[media] omap3isp: Use the common clock framework

Expose the two ISP external clocks XCLKA and XCLKB as common clocks for
subdev drivers.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 219 insertions, 80 deletions

diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c
index 6e5ad8ec0a22..1d7dbd5c0fba 100644
--- a/drivers/media/platform/omap3isp/isp.c
+++ b/drivers/media/platform/omap3isp/isp.c
@@ -55,6 +55,7 @@
 #include <asm/cacheflush.h>
 
 #include <linux/clk.h>
+#include <linux/clkdev.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
@@ -148,6 +149,201 @@ void omap3isp_flush(struct isp_device *isp)
         isp_reg_readl(isp, OMAP3_ISP_IOMEM_MAIN, ISP_REVISION);
 }
 
+/* -----------------------------------------------------------------------------
+ * XCLK
+ */
+
+#define to_isp_xclk(_hw)        container_of(_hw, struct isp_xclk, hw)
+
+static void isp_xclk_update(struct isp_xclk *xclk, u32 divider)
+{
+        switch (xclk->id) {
+        case ISP_XCLK_A:
+                isp_reg_clr_set(xclk->isp, OMAP3_ISP_IOMEM_MAIN, ISP_TCTRL_CTRL,
+                                ISPTCTRL_CTRL_DIVA_MASK,
+                                divider << ISPTCTRL_CTRL_DIVA_SHIFT);
+                break;
+        case ISP_XCLK_B:
+                isp_reg_clr_set(xclk->isp, OMAP3_ISP_IOMEM_MAIN, ISP_TCTRL_CTRL,
+                                ISPTCTRL_CTRL_DIVB_MASK,
+                                divider << ISPTCTRL_CTRL_DIVB_SHIFT);
+                break;
+        }
+}
+
+static int isp_xclk_prepare(struct clk_hw *hw)
+{
+        struct isp_xclk *xclk = to_isp_xclk(hw);
+
+        omap3isp_get(xclk->isp);
+
+        return 0;
+}
+
+static void isp_xclk_unprepare(struct clk_hw *hw)
+{
+        struct isp_xclk *xclk = to_isp_xclk(hw);
+
+        omap3isp_put(xclk->isp);
+}
+
+static int isp_xclk_enable(struct clk_hw *hw)
+{
+        struct isp_xclk *xclk = to_isp_xclk(hw);
+        unsigned long flags;
+
+        spin_lock_irqsave(&xclk->lock, flags);
+        isp_xclk_update(xclk, xclk->divider);
+        xclk->enabled = true;
+        spin_unlock_irqrestore(&xclk->lock, flags);
+
+        return 0;
+}
+
+static void isp_xclk_disable(struct clk_hw *hw)
+{
+        struct isp_xclk *xclk = to_isp_xclk(hw);
+        unsigned long flags;
+
+        spin_lock_irqsave(&xclk->lock, flags);
+        isp_xclk_update(xclk, 0);
+        xclk->enabled = false;
+        spin_unlock_irqrestore(&xclk->lock, flags);
+}
+
+static unsigned long isp_xclk_recalc_rate(struct clk_hw *hw,
+                                          unsigned long parent_rate)
+{
+        struct isp_xclk *xclk = to_isp_xclk(hw);
+
+        return parent_rate / xclk->divider;
+}
+
+static u32 isp_xclk_calc_divider(unsigned long *rate, unsigned long parent_rate)
+{
+        u32 divider;
+
+        if (*rate >= parent_rate) {
+                *rate = parent_rate;
+                return ISPTCTRL_CTRL_DIV_BYPASS;
+        }
+
+        divider = DIV_ROUND_CLOSEST(parent_rate, *rate);
+        if (divider >= ISPTCTRL_CTRL_DIV_BYPASS)
+                divider = ISPTCTRL_CTRL_DIV_BYPASS - 1;
+
+        *rate = parent_rate / divider;
+        return divider;
+}
+
+static long isp_xclk_round_rate(struct clk_hw *hw, unsigned long rate,
+                                unsigned long *parent_rate)
+{
+        isp_xclk_calc_divider(&rate, *parent_rate);
+        return rate;
+}
+
+static int isp_xclk_set_rate(struct clk_hw *hw, unsigned long rate,
+                             unsigned long parent_rate)
+{
+        struct isp_xclk *xclk = to_isp_xclk(hw);
+        unsigned long flags;
+        u32 divider;
+
+        divider = isp_xclk_calc_divider(&rate, parent_rate);
+
+        spin_lock_irqsave(&xclk->lock, flags);
+
+        xclk->divider = divider;
+        if (xclk->enabled)
+                isp_xclk_update(xclk, divider);
+
+        spin_unlock_irqrestore(&xclk->lock, flags);
+
+        dev_dbg(xclk->isp->dev, "%s: cam_xclk%c set to %lu Hz (div %u)\n",
+                __func__, xclk->id == ISP_XCLK_A ? 'a' : 'b', rate, divider);
+        return 0;
+}
+
+static const struct clk_ops isp_xclk_ops = {
+        .prepare = isp_xclk_prepare,
+        .unprepare = isp_xclk_unprepare,
+        .enable = isp_xclk_enable,
+        .disable = isp_xclk_disable,
+        .recalc_rate = isp_xclk_recalc_rate,
+        .round_rate = isp_xclk_round_rate,
+        .set_rate = isp_xclk_set_rate,
+};
+
+static const char *isp_xclk_parent_name = "cam_mclk";
+
+static const struct clk_init_data isp_xclk_init_data = {
+        .name = "cam_xclk",
+        .ops = &isp_xclk_ops,
+        .parent_names = &isp_xclk_parent_name,
+        .num_parents = 1,
+};
+
+static int isp_xclk_init(struct isp_device *isp)
+{
+        struct isp_platform_data *pdata = isp->pdata;
+        struct clk_init_data init;
+        unsigned int i;
+
+        for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i) {
+                struct isp_xclk *xclk = &isp->xclks[i];
+                struct clk *clk;
+
+                xclk->isp = isp;
+                xclk->id = i == 0 ? ISP_XCLK_A : ISP_XCLK_B;
+                xclk->divider = 1;
+                spin_lock_init(&xclk->lock);
+
+                init.name = i == 0 ? "cam_xclka" : "cam_xclkb";
+                init.ops = &isp_xclk_ops;
+                init.parent_names = &isp_xclk_parent_name;
+                init.num_parents = 1;
+
+                xclk->hw.init = &init;
+
+                clk = devm_clk_register(isp->dev, &xclk->hw);
+                if (IS_ERR(clk))
+                        return PTR_ERR(clk);
+
+                if (pdata->xclks[i].con_id == NULL &&
+                    pdata->xclks[i].dev_id == NULL)
+                        continue;
+
+                xclk->lookup = kzalloc(sizeof(*xclk->lookup), GFP_KERNEL);
+                if (xclk->lookup == NULL)
+                        return -ENOMEM;
+
+                xclk->lookup->con_id = pdata->xclks[i].con_id;
+                xclk->lookup->dev_id = pdata->xclks[i].dev_id;
+                xclk->lookup->clk = clk;
+
+                clkdev_add(xclk->lookup);
+        }
+
+        return 0;
+}
+
+static void isp_xclk_cleanup(struct isp_device *isp)
+{
+        unsigned int i;
+
+        for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i) {
+                struct isp_xclk *xclk = &isp->xclks[i];
+
+                if (xclk->lookup)
+                        clkdev_drop(xclk->lookup);
+        }
+}
+
+/* -----------------------------------------------------------------------------
+ * Interrupts
+ */
+
 /*
  * isp_enable_interrupts - Enable ISP interrupts.
  * @isp: OMAP3 ISP device
@@ -180,80 +376,6 @@ static void isp_disable_interrupts(struct isp_device *isp)
         isp_reg_writel(isp, 0, OMAP3_ISP_IOMEM_MAIN, ISP_IRQ0ENABLE);
 }
 
-/**
- * isp_set_xclk - Configures the specified cam_xclk to the desired frequency.
- * @isp: OMAP3 ISP device
- * @xclk: Desired frequency of the clock in Hz. 0 = stable low, 1 is stable high
- * @xclksel: XCLK to configure (0 = A, 1 = B).
- *
- * Configures the specified MCLK divisor in the ISP timing control register
- * (TCTRL_CTRL) to generate the desired xclk clock value.
- *
- * Divisor = cam_mclk_hz / xclk
- *
- * Returns the final frequency that is actually being generated
- **/
-static u32 isp_set_xclk(struct isp_device *isp, u32 xclk, u8 xclksel)
-{
-        u32 divisor;
-        u32 currentxclk;
-        unsigned long mclk_hz;
-
-        if (!omap3isp_get(isp))
-                return 0;
-
-        mclk_hz = clk_get_rate(isp->clock[ISP_CLK_CAM_MCLK]);
-
-        if (xclk >= mclk_hz) {
-                divisor = ISPTCTRL_CTRL_DIV_BYPASS;
-                currentxclk = mclk_hz;
-        } else if (xclk >= 2) {
-                divisor = mclk_hz / xclk;
-                if (divisor >= ISPTCTRL_CTRL_DIV_BYPASS)
-                        divisor = ISPTCTRL_CTRL_DIV_BYPASS - 1;
-                currentxclk = mclk_hz / divisor;
-        } else {
-                divisor = xclk;
-                currentxclk = 0;
-        }
-
-        switch (xclksel) {
-        case ISP_XCLK_A:
-                isp_reg_clr_set(isp, OMAP3_ISP_IOMEM_MAIN, ISP_TCTRL_CTRL,
-                                ISPTCTRL_CTRL_DIVA_MASK,
-                                divisor << ISPTCTRL_CTRL_DIVA_SHIFT);
-                dev_dbg(isp->dev, "isp_set_xclk(): cam_xclka set to %d Hz\n",
-                        currentxclk);
-                break;
-        case ISP_XCLK_B:
-                isp_reg_clr_set(isp, OMAP3_ISP_IOMEM_MAIN, ISP_TCTRL_CTRL,
-                                ISPTCTRL_CTRL_DIVB_MASK,
-                                divisor << ISPTCTRL_CTRL_DIVB_SHIFT);
-                dev_dbg(isp->dev, "isp_set_xclk(): cam_xclkb set to %d Hz\n",
-                        currentxclk);
-                break;
-        case ISP_XCLK_NONE:
-        default:
-                omap3isp_put(isp);
-                dev_dbg(isp->dev, "ISP_ERR: isp_set_xclk(): Invalid requested "
-                        "xclk. Must be 0 (A) or 1 (B).\n");
-                return -EINVAL;
-        }
-
-        /* Do we go from stable whatever to clock? */
-        if (divisor >= 2 && isp->xclk_divisor[xclksel - 1] < 2)
-                omap3isp_get(isp);
-        /* Stopping the clock. */
-        else if (divisor < 2 && isp->xclk_divisor[xclksel - 1] >= 2)
-                omap3isp_put(isp);
-
-        isp->xclk_divisor[xclksel - 1] = divisor;
-
-        omap3isp_put(isp);
-
-        return currentxclk;
-}
-
 /*
  * isp_core_init - ISP core settings
  * @isp: OMAP3 ISP device
@@ -1969,6 +2091,7 @@ static int isp_remove(struct platform_device *pdev)
 
         isp_unregister_entities(isp);
         isp_cleanup_modules(isp);
+        isp_xclk_cleanup(isp);
 
         __omap3isp_get(isp, false);
         iommu_detach_device(isp->domain, &pdev->dev);
@@ -2042,7 +2165,6 @@ static int isp_probe(struct platform_device *pdev)
         }
 
         isp->autoidle = autoidle;
-        isp->platform_cb.set_xclk = isp_set_xclk;
 
         mutex_init(&isp->isp_mutex);
         spin_lock_init(&isp->stat_lock);
@@ -2093,6 +2215,10 @@ static int isp_probe(struct platform_device *pdev)
         if (ret < 0)
                 goto error_isp;
 
+        ret = isp_xclk_init(isp);
+        if (ret < 0)
+                goto error_isp;
+
         /* Memory resources */
         for (m = 0; m < ARRAY_SIZE(isp_res_maps); m++)
                 if (isp->revision == isp_res_maps[m].isp_rev)
@@ -2162,6 +2288,7 @@ detach_dev:
 free_domain:
         iommu_domain_free(isp->domain);
 error_isp:
+        isp_xclk_cleanup(isp);
         omap3isp_put(isp);
 error:
         platform_set_drvdata(pdev, NULL);
diff --git a/drivers/media/platform/omap3isp/isp.h b/drivers/media/platform/omap3isp/isp.h
index c77e1f2ae5ca..cd3eff45ae7d 100644
--- a/drivers/media/platform/omap3isp/isp.h
+++ b/drivers/media/platform/omap3isp/isp.h
@@ -29,6 +29,7 @@
 
 #include <media/omap3isp.h>
 #include <media/v4l2-device.h>
+#include <linux/clk-provider.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/iommu.h>
@@ -125,8 +126,20 @@ struct isp_reg {
         u32 val;
 };
 
-struct isp_platform_callback {
-        u32 (*set_xclk)(struct isp_device *isp, u32 xclk, u8 xclksel);
+enum isp_xclk_id {
+        ISP_XCLK_A,
+        ISP_XCLK_B,
+};
+
+struct isp_xclk {
+        struct isp_device *isp;
+        struct clk_hw hw;
+        struct clk_lookup *lookup;
+        enum isp_xclk_id id;
+
+        spinlock_t lock;        /* Protects enabled and divider */
+        bool enabled;
+        unsigned int divider;
 };
 
 /*
@@ -149,6 +162,7 @@ struct isp_platform_callback {
  * @cam_mclk: Pointer to camera functional clock structure.
  * @csi2_fck: Pointer to camera CSI2 complexIO clock structure.
  * @l3_ick: Pointer to OMAP3 L3 bus interface clock.
+ * @xclks: External clocks provided by the ISP
  * @irq: Currently attached ISP ISR callbacks information structure.
  * @isp_af: Pointer to current settings for ISP AutoFocus SCM.
  * @isp_hist: Pointer to current settings for ISP Histogram SCM.
@@ -185,12 +199,12 @@ struct isp_device {
         int has_context;
         int ref_count;
         unsigned int autoidle;
-        u32 xclk_divisor[2];    /* Two clocks, a and b. */
 #define ISP_CLK_CAM_ICK         0
 #define ISP_CLK_CAM_MCLK        1
 #define ISP_CLK_CSI2_FCK        2
 #define ISP_CLK_L3_ICK          3
         struct clk *clock[4];
+        struct isp_xclk xclks[2];
 
         /* ISP modules */
         struct ispstat isp_af;
@@ -209,8 +223,6 @@ struct isp_device {
         unsigned int subclk_resources;
 
         struct iommu_domain *domain;
-
-        struct isp_platform_callback platform_cb;
 };
 
 #define v4l2_dev_to_isp_device(dev) \