++++++---------------------
1 files changed, 105 insertions(+), 223 deletions(-)

diff --git a/drivers/staging/imx-drm/ipu-v3/ipu-di.c b/drivers/staging/imx-drm/ipu-v3/ipu-di.c
index d766e18bfca0..82a9ebad697c 100644
--- a/drivers/staging/imx-drm/ipu-v3/ipu-di.c
+++ b/drivers/staging/imx-drm/ipu-v3/ipu-di.c
@@ -19,9 +19,6 @@
#include <linux/io.h>
#include <linux/err.h>
#include <linux/platform_device.h>
-#include <linux/clk.h>
-#include <linux/clk-provider.h>
-#include <linux/clkdev.h>

#include "imx-ipu-v3.h"
#include "ipu-prv.h"
@@ -33,10 +30,7 @@ struct ipu_di {
struct clk *clk_di; /* display input clock */
struct clk *clk_ipu; /* IPU bus clock */
struct clk *clk_di_pixel; /* resulting pixel clock */
- struct clk_hw clk_hw_out;
- char *clk_name;
bool inuse;
- unsigned long clkflags;
struct ipu_soc *ipu;
};

@@ -141,130 +135,6 @@ static inline void ipu_di_write(struct ipu_di *di, u32 value, unsigned offset)
writel(value, di->base + offset);
}

-static int ipu_di_clk_calc_div(unsigned long inrate, unsigned long outrate)
-{
- u64 tmp = inrate;
- int div;
-
- tmp *= 16;
-
- do_div(tmp, outrate);
-
- div = tmp;
-
- if (div < 0x10)
- div = 0x10;
-
-#ifdef WTF_IS_THIS
- /*
- * Freescale has this in their Kernel. It is neither clear what
- * it does nor why it does it
- */
- if (div & 0x10)
- div &= ~0x7;
- else {
- /* Round up divider if it gets us closer to desired pix clk */
- if ((div & 0xC) == 0xC) {
- div += 0x10;
- div &= ~0xF;
- }
- }
-#endif
- return div;
-}
-
-static unsigned long clk_di_recalc_rate(struct clk_hw *hw,
- unsigned long parent_rate)
-{
- struct ipu_di *di = container_of(hw, struct ipu_di, clk_hw_out);
- unsigned long outrate;
- u32 div = ipu_di_read(di, DI_BS_CLKGEN0);
-
- if (div < 0x10)
- div = 0x10;
-
- outrate = (parent_rate / div) * 16;
-
- return outrate;
-}
-
-static long clk_di_round_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long *prate)
-{
- struct ipu_di *di = container_of(hw, struct ipu_di, clk_hw_out);
- unsigned long outrate;
- int div;
- u32 val;
-
- div = ipu_di_clk_calc_div(*prate, rate);
-
- outrate = (*prate / div) * 16;
-
- val = ipu_di_read(di, DI_GENERAL);
-
- if (!(val & DI_GEN_DI_CLK_EXT) && outrate > *prate / 2)
- outrate = *prate / 2;
-
- dev_dbg(di->ipu->dev,
- "%s: inrate: %ld div: 0x%08x outrate: %ld wanted: %ld\n",
- __func__, *prate, div, outrate, rate);
-
- return outrate;
-}
-
-static int clk_di_set_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long parent_rate)
-{
- struct ipu_di *di = container_of(hw, struct ipu_di, clk_hw_out);
- int div;
- u32 clkgen0;
-
- clkgen0 = ipu_di_read(di, DI_BS_CLKGEN0) & ~0xfff;
-
- div = ipu_di_clk_calc_div(parent_rate, rate);
-
- ipu_di_write(di, clkgen0 | div, DI_BS_CLKGEN0);
-
- dev_dbg(di->ipu->dev, "%s: inrate: %ld desired: %ld div: 0x%08x\n",
- __func__, parent_rate, rate, div);
- return 0;
-}
-
-static u8 clk_di_get_parent(struct clk_hw *hw)
-{
- struct ipu_di *di = container_of(hw, struct ipu_di, clk_hw_out);
- u32 val;
-
- val = ipu_di_read(di, DI_GENERAL);
-
- return val & DI_GEN_DI_CLK_EXT ? 1 : 0;
-}
-
-static int clk_di_set_parent(struct clk_hw *hw, u8 index)
-{
- struct ipu_di *di = container_of(hw, struct ipu_di, clk_hw_out);
- u32 val;
-
- val = ipu_di_read(di, DI_GENERAL);
-
- if (index)
- val |= DI_GEN_DI_CLK_EXT;
- else
- val &= ~DI_GEN_DI_CLK_EXT;
-
- ipu_di_write(di, val, DI_GENERAL);
-
- return 0;
-}
-
-static struct clk_ops clk_di_ops = {
- .round_rate = clk_di_round_rate,
- .set_rate = clk_di_set_rate,
- .recalc_rate = clk_di_recalc_rate,
- .set_parent = clk_di_set_parent,
- .get_parent = clk_di_get_parent,
-};
-
static void ipu_di_data_wave_config(struct ipu_di *di,
int wave_gen,
int access_size, int component_size)
@@ -528,42 +398,58 @@ static void ipu_di_sync_config_noninterlaced(struct ipu_di *di,
ipu_di_sync_config(di, cfg_vga, 0, ARRAY_SIZE(cfg_vga));
}

-int ipu_di_init_sync_panel(struct ipu_di *di, struct ipu_di_signal_cfg *sig)
+static void ipu_di_config_clock(struct ipu_di *di,
+ const struct ipu_di_signal_cfg *sig)
{
- u32 reg;
- u32 di_gen, vsync_cnt;
- u32 div;
- u32 h_total, v_total;
- int ret;
- unsigned long round;
- struct clk *parent;
+ struct clk *clk;
+ unsigned clkgen0;
+ uint32_t val;

- dev_dbg(di->ipu->dev, "disp %d: panel size = %d x %d\n",
- di->id, sig->width, sig->height);
+ if (sig->clkflags & IPU_DI_CLKMODE_EXT) {
+ /*
+ * CLKMODE_EXT means we must use the DI clock: this is
+ * needed for things like LVDS which needs to feed the
+ * DI and LDB with the same pixel clock.
+ */
+ clk = di->clk_di;
+
+ if (sig->clkflags & IPU_DI_CLKMODE_SYNC) {
+ /*
+ * CLKMODE_SYNC means that we want the DI to be
+ * clocked at the same rate as the parent clock.
+ * This is needed (eg) for LDB which needs to be
+ * fed with the same pixel clock. We assume that
+ * the LDB clock has already been set correctly.
+ */
+ clkgen0 = 1 << 4;
+ } else {
+ /*
+ * We can use the divider. We should really have
+ * a flag here indicating whether the bridge can
+ * cope with a fractional divider or not. For the
+ * time being, let's go for simplicitly and
+ * reliability.
+ */
+ unsigned long in_rate;
+ unsigned div;

- if ((sig->v_sync_width == 0) || (sig->h_sync_width == 0))
- return -EINVAL;
+ clk_set_rate(clk, sig->pixelclock);

- dev_dbg(di->ipu->dev, "Clocks: IPU %luHz DI %luHz Needed %luHz\n",
- clk_get_rate(di->clk_ipu),
- clk_get_rate(di->clk_di),
- sig->pixelclock);
+ in_rate = clk_get_rate(clk);
+ div = (in_rate + sig->pixelclock / 2) / sig->pixelclock;
+ if (div == 0)
+ div = 1;

- /*
- * CLKMODE_EXT means we must use the DI clock: this is needed
- * for things like LVDS which needs to feed the DI and LDB with
- * the same pixel clock.
- *
- * For other interfaces, we can arbitarily select between the DI
- * specific clock and the internal IPU clock. See DI_GENERAL
- * bit 20. We select the IPU clock if it can give us a clock
- * rate within 1% of the requested frequency, otherwise we use
- * the DI clock.
- */
- round = sig->pixelclock;
- if (sig->clkflags & IPU_DI_CLKMODE_EXT) {
- parent = di->clk_di;
+ clkgen0 = div << 4;
+ }
} else {
+ /*
+ * For other interfaces, we can arbitarily select between
+ * the DI specific clock and the internal IPU clock. See
+ * DI_GENERAL bit 20. We select the IPU clock if it can
+ * give us a clock rate within 1% of the requested frequency,
+ * otherwise we use the DI clock.
+ */
unsigned long rate, clkrate;
unsigned div, error;

@@ -578,54 +464,80 @@ int ipu_di_init_sync_panel(struct ipu_di *di, struct ipu_di_signal_cfg *sig)

/* Allow a 1% error */
if (error < 1010 && error >= 990) {
- parent = di->clk_ipu;
+ clk = di->clk_ipu;
+
+ clkgen0 = div << 4;
} else {
- parent = di->clk_di;
+ unsigned long in_rate;
+ unsigned div;
+
+ clk = di->clk_di;

- ret = clk_set_rate(parent, sig->pixelclock);
- if (ret)
- dev_err(di->ipu->dev, "Setting of DI clock failed: %d\n", ret);
+ clk_set_rate(clk, sig->pixelclock);

- /* Use the integer divisor rate - avoid fractional dividers */
- round = rate;
+ in_rate = clk_get_rate(clk);
+ div = (in_rate + sig->pixelclock / 2) / sig->pixelclock;
+ if (div == 0)
+ div = 1;
+
+ clkgen0 = div << 4;
}
}

- ret = clk_set_parent(di->clk_di_pixel, parent);
- if (ret) {
- dev_err(di->ipu->dev,
- "setting pixel clock to parent %s failed with %d\n",
- __clk_get_name(parent), ret);
- return ret;
- }
+ di->clk_di_pixel = clk;
+
+ /* Set the divider */
+ ipu_di_write(di, clkgen0, DI_BS_CLKGEN0);

/*
- * CLKMODE_SYNC means that we want the DI to be clocked at the
- * same rate as the parent clock. This is needed (eg) for LDB
- * which needs to be fed with the same pixel clock.
- *
- * Note: clk_set_rate(clk, clk_round_rate(clk, rate)) is the
- * same as clk_set_rate(clk, rate);
+ * Set the high/low periods. Bits 24:16 give us the falling edge,
+ * and bits 8:0 give the rising edge. LSB is fraction, and is
+ * based on the divider above. We want a 50% duty cycle, so set
+ * the falling edge to be half the divider.
*/
- if (sig->clkflags & IPU_DI_CLKMODE_SYNC)
- round = clk_get_rate(parent);
+ ipu_di_write(di, (clkgen0 >> 4) << 16, DI_BS_CLKGEN1);

- ret = clk_set_rate(di->clk_di_pixel, round);
+ /* Finally select the input clock */
+ val = ipu_di_read(di, DI_GENERAL) & ~DI_GEN_DI_CLK_EXT;
+ if (clk == di->clk_di)
+ val |= DI_GEN_DI_CLK_EXT;
+ ipu_di_write(di, val, DI_GENERAL);

- dev_dbg(di->ipu->dev, "Want %luHz IPU %luHz DI %luHz using %s, got %luHz\n",
+ dev_dbg(di->ipu->dev, "Want %luHz IPU %luHz DI %luHz using %s, %luHz\n",
sig->pixelclock,
clk_get_rate(di->clk_ipu),
clk_get_rate(di->clk_di),
- parent == di->clk_di ? "DI" : "IPU",
- clk_get_rate(di->clk_di_pixel));
+ clk == di->clk_di ? "DI" : "IPU",
+ clk_get_rate(di->clk_di_pixel) / (clkgen0 >> 4));
+}
+
+int ipu_di_init_sync_panel(struct ipu_di *di, struct ipu_di_signal_cfg *sig)
+{
+ u32 reg;
+ u32 di_gen, vsync_cnt;
+ u32 div;
+ u32 h_total, v_total;
+
+ dev_dbg(di->ipu->dev, "disp %d: panel size = %d x %d\n",
+ di->id, sig->width, sig->height);
+
+ if ((sig->v_sync_width == 0) || (sig->h_sync_width == 0))
+ return -EINVAL;

h_total = sig->width + sig->h_sync_width + sig->h_start_width +
sig->h_end_width;
v_total = sig->height + sig->v_sync_width + sig->v_start_width +
sig->v_end_width;

+ dev_dbg(di->ipu->dev, "Clocks: IPU %luHz DI %luHz Needed %luHz\n",
+ clk_get_rate(di->clk_ipu),
+ clk_get_rate(di->clk_di),
+ sig->pixelclock);
+
mutex_lock(&di_mutex);

+ ipu_di_config_clock(di, sig);
+
div = ipu_di_read(di, DI_BS_CLKGEN0) & 0xfff;
div = div / 16; /* Now divider is integer portion */

@@ -709,7 +621,11 @@ EXPORT_SYMBOL_GPL(ipu_di_init_sync_panel);

int ipu_di_enable(struct ipu_di *di)
{
- int ret = clk_prepare_enable(di->clk_di_pixel);
+ int ret;
+
+ WARN_ON(IS_ERR(di->clk_di_pixel));
+
+ ret = clk_prepare_enable(di->clk_di_pixel);
if (ret)
return ret;

@@ -721,6 +637,8 @@ EXPORT_SYMBOL_GPL(ipu_di_enable);

int ipu_di_disable(struct ipu_di *di)
{
+ WARN_ON(IS_ERR(di->clk_di_pixel));
+
ipu_module_disable(di->ipu, di->module);

clk_disable_unprepare(di->clk_di_pixel);
@@ -776,13 +694,6 @@ int ipu_di_init(struct ipu_soc *ipu, struct device *dev, int id,
u32 module, struct clk *clk_ipu)
{
struct ipu_di *di;
- int ret;
- const char *di_parent[2];
- struct clk_init_data init = {
- .ops = &clk_di_ops,
- .num_parents = 2,
- .flags = 0,
- };

if (id > 1)
return -ENODEV;
@@ -804,45 +715,16 @@ int ipu_di_init(struct ipu_soc *ipu, struct device *dev, int id,
if (!di->base)
return -ENOMEM;

- di_parent[0] = __clk_get_name(di->clk_ipu);
- di_parent[1] = __clk_get_name(di->clk_di);
-
ipu_di_write(di, 0x10, DI_BS_CLKGEN0);

- init.parent_names = (const char **)&di_parent;
- di->clk_name = kasprintf(GFP_KERNEL, "%s_di%d_pixel",
- dev_name(dev), id);
- if (!di->clk_name)
- return -ENOMEM;
-
- init.name = di->clk_name;
-
- di->clk_hw_out.init = &init;
- di->clk_di_pixel = clk_register(dev, &di->clk_hw_out);
-
- if (IS_ERR(di->clk_di_pixel)) {
- ret = PTR_ERR(di->clk_di_pixel);
- goto failed_clk_register;
- }
-
dev_dbg(dev, "DI%d base: 0x%08lx remapped to %p\n",
id, base, di->base);
di->inuse = false;
di->ipu = ipu;

return 0;
-
-failed_clk_register:
-
- kfree(di->clk_name);
-
- return ret;
}

void ipu_di_exit(struct ipu_soc *ipu, int id)
{
- struct ipu_di *di = ipu->di_priv[id];
-
- clk_unregister(di->clk_di_pixel);
- kfree(di->clk_name);
}
--
1.7.4.4