summaryrefslogtreecommitdiff
path: root/arch/arm/mach-ep93xx/clock.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-ep93xx/clock.c')
-rw-r--r--arch/arm/mach-ep93xx/clock.c563
1 files changed, 563 insertions, 0 deletions
diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c
new file mode 100644
index 00000000..c95dbce2
--- /dev/null
+++ b/arch/arm/mach-ep93xx/clock.c
@@ -0,0 +1,563 @@
+/*
+ * arch/arm/mach-ep93xx/clock.c
+ * Clock control for Cirrus EP93xx chips.
+ *
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ */
+
+#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/clkdev.h>
+
+#include <mach/hardware.h>
+
+#include <asm/div64.h>
+
+#include "soc.h"
+
+struct clk {
+ struct clk *parent;
+ unsigned long rate;
+ int users;
+ int sw_locked;
+ void __iomem *enable_reg;
+ u32 enable_mask;
+
+ unsigned long (*get_rate)(struct clk *clk);
+ int (*set_rate)(struct clk *clk, unsigned long rate);
+};
+
+
+static unsigned long get_uart_rate(struct clk *clk);
+
+static int set_keytchclk_rate(struct clk *clk, unsigned long rate);
+static int set_div_rate(struct clk *clk, unsigned long rate);
+static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate);
+static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate);
+
+static struct clk clk_xtali = {
+ .rate = EP93XX_EXT_CLK_RATE,
+};
+static struct clk clk_uart1 = {
+ .parent = &clk_xtali,
+ .sw_locked = 1,
+ .enable_reg = EP93XX_SYSCON_DEVCFG,
+ .enable_mask = EP93XX_SYSCON_DEVCFG_U1EN,
+ .get_rate = get_uart_rate,
+};
+static struct clk clk_uart2 = {
+ .parent = &clk_xtali,
+ .sw_locked = 1,
+ .enable_reg = EP93XX_SYSCON_DEVCFG,
+ .enable_mask = EP93XX_SYSCON_DEVCFG_U2EN,
+ .get_rate = get_uart_rate,
+};
+static struct clk clk_uart3 = {
+ .parent = &clk_xtali,
+ .sw_locked = 1,
+ .enable_reg = EP93XX_SYSCON_DEVCFG,
+ .enable_mask = EP93XX_SYSCON_DEVCFG_U3EN,
+ .get_rate = get_uart_rate,
+};
+static struct clk clk_pll1 = {
+ .parent = &clk_xtali,
+};
+static struct clk clk_f = {
+ .parent = &clk_pll1,
+};
+static struct clk clk_h = {
+ .parent = &clk_pll1,
+};
+static struct clk clk_p = {
+ .parent = &clk_pll1,
+};
+static struct clk clk_pll2 = {
+ .parent = &clk_xtali,
+};
+static struct clk clk_usb_host = {
+ .parent = &clk_pll2,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_USH_EN,
+};
+static struct clk clk_keypad = {
+ .parent = &clk_xtali,
+ .sw_locked = 1,
+ .enable_reg = EP93XX_SYSCON_KEYTCHCLKDIV,
+ .enable_mask = EP93XX_SYSCON_KEYTCHCLKDIV_KEN,
+ .set_rate = set_keytchclk_rate,
+};
+static struct clk clk_spi = {
+ .parent = &clk_xtali,
+ .rate = EP93XX_EXT_CLK_RATE,
+};
+static struct clk clk_pwm = {
+ .parent = &clk_xtali,
+ .rate = EP93XX_EXT_CLK_RATE,
+};
+
+static struct clk clk_video = {
+ .sw_locked = 1,
+ .enable_reg = EP93XX_SYSCON_VIDCLKDIV,
+ .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE,
+ .set_rate = set_div_rate,
+};
+
+static struct clk clk_i2s_mclk = {
+ .sw_locked = 1,
+ .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
+ .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE,
+ .set_rate = set_div_rate,
+};
+
+static struct clk clk_i2s_sclk = {
+ .sw_locked = 1,
+ .parent = &clk_i2s_mclk,
+ .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
+ .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA,
+ .set_rate = set_i2s_sclk_rate,
+};
+
+static struct clk clk_i2s_lrclk = {
+ .sw_locked = 1,
+ .parent = &clk_i2s_sclk,
+ .enable_reg = EP93XX_SYSCON_I2SCLKDIV,
+ .enable_mask = EP93XX_SYSCON_I2SCLKDIV_SENA,
+ .set_rate = set_i2s_lrclk_rate,
+};
+
+/* DMA Clocks */
+static struct clk clk_m2p0 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P0,
+};
+static struct clk clk_m2p1 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P1,
+};
+static struct clk clk_m2p2 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P2,
+};
+static struct clk clk_m2p3 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P3,
+};
+static struct clk clk_m2p4 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P4,
+};
+static struct clk clk_m2p5 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P5,
+};
+static struct clk clk_m2p6 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P6,
+};
+static struct clk clk_m2p7 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P7,
+};
+static struct clk clk_m2p8 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P8,
+};
+static struct clk clk_m2p9 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2P9,
+};
+static struct clk clk_m2m0 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M0,
+};
+static struct clk clk_m2m1 = {
+ .parent = &clk_h,
+ .enable_reg = EP93XX_SYSCON_PWRCNT,
+ .enable_mask = EP93XX_SYSCON_PWRCNT_DMA_M2M1,
+};
+
+#define INIT_CK(dev,con,ck) \
+ { .dev_id = dev, .con_id = con, .clk = ck }
+
+static struct clk_lookup clocks[] = {
+ INIT_CK(NULL, "xtali", &clk_xtali),
+ INIT_CK("apb:uart1", NULL, &clk_uart1),
+ INIT_CK("apb:uart2", NULL, &clk_uart2),
+ INIT_CK("apb:uart3", NULL, &clk_uart3),
+ INIT_CK(NULL, "pll1", &clk_pll1),
+ INIT_CK(NULL, "fclk", &clk_f),
+ INIT_CK(NULL, "hclk", &clk_h),
+ INIT_CK(NULL, "apb_pclk", &clk_p),
+ INIT_CK(NULL, "pll2", &clk_pll2),
+ INIT_CK("ep93xx-ohci", NULL, &clk_usb_host),
+ INIT_CK("ep93xx-keypad", NULL, &clk_keypad),
+ INIT_CK("ep93xx-fb", NULL, &clk_video),
+ INIT_CK("ep93xx-spi.0", NULL, &clk_spi),
+ INIT_CK("ep93xx-i2s", "mclk", &clk_i2s_mclk),
+ INIT_CK("ep93xx-i2s", "sclk", &clk_i2s_sclk),
+ INIT_CK("ep93xx-i2s", "lrclk", &clk_i2s_lrclk),
+ INIT_CK(NULL, "pwm_clk", &clk_pwm),
+ INIT_CK(NULL, "m2p0", &clk_m2p0),
+ INIT_CK(NULL, "m2p1", &clk_m2p1),
+ INIT_CK(NULL, "m2p2", &clk_m2p2),
+ INIT_CK(NULL, "m2p3", &clk_m2p3),
+ INIT_CK(NULL, "m2p4", &clk_m2p4),
+ INIT_CK(NULL, "m2p5", &clk_m2p5),
+ INIT_CK(NULL, "m2p6", &clk_m2p6),
+ INIT_CK(NULL, "m2p7", &clk_m2p7),
+ INIT_CK(NULL, "m2p8", &clk_m2p8),
+ INIT_CK(NULL, "m2p9", &clk_m2p9),
+ INIT_CK(NULL, "m2m0", &clk_m2m0),
+ INIT_CK(NULL, "m2m1", &clk_m2m1),
+};
+
+static DEFINE_SPINLOCK(clk_lock);
+
+static void __clk_enable(struct clk *clk)
+{
+ if (!clk->users++) {
+ if (clk->parent)
+ __clk_enable(clk->parent);
+
+ if (clk->enable_reg) {
+ u32 v;
+
+ v = __raw_readl(clk->enable_reg);
+ v |= clk->enable_mask;
+ if (clk->sw_locked)
+ ep93xx_syscon_swlocked_write(v, clk->enable_reg);
+ else
+ __raw_writel(v, clk->enable_reg);
+ }
+ }
+}
+
+int clk_enable(struct clk *clk)
+{
+ unsigned long flags;
+
+ if (!clk)
+ return -EINVAL;
+
+ spin_lock_irqsave(&clk_lock, flags);
+ __clk_enable(clk);
+ spin_unlock_irqrestore(&clk_lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+static void __clk_disable(struct clk *clk)
+{
+ if (!--clk->users) {
+ if (clk->enable_reg) {
+ u32 v;
+
+ v = __raw_readl(clk->enable_reg);
+ v &= ~clk->enable_mask;
+ if (clk->sw_locked)
+ ep93xx_syscon_swlocked_write(v, clk->enable_reg);
+ else
+ __raw_writel(v, clk->enable_reg);
+ }
+
+ if (clk->parent)
+ __clk_disable(clk->parent);
+ }
+}
+
+void clk_disable(struct clk *clk)
+{
+ unsigned long flags;
+
+ if (!clk)
+ return;
+
+ spin_lock_irqsave(&clk_lock, flags);
+ __clk_disable(clk);
+ spin_unlock_irqrestore(&clk_lock, flags);
+}
+EXPORT_SYMBOL(clk_disable);
+
+static unsigned long get_uart_rate(struct clk *clk)
+{
+ unsigned long rate = clk_get_rate(clk->parent);
+ u32 value;
+
+ value = __raw_readl(EP93XX_SYSCON_PWRCNT);
+ if (value & EP93XX_SYSCON_PWRCNT_UARTBAUD)
+ return rate;
+ else
+ return rate / 2;
+}
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+ if (clk->get_rate)
+ return clk->get_rate(clk);
+
+ return clk->rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+static int set_keytchclk_rate(struct clk *clk, unsigned long rate)
+{
+ u32 val;
+ u32 div_bit;
+
+ val = __raw_readl(clk->enable_reg);
+
+ /*
+ * The Key Matrix and ADC clocks are configured using the same
+ * System Controller register. The clock used will be either
+ * 1/4 or 1/16 the external clock rate depending on the
+ * EP93XX_SYSCON_KEYTCHCLKDIV_KDIV/EP93XX_SYSCON_KEYTCHCLKDIV_ADIV
+ * bit being set or cleared.
+ */
+ div_bit = clk->enable_mask >> 15;
+
+ if (rate == EP93XX_KEYTCHCLK_DIV4)
+ val |= div_bit;
+ else if (rate == EP93XX_KEYTCHCLK_DIV16)
+ val &= ~div_bit;
+ else
+ return -EINVAL;
+
+ ep93xx_syscon_swlocked_write(val, clk->enable_reg);
+ clk->rate = rate;
+ return 0;
+}
+
+static int calc_clk_div(struct clk *clk, unsigned long rate,
+ int *psel, int *esel, int *pdiv, int *div)
+{
+ struct clk *mclk;
+ unsigned long max_rate, actual_rate, mclk_rate, rate_err = -1;
+ int i, found = 0, __div = 0, __pdiv = 0;
+
+ /* Don't exceed the maximum rate */
+ max_rate = max3(clk_pll1.rate / 4, clk_pll2.rate / 4, clk_xtali.rate / 4);
+ rate = min(rate, max_rate);
+
+ /*
+ * Try the two pll's and the external clock
+ * Because the valid predividers are 2, 2.5 and 3, we multiply
+ * all the clocks by 2 to avoid floating point math.
+ *
+ * This is based on the algorithm in the ep93xx raster guide:
+ * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf
+ *
+ */
+ for (i = 0; i < 3; i++) {
+ if (i == 0)
+ mclk = &clk_xtali;
+ else if (i == 1)
+ mclk = &clk_pll1;
+ else
+ mclk = &clk_pll2;
+ mclk_rate = mclk->rate * 2;
+
+ /* Try each predivider value */
+ for (__pdiv = 4; __pdiv <= 6; __pdiv++) {
+ __div = mclk_rate / (rate * __pdiv);
+ if (__div < 2 || __div > 127)
+ continue;
+
+ actual_rate = mclk_rate / (__pdiv * __div);
+
+ if (!found || abs(actual_rate - rate) < rate_err) {
+ *pdiv = __pdiv - 3;
+ *div = __div;
+ *psel = (i == 2);
+ *esel = (i != 0);
+ clk->parent = mclk;
+ clk->rate = actual_rate;
+ rate_err = abs(actual_rate - rate);
+ found = 1;
+ }
+ }
+ }
+
+ if (!found)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int set_div_rate(struct clk *clk, unsigned long rate)
+{
+ int err, psel = 0, esel = 0, pdiv = 0, div = 0;
+ u32 val;
+
+ err = calc_clk_div(clk, rate, &psel, &esel, &pdiv, &div);
+ if (err)
+ return err;
+
+ /* Clear the esel, psel, pdiv and div bits */
+ val = __raw_readl(clk->enable_reg);
+ val &= ~0x7fff;
+
+ /* Set the new esel, psel, pdiv and div bits for the new clock rate */
+ val |= (esel ? EP93XX_SYSCON_CLKDIV_ESEL : 0) |
+ (psel ? EP93XX_SYSCON_CLKDIV_PSEL : 0) |
+ (pdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | div;
+ ep93xx_syscon_swlocked_write(val, clk->enable_reg);
+ return 0;
+}
+
+static int set_i2s_sclk_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned val = __raw_readl(clk->enable_reg);
+
+ if (rate == clk_i2s_mclk.rate / 2)
+ ep93xx_syscon_swlocked_write(val & ~EP93XX_I2SCLKDIV_SDIV,
+ clk->enable_reg);
+ else if (rate == clk_i2s_mclk.rate / 4)
+ ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_SDIV,
+ clk->enable_reg);
+ else
+ return -EINVAL;
+
+ clk_i2s_sclk.rate = rate;
+ return 0;
+}
+
+static int set_i2s_lrclk_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned val = __raw_readl(clk->enable_reg) &
+ ~EP93XX_I2SCLKDIV_LRDIV_MASK;
+
+ if (rate == clk_i2s_sclk.rate / 32)
+ ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV32,
+ clk->enable_reg);
+ else if (rate == clk_i2s_sclk.rate / 64)
+ ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV64,
+ clk->enable_reg);
+ else if (rate == clk_i2s_sclk.rate / 128)
+ ep93xx_syscon_swlocked_write(val | EP93XX_I2SCLKDIV_LRDIV128,
+ clk->enable_reg);
+ else
+ return -EINVAL;
+
+ clk_i2s_lrclk.rate = rate;
+ return 0;
+}
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+ if (clk->set_rate)
+ return clk->set_rate(clk, rate);
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+
+static char fclk_divisors[] = { 1, 2, 4, 8, 16, 1, 1, 1 };
+static char hclk_divisors[] = { 1, 2, 4, 5, 6, 8, 16, 32 };
+static char pclk_divisors[] = { 1, 2, 4, 8 };
+
+/*
+ * PLL rate = 14.7456 MHz * (X1FBD + 1) * (X2FBD + 1) / (X2IPD + 1) / 2^PS
+ */
+static unsigned long calc_pll_rate(u32 config_word)
+{
+ unsigned long long rate;
+ int i;
+
+ rate = clk_xtali.rate;
+ rate *= ((config_word >> 11) & 0x1f) + 1; /* X1FBD */
+ rate *= ((config_word >> 5) & 0x3f) + 1; /* X2FBD */
+ do_div(rate, (config_word & 0x1f) + 1); /* X2IPD */
+ for (i = 0; i < ((config_word >> 16) & 3); i++) /* PS */
+ rate >>= 1;
+
+ return (unsigned long)rate;
+}
+
+static void __init ep93xx_dma_clock_init(void)
+{
+ clk_m2p0.rate = clk_h.rate;
+ clk_m2p1.rate = clk_h.rate;
+ clk_m2p2.rate = clk_h.rate;
+ clk_m2p3.rate = clk_h.rate;
+ clk_m2p4.rate = clk_h.rate;
+ clk_m2p5.rate = clk_h.rate;
+ clk_m2p6.rate = clk_h.rate;
+ clk_m2p7.rate = clk_h.rate;
+ clk_m2p8.rate = clk_h.rate;
+ clk_m2p9.rate = clk_h.rate;
+ clk_m2m0.rate = clk_h.rate;
+ clk_m2m1.rate = clk_h.rate;
+}
+
+static int __init ep93xx_clock_init(void)
+{
+ u32 value;
+
+ /* Determine the bootloader configured pll1 rate */
+ value = __raw_readl(EP93XX_SYSCON_CLKSET1);
+ if (!(value & EP93XX_SYSCON_CLKSET1_NBYP1))
+ clk_pll1.rate = clk_xtali.rate;
+ else
+ clk_pll1.rate = calc_pll_rate(value);
+
+ /* Initialize the pll1 derived clocks */
+ clk_f.rate = clk_pll1.rate / fclk_divisors[(value >> 25) & 0x7];
+ clk_h.rate = clk_pll1.rate / hclk_divisors[(value >> 20) & 0x7];
+ clk_p.rate = clk_h.rate / pclk_divisors[(value >> 18) & 0x3];
+ ep93xx_dma_clock_init();
+
+ /* Determine the bootloader configured pll2 rate */
+ value = __raw_readl(EP93XX_SYSCON_CLKSET2);
+ if (!(value & EP93XX_SYSCON_CLKSET2_NBYP2))
+ clk_pll2.rate = clk_xtali.rate;
+ else if (value & EP93XX_SYSCON_CLKSET2_PLL2_EN)
+ clk_pll2.rate = calc_pll_rate(value);
+ else
+ clk_pll2.rate = 0;
+
+ /* Initialize the pll2 derived clocks */
+ clk_usb_host.rate = clk_pll2.rate / (((value >> 28) & 0xf) + 1);
+
+ /*
+ * EP93xx SSP clock rate was doubled in version E2. For more information
+ * see:
+ * http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
+ */
+ if (ep93xx_chip_revision() < EP93XX_CHIP_REV_E2)
+ clk_spi.rate /= 2;
+
+ pr_info("PLL1 running at %ld MHz, PLL2 at %ld MHz\n",
+ clk_pll1.rate / 1000000, clk_pll2.rate / 1000000);
+ pr_info("FCLK %ld MHz, HCLK %ld MHz, PCLK %ld MHz\n",
+ clk_f.rate / 1000000, clk_h.rate / 1000000,
+ clk_p.rate / 1000000);
+
+ clkdev_add_table(clocks, ARRAY_SIZE(clocks));
+ return 0;
+}
+postcore_initcall(ep93xx_clock_init);
generated by cgit (git 2.34.1) at 2024-12-20 10:14:47 +0000