diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/imx/clk.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c new file mode 100644 index 000000000..d4cf0c704 --- /dev/null +++ b/drivers/clk/imx/clk.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bits.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include "clk.h" + +#define CCM_CCDR 0x4 +#define CCDR_MMDC_CH0_MASK BIT(17) +#define CCDR_MMDC_CH1_MASK BIT(16) + +DEFINE_SPINLOCK(imx_ccm_lock); +EXPORT_SYMBOL_GPL(imx_ccm_lock); + +void imx_unregister_clocks(struct clk *clks[], unsigned int count) +{ + unsigned int i; + + for (i = 0; i < count; i++) + clk_unregister(clks[i]); +} + +void imx_unregister_hw_clocks(struct clk_hw *hws[], unsigned int count) +{ + unsigned int i; + + for (i = 0; i < count; i++) + clk_hw_unregister(hws[i]); +} +EXPORT_SYMBOL_GPL(imx_unregister_hw_clocks); + +void imx_mmdc_mask_handshake(void __iomem *ccm_base, + unsigned int chn) +{ + unsigned int reg; + + reg = readl_relaxed(ccm_base + CCM_CCDR); + reg |= chn == 0 ? CCDR_MMDC_CH0_MASK : CCDR_MMDC_CH1_MASK; + writel_relaxed(reg, ccm_base + CCM_CCDR); +} + +void imx_check_clocks(struct clk *clks[], unsigned int count) +{ + unsigned i; + + for (i = 0; i < count; i++) + if (IS_ERR(clks[i])) + pr_err("i.MX clk %u: register failed with %ld\n", + i, PTR_ERR(clks[i])); +} + +void imx_check_clk_hws(struct clk_hw *clks[], unsigned int count) +{ + unsigned int i; + + for (i = 0; i < count; i++) + if (IS_ERR(clks[i])) + pr_err("i.MX clk %u: register failed with %ld\n", + i, PTR_ERR(clks[i])); +} +EXPORT_SYMBOL_GPL(imx_check_clk_hws); + +static struct clk *imx_obtain_fixed_clock_from_dt(const char *name) +{ + struct of_phandle_args phandle; + struct clk *clk = ERR_PTR(-ENODEV); + char *path; + + path = kasprintf(GFP_KERNEL, "/clocks/%s", name); + if (!path) + return ERR_PTR(-ENOMEM); + + phandle.np = of_find_node_by_path(path); + kfree(path); + + if (phandle.np) { + clk = of_clk_get_from_provider(&phandle); + of_node_put(phandle.np); + } + return clk; +} + +struct clk *imx_obtain_fixed_clock( + const char *name, unsigned long rate) +{ + struct clk *clk; + + clk = imx_obtain_fixed_clock_from_dt(name); + if (IS_ERR(clk)) + clk = imx_clk_fixed(name, rate); + return clk; +} + +struct clk_hw *imx_obtain_fixed_clock_hw( + const char *name, unsigned long rate) +{ + struct clk *clk; + + clk = imx_obtain_fixed_clock_from_dt(name); + if (IS_ERR(clk)) + clk = imx_clk_fixed(name, rate); + return __clk_get_hw(clk); +} + +struct clk_hw * imx_obtain_fixed_clk_hw(struct device_node *np, + const char *name) +{ + struct clk *clk; + + clk = of_clk_get_by_name(np, name); + if (IS_ERR(clk)) + return ERR_PTR(-ENOENT); + + return __clk_get_hw(clk); +} +EXPORT_SYMBOL_GPL(imx_obtain_fixed_clk_hw); + +/* + * This fixups the register CCM_CSCMR1 write value. + * The write/read/divider values of the aclk_podf field + * of that register have the relationship described by + * the following table: + * + * write value read value divider + * 3b'000 3b'110 7 + * 3b'001 3b'111 8 + * 3b'010 3b'100 5 + * 3b'011 3b'101 6 + * 3b'100 3b'010 3 + * 3b'101 3b'011 4 + * 3b'110 3b'000 1 + * 3b'111 3b'001 2(default) + * + * That's why we do the xor operation below. + */ +#define CSCMR1_FIXUP 0x00600000 + +void imx_cscmr1_fixup(u32 *val) +{ + *val ^= CSCMR1_FIXUP; + return; +} + +#ifndef MODULE + +static bool imx_keep_uart_clocks; +static int imx_enabled_uart_clocks; +static struct clk **imx_uart_clocks; + +static int __init imx_keep_uart_clocks_param(char *str) +{ + imx_keep_uart_clocks = 1; + + return 0; +} +__setup_param("earlycon", imx_keep_uart_earlycon, + imx_keep_uart_clocks_param, 0); +__setup_param("earlyprintk", imx_keep_uart_earlyprintk, + imx_keep_uart_clocks_param, 0); + +void imx_register_uart_clocks(unsigned int clk_count) +{ + imx_enabled_uart_clocks = 0; + +/* i.MX boards use device trees now. For build tests without CONFIG_OF, do nothing */ +#ifdef CONFIG_OF + if (imx_keep_uart_clocks) { + int i; + + imx_uart_clocks = kcalloc(clk_count, sizeof(struct clk *), GFP_KERNEL); + + if (!of_stdout) + return; + + for (i = 0; i < clk_count; i++) { + imx_uart_clocks[imx_enabled_uart_clocks] = of_clk_get(of_stdout, i); + + /* Stop if there are no more of_stdout references */ + if (IS_ERR(imx_uart_clocks[imx_enabled_uart_clocks])) + return; + + /* Only enable the clock if it's not NULL */ + if (imx_uart_clocks[imx_enabled_uart_clocks]) + clk_prepare_enable(imx_uart_clocks[imx_enabled_uart_clocks++]); + } + } +#endif +} + +static int __init imx_clk_disable_uart(void) +{ + if (imx_keep_uart_clocks && imx_enabled_uart_clocks) { + int i; + + for (i = 0; i < imx_enabled_uart_clocks; i++) { + clk_disable_unprepare(imx_uart_clocks[i]); + clk_put(imx_uart_clocks[i]); + } + } + + kfree(imx_uart_clocks); + + return 0; +} +late_initcall_sync(imx_clk_disable_uart); +#endif + +MODULE_LICENSE("GPL v2"); |