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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-01 18:28:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-01 18:28:06 -0700
commit2a2bf85f05e42b12ea6bfe821e2d19221cf93555 (patch)
tree11abcdaef6e4f8307574056998d306d21558b6ed /drivers/clk/clk-vt8500.c
parent11801e9de26992d37cb869cc74f389b6a7677e0e (diff)
parent99261fbad0a16f105b262d7525801697588ba526 (diff)
downloadlinux-2a2bf85f05e42b12ea6bfe821e2d19221cf93555.tar.bz2
Merge tag 'dt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM soc device tree updates from Olof Johansson: "Device tree conversion and enablement branch. Mostly a bunch of new bindings and setup for various platforms, but the Via/Winchip VT8500 platform is also converted over from being 100% legacy to now use device tree for probing. More of that will come for 3.8." Trivial conflicts due to removal of vt8500 files, and one documentation file that was added with slightly different contents both here and in the USb tree. * tag 'dt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (212 commits) arm: vt8500: Fixup for missing gpio.h ARM: LPC32xx: LED fix in PHY3250 DTS file ARM: dt: mmp-dma: add binding file arm: vt8500: Update arch-vt8500 to devicetree support. arm: vt8500: gpio: Devicetree support for arch-vt8500 arm: vt8500: doc: Add device tree bindings for arch-vt8500 devices arm: vt8500: clk: Add Common Clock Framework support video: vt8500: Add devicetree support for vt8500-fb and wm8505-fb serial: vt8500: Add devicetree support for vt8500-serial rtc: vt8500: Add devicetree support for vt8500-rtc arm: vt8500: Add device tree files for VIA/Wondermedia SoC's ARM: tegra: Add Avionic Design Tamonten Evaluation Carrier support ARM: tegra: Add Avionic Design Medcom-Wide support ARM: tegra: Add Avionic Design Plutux support ARM: tegra: Add Avionic Design Tamonten support ARM: tegra: dts: Add pwm label ARM: ux500: Fix SSP register address format ARM: ux500: Apply tc3589x's GPIO/IRQ properties to HREF's DT ARM: ux500: Remove redundant #gpio-cell properties from Snowball DT ARM: ux500: Add all encompassing sound node to the HREF Device Tree ...
Diffstat (limited to 'drivers/clk/clk-vt8500.c')
-rw-r--r--drivers/clk/clk-vt8500.c510
1 files changed, 510 insertions, 0 deletions
diff --git a/drivers/clk/clk-vt8500.c b/drivers/clk/clk-vt8500.c
new file mode 100644
index 000000000000..a885600f5270
--- /dev/null
+++ b/drivers/clk/clk-vt8500.c
@@ -0,0 +1,510 @@
+/*
+ * Clock implementation for VIA/Wondermedia SoC's
+ * Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+
+/* All clocks share the same lock as none can be changed concurrently */
+static DEFINE_SPINLOCK(_lock);
+
+struct clk_device {
+ struct clk_hw hw;
+ void __iomem *div_reg;
+ unsigned int div_mask;
+ void __iomem *en_reg;
+ int en_bit;
+ spinlock_t *lock;
+};
+
+/*
+ * Add new PLL_TYPE_x definitions here as required. Use the first known model
+ * to support the new type as the name.
+ * Add case statements to vtwm_pll_recalc_rate(), vtwm_pll_round_round() and
+ * vtwm_pll_set_rate() to handle the new PLL_TYPE_x
+ */
+
+#define PLL_TYPE_VT8500 0
+#define PLL_TYPE_WM8650 1
+
+struct clk_pll {
+ struct clk_hw hw;
+ void __iomem *reg;
+ spinlock_t *lock;
+ int type;
+};
+
+static void __iomem *pmc_base;
+
+#define to_clk_device(_hw) container_of(_hw, struct clk_device, hw)
+
+#define VT8500_PMC_BUSY_MASK 0x18
+
+static void vt8500_pmc_wait_busy(void)
+{
+ while (readl(pmc_base) & VT8500_PMC_BUSY_MASK)
+ cpu_relax();
+}
+
+static int vt8500_dclk_enable(struct clk_hw *hw)
+{
+ struct clk_device *cdev = to_clk_device(hw);
+ u32 en_val;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(cdev->lock, flags);
+
+ en_val = readl(cdev->en_reg);
+ en_val |= BIT(cdev->en_bit);
+ writel(en_val, cdev->en_reg);
+
+ spin_unlock_irqrestore(cdev->lock, flags);
+ return 0;
+}
+
+static void vt8500_dclk_disable(struct clk_hw *hw)
+{
+ struct clk_device *cdev = to_clk_device(hw);
+ u32 en_val;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(cdev->lock, flags);
+
+ en_val = readl(cdev->en_reg);
+ en_val &= ~BIT(cdev->en_bit);
+ writel(en_val, cdev->en_reg);
+
+ spin_unlock_irqrestore(cdev->lock, flags);
+}
+
+static int vt8500_dclk_is_enabled(struct clk_hw *hw)
+{
+ struct clk_device *cdev = to_clk_device(hw);
+ u32 en_val = (readl(cdev->en_reg) & BIT(cdev->en_bit));
+
+ return en_val ? 1 : 0;
+}
+
+static unsigned long vt8500_dclk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_device *cdev = to_clk_device(hw);
+ u32 div = readl(cdev->div_reg) & cdev->div_mask;
+
+ /* Special case for SDMMC devices */
+ if ((cdev->div_mask == 0x3F) && (div & BIT(5)))
+ div = 64 * (div & 0x1f);
+
+ /* div == 0 is actually the highest divisor */
+ if (div == 0)
+ div = (cdev->div_mask + 1);
+
+ return parent_rate / div;
+}
+
+static long vt8500_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ u32 divisor = *prate / rate;
+
+ return *prate / divisor;
+}
+
+static int vt8500_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_device *cdev = to_clk_device(hw);
+ u32 divisor = parent_rate / rate;
+ unsigned long flags = 0;
+
+ if (divisor == cdev->div_mask + 1)
+ divisor = 0;
+
+ if (divisor > cdev->div_mask) {
+ pr_err("%s: invalid divisor for clock\n", __func__);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(cdev->lock, flags);
+
+ vt8500_pmc_wait_busy();
+ writel(divisor, cdev->div_reg);
+ vt8500_pmc_wait_busy();
+
+ spin_lock_irqsave(cdev->lock, flags);
+
+ return 0;
+}
+
+
+static const struct clk_ops vt8500_gated_clk_ops = {
+ .enable = vt8500_dclk_enable,
+ .disable = vt8500_dclk_disable,
+ .is_enabled = vt8500_dclk_is_enabled,
+};
+
+static const struct clk_ops vt8500_divisor_clk_ops = {
+ .round_rate = vt8500_dclk_round_rate,
+ .set_rate = vt8500_dclk_set_rate,
+ .recalc_rate = vt8500_dclk_recalc_rate,
+};
+
+static const struct clk_ops vt8500_gated_divisor_clk_ops = {
+ .enable = vt8500_dclk_enable,
+ .disable = vt8500_dclk_disable,
+ .is_enabled = vt8500_dclk_is_enabled,
+ .round_rate = vt8500_dclk_round_rate,
+ .set_rate = vt8500_dclk_set_rate,
+ .recalc_rate = vt8500_dclk_recalc_rate,
+};
+
+#define CLK_INIT_GATED BIT(0)
+#define CLK_INIT_DIVISOR BIT(1)
+#define CLK_INIT_GATED_DIVISOR (CLK_INIT_DIVISOR | CLK_INIT_GATED)
+
+static __init void vtwm_device_clk_init(struct device_node *node)
+{
+ u32 en_reg, div_reg;
+ struct clk *clk;
+ struct clk_device *dev_clk;
+ const char *clk_name = node->name;
+ const char *parent_name;
+ struct clk_init_data init;
+ int rc;
+ int clk_init_flags = 0;
+
+ dev_clk = kzalloc(sizeof(*dev_clk), GFP_KERNEL);
+ if (WARN_ON(!dev_clk))
+ return;
+
+ dev_clk->lock = &_lock;
+
+ rc = of_property_read_u32(node, "enable-reg", &en_reg);
+ if (!rc) {
+ dev_clk->en_reg = pmc_base + en_reg;
+ rc = of_property_read_u32(node, "enable-bit", &dev_clk->en_bit);
+ if (rc) {
+ pr_err("%s: enable-bit property required for gated clock\n",
+ __func__);
+ return;
+ }
+ clk_init_flags |= CLK_INIT_GATED;
+ }
+
+ rc = of_property_read_u32(node, "divisor-reg", &div_reg);
+ if (!rc) {
+ dev_clk->div_reg = pmc_base + div_reg;
+ /*
+ * use 0x1f as the default mask since it covers
+ * almost all the clocks and reduces dts properties
+ */
+ dev_clk->div_mask = 0x1f;
+
+ of_property_read_u32(node, "divisor-mask", &dev_clk->div_mask);
+ clk_init_flags |= CLK_INIT_DIVISOR;
+ }
+
+ of_property_read_string(node, "clock-output-names", &clk_name);
+
+ switch (clk_init_flags) {
+ case CLK_INIT_GATED:
+ init.ops = &vt8500_gated_clk_ops;
+ break;
+ case CLK_INIT_DIVISOR:
+ init.ops = &vt8500_divisor_clk_ops;
+ break;
+ case CLK_INIT_GATED_DIVISOR:
+ init.ops = &vt8500_gated_divisor_clk_ops;
+ break;
+ default:
+ pr_err("%s: Invalid clock description in device tree\n",
+ __func__);
+ kfree(dev_clk);
+ return;
+ }
+
+ init.name = clk_name;
+ init.flags = 0;
+ parent_name = of_clk_get_parent_name(node, 0);
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ dev_clk->hw.init = &init;
+
+ clk = clk_register(NULL, &dev_clk->hw);
+ if (WARN_ON(IS_ERR(clk))) {
+ kfree(dev_clk);
+ return;
+ }
+ rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+ clk_register_clkdev(clk, clk_name, NULL);
+}
+
+
+/* PLL clock related functions */
+
+#define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
+
+/* Helper macros for PLL_VT8500 */
+#define VT8500_PLL_MUL(x) ((x & 0x1F) << 1)
+#define VT8500_PLL_DIV(x) ((x & 0x100) ? 1 : 2)
+
+#define VT8500_BITS_TO_FREQ(r, m, d) \
+ ((r / d) * m)
+
+#define VT8500_BITS_TO_VAL(m, d) \
+ ((d == 2 ? 0 : 0x100) | ((m >> 1) & 0x1F))
+
+/* Helper macros for PLL_WM8650 */
+#define WM8650_PLL_MUL(x) (x & 0x3FF)
+#define WM8650_PLL_DIV(x) (((x >> 10) & 7) * (1 << ((x >> 13) & 3)))
+
+#define WM8650_BITS_TO_FREQ(r, m, d1, d2) \
+ (r * m / (d1 * (1 << d2)))
+
+#define WM8650_BITS_TO_VAL(m, d1, d2) \
+ ((d2 << 13) | (d1 << 10) | (m & 0x3FF))
+
+
+static void vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate,
+ u32 *multiplier, u32 *prediv)
+{
+ unsigned long tclk;
+
+ /* sanity check */
+ if ((rate < parent_rate * 4) || (rate > parent_rate * 62)) {
+ pr_err("%s: requested rate out of range\n", __func__);
+ *multiplier = 0;
+ *prediv = 1;
+ return;
+ }
+ if (rate <= parent_rate * 31)
+ /* use the prediv to double the resolution */
+ *prediv = 2;
+ else
+ *prediv = 1;
+
+ *multiplier = rate / (parent_rate / *prediv);
+ tclk = (parent_rate / *prediv) * *multiplier;
+
+ if (tclk != rate)
+ pr_warn("%s: requested rate %lu, found rate %lu\n", __func__,
+ rate, tclk);
+}
+
+static void wm8650_find_pll_bits(unsigned long rate, unsigned long parent_rate,
+ u32 *multiplier, u32 *divisor1, u32 *divisor2)
+{
+ u32 mul, div1, div2;
+ u32 best_mul, best_div1, best_div2;
+ unsigned long tclk, rate_err, best_err;
+
+ best_err = (unsigned long)-1;
+
+ /* Find the closest match (lower or equal to requested) */
+ for (div1 = 5; div1 >= 3; div1--)
+ for (div2 = 3; div2 >= 0; div2--)
+ for (mul = 3; mul <= 1023; mul++) {
+ tclk = parent_rate * mul / (div1 * (1 << div2));
+ if (tclk > rate)
+ continue;
+ /* error will always be +ve */
+ rate_err = rate - tclk;
+ if (rate_err == 0) {
+ *multiplier = mul;
+ *divisor1 = div1;
+ *divisor2 = div2;
+ return;
+ }
+
+ if (rate_err < best_err) {
+ best_err = rate_err;
+ best_mul = mul;
+ best_div1 = div1;
+ best_div2 = div2;
+ }
+ }
+
+ /* if we got here, it wasn't an exact match */
+ pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate,
+ rate - best_err);
+ *multiplier = mul;
+ *divisor1 = div1;
+ *divisor2 = div2;
+}
+
+static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+ u32 mul, div1, div2;
+ u32 pll_val;
+ unsigned long flags = 0;
+
+ /* sanity check */
+
+ switch (pll->type) {
+ case PLL_TYPE_VT8500:
+ vt8500_find_pll_bits(rate, parent_rate, &mul, &div1);
+ pll_val = VT8500_BITS_TO_VAL(mul, div1);
+ break;
+ case PLL_TYPE_WM8650:
+ wm8650_find_pll_bits(rate, parent_rate, &mul, &div1, &div2);
+ pll_val = WM8650_BITS_TO_VAL(mul, div1, div2);
+ break;
+ default:
+ pr_err("%s: invalid pll type\n", __func__);
+ return 0;
+ }
+
+ spin_lock_irqsave(pll->lock, flags);
+
+ vt8500_pmc_wait_busy();
+ writel(pll_val, pll->reg);
+ vt8500_pmc_wait_busy();
+
+ spin_unlock_irqrestore(pll->lock, flags);
+
+ return 0;
+}
+
+static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+ u32 mul, div1, div2;
+ long round_rate;
+
+ switch (pll->type) {
+ case PLL_TYPE_VT8500:
+ vt8500_find_pll_bits(rate, *prate, &mul, &div1);
+ round_rate = VT8500_BITS_TO_FREQ(*prate, mul, div1);
+ break;
+ case PLL_TYPE_WM8650:
+ wm8650_find_pll_bits(rate, *prate, &mul, &div1, &div2);
+ round_rate = WM8650_BITS_TO_FREQ(*prate, mul, div1, div2);
+ break;
+ default:
+ round_rate = 0;
+ }
+
+ return round_rate;
+}
+
+static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+ u32 pll_val = readl(pll->reg);
+ unsigned long pll_freq;
+
+ switch (pll->type) {
+ case PLL_TYPE_VT8500:
+ pll_freq = parent_rate * VT8500_PLL_MUL(pll_val);
+ pll_freq /= VT8500_PLL_DIV(pll_val);
+ break;
+ case PLL_TYPE_WM8650:
+ pll_freq = parent_rate * WM8650_PLL_MUL(pll_val);
+ pll_freq /= WM8650_PLL_DIV(pll_val);
+ break;
+ default:
+ pll_freq = 0;
+ }
+
+ return pll_freq;
+}
+
+const struct clk_ops vtwm_pll_ops = {
+ .round_rate = vtwm_pll_round_rate,
+ .set_rate = vtwm_pll_set_rate,
+ .recalc_rate = vtwm_pll_recalc_rate,
+};
+
+static __init void vtwm_pll_clk_init(struct device_node *node, int pll_type)
+{
+ u32 reg;
+ struct clk *clk;
+ struct clk_pll *pll_clk;
+ const char *clk_name = node->name;
+ const char *parent_name;
+ struct clk_init_data init;
+ int rc;
+
+ rc = of_property_read_u32(node, "reg", &reg);
+ if (WARN_ON(rc))
+ return;
+
+ pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
+ if (WARN_ON(!pll_clk))
+ return;
+
+ pll_clk->reg = pmc_base + reg;
+ pll_clk->lock = &_lock;
+ pll_clk->type = pll_type;
+
+ of_property_read_string(node, "clock-output-names", &clk_name);
+
+ init.name = clk_name;
+ init.ops = &vtwm_pll_ops;
+ init.flags = 0;
+ parent_name = of_clk_get_parent_name(node, 0);
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ pll_clk->hw.init = &init;
+
+ clk = clk_register(NULL, &pll_clk->hw);
+ if (WARN_ON(IS_ERR(clk))) {
+ kfree(pll_clk);
+ return;
+ }
+ rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
+ clk_register_clkdev(clk, clk_name, NULL);
+}
+
+
+/* Wrappers for initialization functions */
+
+static void __init vt8500_pll_init(struct device_node *node)
+{
+ vtwm_pll_clk_init(node, PLL_TYPE_VT8500);
+}
+
+static void __init wm8650_pll_init(struct device_node *node)
+{
+ vtwm_pll_clk_init(node, PLL_TYPE_WM8650);
+}
+
+static const __initconst struct of_device_id clk_match[] = {
+ { .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
+ { .compatible = "via,vt8500-pll-clock", .data = vt8500_pll_init, },
+ { .compatible = "wm,wm8650-pll-clock", .data = wm8650_pll_init, },
+ { .compatible = "via,vt8500-device-clock",
+ .data = vtwm_device_clk_init, },
+ { /* sentinel */ }
+};
+
+void __init vtwm_clk_init(void __iomem *base)
+{
+ if (!base)
+ return;
+
+ pmc_base = base;
+
+ of_clk_init(clk_match);
+}