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path: root/drivers/clk/clk-xgene.c
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-rw-r--r--drivers/clk/clk-xgene.c521
1 files changed, 521 insertions, 0 deletions
diff --git a/drivers/clk/clk-xgene.c b/drivers/clk/clk-xgene.c
new file mode 100644
index 000000000000..dd8a62d8f11f
--- /dev/null
+++ b/drivers/clk/clk-xgene.c
@@ -0,0 +1,521 @@
+/*
+ * clk-xgene.c - AppliedMicro X-Gene Clock Interface
+ *
+ * Copyright (c) 2013, Applied Micro Circuits Corporation
+ * Author: Loc Ho <lho@apm.com>
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <asm/setup.h>
+
+/* Register SCU_PCPPLL bit fields */
+#define N_DIV_RD(src) (((src) & 0x000001ff))
+
+/* Register SCU_SOCPLL bit fields */
+#define CLKR_RD(src) (((src) & 0x07000000)>>24)
+#define CLKOD_RD(src) (((src) & 0x00300000)>>20)
+#define REGSPEC_RESET_F1_MASK 0x00010000
+#define CLKF_RD(src) (((src) & 0x000001ff))
+
+#define XGENE_CLK_DRIVER_VER "0.1"
+
+static DEFINE_SPINLOCK(clk_lock);
+
+static inline u32 xgene_clk_read(void *csr)
+{
+ return readl_relaxed(csr);
+}
+
+static inline void xgene_clk_write(u32 data, void *csr)
+{
+ return writel_relaxed(data, csr);
+}
+
+/* PLL Clock */
+enum xgene_pll_type {
+ PLL_TYPE_PCP = 0,
+ PLL_TYPE_SOC = 1,
+};
+
+struct xgene_clk_pll {
+ struct clk_hw hw;
+ const char *name;
+ void __iomem *reg;
+ spinlock_t *lock;
+ u32 pll_offset;
+ enum xgene_pll_type type;
+};
+
+#define to_xgene_clk_pll(_hw) container_of(_hw, struct xgene_clk_pll, hw)
+
+static int xgene_clk_pll_is_enabled(struct clk_hw *hw)
+{
+ struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
+ u32 data;
+
+ data = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
+ pr_debug("%s pll %s\n", pllclk->name,
+ data & REGSPEC_RESET_F1_MASK ? "disabled" : "enabled");
+
+ return data & REGSPEC_RESET_F1_MASK ? 0 : 1;
+}
+
+static unsigned long xgene_clk_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct xgene_clk_pll *pllclk = to_xgene_clk_pll(hw);
+ unsigned long fref;
+ unsigned long fvco;
+ u32 pll;
+ u32 nref;
+ u32 nout;
+ u32 nfb;
+
+ pll = xgene_clk_read(pllclk->reg + pllclk->pll_offset);
+
+ if (pllclk->type == PLL_TYPE_PCP) {
+ /*
+ * PLL VCO = Reference clock * NF
+ * PCP PLL = PLL_VCO / 2
+ */
+ nout = 2;
+ fvco = parent_rate * (N_DIV_RD(pll) + 4);
+ } else {
+ /*
+ * Fref = Reference Clock / NREF;
+ * Fvco = Fref * NFB;
+ * Fout = Fvco / NOUT;
+ */
+ nref = CLKR_RD(pll) + 1;
+ nout = CLKOD_RD(pll) + 1;
+ nfb = CLKF_RD(pll);
+ fref = parent_rate / nref;
+ fvco = fref * nfb;
+ }
+ pr_debug("%s pll recalc rate %ld parent %ld\n", pllclk->name,
+ fvco / nout, parent_rate);
+
+ return fvco / nout;
+}
+
+const struct clk_ops xgene_clk_pll_ops = {
+ .is_enabled = xgene_clk_pll_is_enabled,
+ .recalc_rate = xgene_clk_pll_recalc_rate,
+};
+
+static struct clk *xgene_register_clk_pll(struct device *dev,
+ const char *name, const char *parent_name,
+ unsigned long flags, void __iomem *reg, u32 pll_offset,
+ u32 type, spinlock_t *lock)
+{
+ struct xgene_clk_pll *apmclk;
+ struct clk *clk;
+ struct clk_init_data init;
+
+ /* allocate the APM clock structure */
+ apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
+ if (!apmclk) {
+ pr_err("%s: could not allocate APM clk\n", __func__);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ init.name = name;
+ init.ops = &xgene_clk_pll_ops;
+ init.flags = flags;
+ init.parent_names = parent_name ? &parent_name : NULL;
+ init.num_parents = parent_name ? 1 : 0;
+
+ apmclk->name = name;
+ apmclk->reg = reg;
+ apmclk->lock = lock;
+ apmclk->pll_offset = pll_offset;
+ apmclk->type = type;
+ apmclk->hw.init = &init;
+
+ /* Register the clock */
+ clk = clk_register(dev, &apmclk->hw);
+ if (IS_ERR(clk)) {
+ pr_err("%s: could not register clk %s\n", __func__, name);
+ kfree(apmclk);
+ return NULL;
+ }
+ return clk;
+}
+
+static void xgene_pllclk_init(struct device_node *np, enum xgene_pll_type pll_type)
+{
+ const char *clk_name = np->full_name;
+ struct clk *clk;
+ void *reg;
+
+ reg = of_iomap(np, 0);
+ if (reg == NULL) {
+ pr_err("Unable to map CSR register for %s\n", np->full_name);
+ return;
+ }
+ of_property_read_string(np, "clock-output-names", &clk_name);
+ clk = xgene_register_clk_pll(NULL,
+ clk_name, of_clk_get_parent_name(np, 0),
+ CLK_IS_ROOT, reg, 0, pll_type, &clk_lock);
+ if (!IS_ERR(clk)) {
+ of_clk_add_provider(np, of_clk_src_simple_get, clk);
+ clk_register_clkdev(clk, clk_name, NULL);
+ pr_debug("Add %s clock PLL\n", clk_name);
+ }
+}
+
+static void xgene_socpllclk_init(struct device_node *np)
+{
+ xgene_pllclk_init(np, PLL_TYPE_SOC);
+}
+
+static void xgene_pcppllclk_init(struct device_node *np)
+{
+ xgene_pllclk_init(np, PLL_TYPE_PCP);
+}
+
+/* IP Clock */
+struct xgene_dev_parameters {
+ void __iomem *csr_reg; /* CSR for IP clock */
+ u32 reg_clk_offset; /* Offset to clock enable CSR */
+ u32 reg_clk_mask; /* Mask bit for clock enable */
+ u32 reg_csr_offset; /* Offset to CSR reset */
+ u32 reg_csr_mask; /* Mask bit for disable CSR reset */
+ void __iomem *divider_reg; /* CSR for divider */
+ u32 reg_divider_offset; /* Offset to divider register */
+ u32 reg_divider_shift; /* Bit shift to divider field */
+ u32 reg_divider_width; /* Width of the bit to divider field */
+};
+
+struct xgene_clk {
+ struct clk_hw hw;
+ const char *name;
+ spinlock_t *lock;
+ struct xgene_dev_parameters param;
+};
+
+#define to_xgene_clk(_hw) container_of(_hw, struct xgene_clk, hw)
+
+static int xgene_clk_enable(struct clk_hw *hw)
+{
+ struct xgene_clk *pclk = to_xgene_clk(hw);
+ unsigned long flags = 0;
+ u32 data;
+
+ if (pclk->lock)
+ spin_lock_irqsave(pclk->lock, flags);
+
+ if (pclk->param.csr_reg != NULL) {
+ pr_debug("%s clock enabled\n", pclk->name);
+ /* First enable the clock */
+ data = xgene_clk_read(pclk->param.csr_reg +
+ pclk->param.reg_clk_offset);
+ data |= pclk->param.reg_clk_mask;
+ xgene_clk_write(data, pclk->param.csr_reg +
+ pclk->param.reg_clk_offset);
+ pr_debug("%s clock PADDR base 0x%016LX clk offset 0x%08X mask 0x%08X value 0x%08X\n",
+ pclk->name, __pa(pclk->param.csr_reg),
+ pclk->param.reg_clk_offset, pclk->param.reg_clk_mask,
+ data);
+
+ /* Second enable the CSR */
+ data = xgene_clk_read(pclk->param.csr_reg +
+ pclk->param.reg_csr_offset);
+ data &= ~pclk->param.reg_csr_mask;
+ xgene_clk_write(data, pclk->param.csr_reg +
+ pclk->param.reg_csr_offset);
+ pr_debug("%s CSR RESET PADDR base 0x%016LX csr offset 0x%08X mask 0x%08X value 0x%08X\n",
+ pclk->name, __pa(pclk->param.csr_reg),
+ pclk->param.reg_csr_offset, pclk->param.reg_csr_mask,
+ data);
+ }
+
+ if (pclk->lock)
+ spin_unlock_irqrestore(pclk->lock, flags);
+
+ return 0;
+}
+
+static void xgene_clk_disable(struct clk_hw *hw)
+{
+ struct xgene_clk *pclk = to_xgene_clk(hw);
+ unsigned long flags = 0;
+ u32 data;
+
+ if (pclk->lock)
+ spin_lock_irqsave(pclk->lock, flags);
+
+ if (pclk->param.csr_reg != NULL) {
+ pr_debug("%s clock disabled\n", pclk->name);
+ /* First put the CSR in reset */
+ data = xgene_clk_read(pclk->param.csr_reg +
+ pclk->param.reg_csr_offset);
+ data |= pclk->param.reg_csr_mask;
+ xgene_clk_write(data, pclk->param.csr_reg +
+ pclk->param.reg_csr_offset);
+
+ /* Second disable the clock */
+ data = xgene_clk_read(pclk->param.csr_reg +
+ pclk->param.reg_clk_offset);
+ data &= ~pclk->param.reg_clk_mask;
+ xgene_clk_write(data, pclk->param.csr_reg +
+ pclk->param.reg_clk_offset);
+ }
+
+ if (pclk->lock)
+ spin_unlock_irqrestore(pclk->lock, flags);
+}
+
+static int xgene_clk_is_enabled(struct clk_hw *hw)
+{
+ struct xgene_clk *pclk = to_xgene_clk(hw);
+ u32 data = 0;
+
+ if (pclk->param.csr_reg != NULL) {
+ pr_debug("%s clock checking\n", pclk->name);
+ data = xgene_clk_read(pclk->param.csr_reg +
+ pclk->param.reg_clk_offset);
+ pr_debug("%s clock is %s\n", pclk->name,
+ data & pclk->param.reg_clk_mask ? "enabled" :
+ "disabled");
+ }
+
+ if (pclk->param.csr_reg == NULL)
+ return 1;
+ return data & pclk->param.reg_clk_mask ? 1 : 0;
+}
+
+static unsigned long xgene_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct xgene_clk *pclk = to_xgene_clk(hw);
+ u32 data;
+
+ if (pclk->param.divider_reg) {
+ data = xgene_clk_read(pclk->param.divider_reg +
+ pclk->param.reg_divider_offset);
+ data >>= pclk->param.reg_divider_shift;
+ data &= (1 << pclk->param.reg_divider_width) - 1;
+
+ pr_debug("%s clock recalc rate %ld parent %ld\n",
+ pclk->name, parent_rate / data, parent_rate);
+ return parent_rate / data;
+ } else {
+ pr_debug("%s clock recalc rate %ld parent %ld\n",
+ pclk->name, parent_rate, parent_rate);
+ return parent_rate;
+ }
+}
+
+static int xgene_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct xgene_clk *pclk = to_xgene_clk(hw);
+ unsigned long flags = 0;
+ u32 data;
+ u32 divider;
+ u32 divider_save;
+
+ if (pclk->lock)
+ spin_lock_irqsave(pclk->lock, flags);
+
+ if (pclk->param.divider_reg) {
+ /* Let's compute the divider */
+ if (rate > parent_rate)
+ rate = parent_rate;
+ divider_save = divider = parent_rate / rate; /* Rounded down */
+ divider &= (1 << pclk->param.reg_divider_width) - 1;
+ divider <<= pclk->param.reg_divider_shift;
+
+ /* Set new divider */
+ data = xgene_clk_read(pclk->param.divider_reg +
+ pclk->param.reg_divider_offset);
+ data &= ~((1 << pclk->param.reg_divider_width) - 1);
+ data |= divider;
+ xgene_clk_write(data, pclk->param.divider_reg +
+ pclk->param.reg_divider_offset);
+ pr_debug("%s clock set rate %ld\n", pclk->name,
+ parent_rate / divider_save);
+ } else {
+ divider_save = 1;
+ }
+
+ if (pclk->lock)
+ spin_unlock_irqrestore(pclk->lock, flags);
+
+ return parent_rate / divider_save;
+}
+
+static long xgene_clk_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct xgene_clk *pclk = to_xgene_clk(hw);
+ unsigned long parent_rate = *prate;
+ u32 divider;
+
+ if (pclk->param.divider_reg) {
+ /* Let's compute the divider */
+ if (rate > parent_rate)
+ rate = parent_rate;
+ divider = parent_rate / rate; /* Rounded down */
+ } else {
+ divider = 1;
+ }
+
+ return parent_rate / divider;
+}
+
+const struct clk_ops xgene_clk_ops = {
+ .enable = xgene_clk_enable,
+ .disable = xgene_clk_disable,
+ .is_enabled = xgene_clk_is_enabled,
+ .recalc_rate = xgene_clk_recalc_rate,
+ .set_rate = xgene_clk_set_rate,
+ .round_rate = xgene_clk_round_rate,
+};
+
+static struct clk *xgene_register_clk(struct device *dev,
+ const char *name, const char *parent_name,
+ struct xgene_dev_parameters *parameters, spinlock_t *lock)
+{
+ struct xgene_clk *apmclk;
+ struct clk *clk;
+ struct clk_init_data init;
+ int rc;
+
+ /* allocate the APM clock structure */
+ apmclk = kzalloc(sizeof(*apmclk), GFP_KERNEL);
+ if (!apmclk) {
+ pr_err("%s: could not allocate APM clk\n", __func__);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ init.name = name;
+ init.ops = &xgene_clk_ops;
+ init.flags = 0;
+ init.parent_names = parent_name ? &parent_name : NULL;
+ init.num_parents = parent_name ? 1 : 0;
+
+ apmclk->name = name;
+ apmclk->lock = lock;
+ apmclk->hw.init = &init;
+ apmclk->param = *parameters;
+
+ /* Register the clock */
+ clk = clk_register(dev, &apmclk->hw);
+ if (IS_ERR(clk)) {
+ pr_err("%s: could not register clk %s\n", __func__, name);
+ kfree(apmclk);
+ return clk;
+ }
+
+ /* Register the clock for lookup */
+ rc = clk_register_clkdev(clk, name, NULL);
+ if (rc != 0) {
+ pr_err("%s: could not register lookup clk %s\n",
+ __func__, name);
+ }
+ return clk;
+}
+
+static void __init xgene_devclk_init(struct device_node *np)
+{
+ const char *clk_name = np->full_name;
+ struct clk *clk;
+ struct resource res;
+ int rc;
+ struct xgene_dev_parameters parameters;
+ int i;
+
+ /* Check if the entry is disabled */
+ if (!of_device_is_available(np))
+ return;
+
+ /* Parse the DTS register for resource */
+ parameters.csr_reg = NULL;
+ parameters.divider_reg = NULL;
+ for (i = 0; i < 2; i++) {
+ void *map_res;
+ rc = of_address_to_resource(np, i, &res);
+ if (rc != 0) {
+ if (i == 0) {
+ pr_err("no DTS register for %s\n",
+ np->full_name);
+ return;
+ }
+ break;
+ }
+ map_res = of_iomap(np, i);
+ if (map_res == NULL) {
+ pr_err("Unable to map resource %d for %s\n",
+ i, np->full_name);
+ goto err;
+ }
+ if (strcmp(res.name, "div-reg") == 0)
+ parameters.divider_reg = map_res;
+ else /* if (strcmp(res->name, "csr-reg") == 0) */
+ parameters.csr_reg = map_res;
+ }
+ if (of_property_read_u32(np, "csr-offset", &parameters.reg_csr_offset))
+ parameters.reg_csr_offset = 0;
+ if (of_property_read_u32(np, "csr-mask", &parameters.reg_csr_mask))
+ parameters.reg_csr_mask = 0xF;
+ if (of_property_read_u32(np, "enable-offset",
+ &parameters.reg_clk_offset))
+ parameters.reg_clk_offset = 0x8;
+ if (of_property_read_u32(np, "enable-mask", &parameters.reg_clk_mask))
+ parameters.reg_clk_mask = 0xF;
+ if (of_property_read_u32(np, "divider-offset",
+ &parameters.reg_divider_offset))
+ parameters.reg_divider_offset = 0;
+ if (of_property_read_u32(np, "divider-width",
+ &parameters.reg_divider_width))
+ parameters.reg_divider_width = 0;
+ if (of_property_read_u32(np, "divider-shift",
+ &parameters.reg_divider_shift))
+ parameters.reg_divider_shift = 0;
+ of_property_read_string(np, "clock-output-names", &clk_name);
+
+ clk = xgene_register_clk(NULL, clk_name,
+ of_clk_get_parent_name(np, 0), &parameters, &clk_lock);
+ if (IS_ERR(clk))
+ goto err;
+ pr_debug("Add %s clock\n", clk_name);
+ rc = of_clk_add_provider(np, of_clk_src_simple_get, clk);
+ if (rc != 0)
+ pr_err("%s: could register provider clk %s\n", __func__,
+ np->full_name);
+
+ return;
+
+err:
+ if (parameters.csr_reg)
+ iounmap(parameters.csr_reg);
+ if (parameters.divider_reg)
+ iounmap(parameters.divider_reg);
+}
+
+CLK_OF_DECLARE(xgene_socpll_clock, "apm,xgene-socpll-clock", xgene_socpllclk_init);
+CLK_OF_DECLARE(xgene_pcppll_clock, "apm,xgene-pcppll-clock", xgene_pcppllclk_init);
+CLK_OF_DECLARE(xgene_dev_clock, "apm,xgene-device-clock", xgene_devclk_init);
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-30 16:29:06 +0000